Software for Manipulating or Displaying NetCDF Data This document provides references to software packages that may be used for manipulating or displaying netCDF data. We include information about both freely-available and licensed (commercial) software that can be used with netCDF data. We rely on developers to help keep this list up-to-date. If you know of corrections or additions, please send them to us. Where practical, we would like to include WWW links to information about these packages in the HTML version of this document at <http://www.unidata.ucar.edu/packages/netcdf/software.html>. Another guide to netCDF utilities is available from http://www.gfdl.gov/~jps/GFDL_VG_NetCDF_Utils.html. ------------------------------------------------------------------ Freely Available Software * ARGOS * CDAT * CIDS Tools * CRDtools * CSIRO MATLAB/netCDF interface * DDI * DODS * Envision * EPIC * EzGet * FAN * FERRET * FREUD * GMT * Grace * GrADS * Gri * HDF interface * HIPHOP * HOPS * Ingrid * IVE * Java interface * LinkWinds * MexEPS * ncBrowse * NCO * ncview * NetCDF File Calculator and Data Editor * Netcdf to HDF converter * NetCDF Toolbox for MATLAB-5 * OpenDX (formerly IBM Data Explorer) * PolyPaint+ * Python interfaces * Tcl/Tk interface * SciAn * VisAD * WebWinds * Xmgr * Zebra * User-contributed software ------------------------------------------------------------------ Commercial or Licensed Packages * AVS * Environmental WorkBench * IDL Interface * InterFormat * IRIS Explorer Module * MATLAB * NCAR Graphics * Noesys * PPLUS * PV-Wave * Slicer Dicer * VISAGE and Decimate * WXP ------------------------------------------------------------------ ARGOS ARGOS (interActive thRee-dimensional Graphics ObServatory) is a new IDL based interactive 3D visualization tool, developed by David N. Bresch and Mark A. Liniger at the Institute for Atmospheric Science at the Swiss Federal Institute of Technology, ETH, Zürich. A highly optimized graphical user interface allows quick and elegant creation of even complex 3D graphics (volume rendering, isosurfaces,...), including Z-buffered overlays (with hidden lines), light and data shading, Xray images, 3D trajectories, animations and virtual flights around your data, all documented in a full on-line html-help. The netCDF data format is preferred, but any other format can be read by providing an IDL (or FORTRAN or C or C++) interface. Some toolboxes (for atmospheric model output, trajectory display, radar data) have already been written, others might easily be added (in IDL, FORTRAN or C code). All interactive activities are tracked in a script, allowing quick reconstruction of anything done as well as running ARGOS in batch script mode. Information about copyright and licensing conditions are available. For further information and installation, please E-mail to: bresch@atmos.umnw.ethz.ch CDAT The Climate Data Analysis Tool (CDAT), developed by the Program for Climate Model Diagnosis and Intercomparison (PCMDI) at Lawrence Livermore National Laboratory, provides the capabilities needed to analyze model data, perform complex mathematical calculations, and graphically display the results. It provides the necessary tools to diagnose, validate, and intercompare large observational and global climate model data sets. It includes the ability to ingest ... large climate datasets in netCDF, HDF, DRS, and GrADS/GRIB format; the Visualization and Computation System (VCS) module, visually displays and animates ingested or created data; and the Library of AMIP Data Transmission Standards (LATS) module, outputs data in the machine-independent netCDF or GrADS/GRIB file formats. ... In addition, the Command Line Interface (CLI) module allows CDAT to receive argument and function input via the command line and the Graphical User Interface (GUI) allows CDAT to receive argument and function input via a point-and-click environment. ... The software, which runs as a standalone process or within PCMDI's Visualization and Computation System (VCS), provides climate scientists with an easy and fast method to read different file formats, and to analyze and graphically display climate data in an integrated fashion. CDAT includes a set of pre-defined functions to allow the user to manipulate the data and send the output to a file which can be viewed as an image, or as a collection of images in an animation. The software has a gradual learning curve, allowing the novice user to quickly obtain useful results. CIDS Tools The Center for Clouds Chemistry and Climate (C4) Integrated Data Systems (CIDS) group has developed several useful netCDF utilities: * cdf2idl: Writes an IDL script to read a NetCDF file. * cdf2c: Writes C code to read a NetCDF file. * cdf2fortran: Writes FORTRAN source code to read a NetCDF file. * cdf2asc: Dumps NetCDF data to an ASCII file. The source for these utilities can be downloaded from CIDS NetCDF Visualization Tools site. CRDtools Climate Research Data Tools (CRDtools) provides data extraction, analysis, and visualization functions for the climatology researcher. This toolkit of X Windows applications was developed at the NOAA Climate Diagnostics Center. CRDtools is written in C and uses the NCAR Graphics plotting package to display some of its output. In addition to netCDF, you will need the NCAR graphics package to use CRDtools. * Current release information. * CRDtools installation instructions For additional CRDtools help, contact crdtools@cdc.noaa.gov. CSIRO MATLAB/netCDF interface The CSIRO MATLAB/netCDF interface is now available from the CSIRO Marine Laboratories. The CSIRO MATLAB/netCDF interface is run from within MATLAB and has a simple syntax. It has options for automatically handling missing values, scale factors, and permutation of hyperslabs. It is, however, limited to retrieving data from, and information about, existing netCDF files. The basis of the interface is a machine-dependent mex-file called mexcdf53 (an older version running under matlab4 used mexcdf). Rather than call the mex-file directly users are advised to employ both Chuck Denham's netCDF toolbox and the CSIRO MATLAB/netCDF interface described here. For read-only access to existing netCDF data, the CSIRO interface has a simpler syntax than the netCDF Toolbox, but the latter may also be used to create and manipulate netCDF variables and datasets. DDI The Data and Dimensions Interface (DDI) addresses a significant problem in the visualization of large data sets: Extracting only the relevant data and providing it to a chosen graphics engine in the required form without undue effort. DDI transfers data between files, formats and visualization systems. It works within the specifications of each supported format to promote compatibility. DDI provides the following capabilities: * Browsing through the contents of DRS, NetCDF, and HDF files * Randomly selecting data variables * Rearranging variables into the desired form * Modifying or creating new variable attributes * Saving variables into new files * Feeding variables directly to a visualization system DDI operates in two modes: * As a module in a data flow environment such as AVS or IRIS Explorer * As a stand-alone application capable of sending data over the network to AVS, IRIS Explorer, IDL, NCSA Collage, and PV-WAVE DDI is available for a number of computer systems via anonymous FTP. The Introduction to DDI and DDI Reference Manual are WWW-accessible: http://www-pcmdi.llnl.gov/software/ddi/ DDI was developed as a collaboration between the Program for Climate Model Diagnosis and Intercomparison (PCMDI), and the National Energy Research Supercomputer Center (NERSC), both of Lawrence Livermore National Laboratory (LLNL). DDI was developed by Chris L. Anderson, Robert S. Drach, and Dean N. Williams. DODS The Distributed Oceanographic Data System (DODS) is an effort to facilitate widespread exchange of scientific data sets between scientists over the Internet. DODS is based on existing data access tools; rather than developing a self contained system, it makes extensive use of existing data access APIs and the World Wide Web. DODS is being developed by the University of Rhode Island and the Massachusetts Institute of Technology. DODS can be used to make netCDF data files available over the Internet and it can also be used to adapt existing software which use the netCDF API (by re-linking) to read data served by a DODS data server. In principle, any program written using netCDF can be adapted to read data from a DODS data server - in other words any program which uses netcdf can become a client in the DODS client-server system. Included in the source and binary distributions are two freely available programs which have already been modified (re-linked). With a client program accessing data from a netCDF server, it is possible access a small subset of a large dataset over the Internet without copying the entire dataset (as you would have to do with FTP or AFS). The client can see changes to the netCDF dataset, e.g. when new records are added (which would not be possible with FTP). Finally, the client can also access cross-sections of variable data without paging large amounts of data across the network (as you would have to do with NFS, for example). While DODS currently supports netCDF only, the developers plan support for other data access APIs including JGOFS. As new APIs are added to DODS, existing clients will be able to read any of those data sets, even those stored in a `foreign' API or format. The first beta release of DODS software is freely available via anonymous ftp in both source form (you will need the GNU C++ compiler and libg++) or binary form for selected platforms. Envision Envision is an interactive system for the management and visualization of large scientific data sets. It runs on UNIX workstations under X/Motif, manages data stored in netCDF or HDF files, and does visualization using NCSA Collage, NCSA XDataSlice, and IDL. Envision is public domain software and is available by anonymous FTP. The primary ftp site for Envision is vista.atmos.uiuc.edu in pub/envision. A secondary FTP site is csrp.tamu.edu. Included in the release are binaries for IBM RS6000, HP, Sun, and SGI, as well as source and make files. Complete documentation, sample data, and binaries to generate Envision project files for the sample data are provided. Envision was jointly developed at the Department of Atmospheric Sciences at University of Illinois at Urbana-Champaign and the Department of Meteorology at Texas A&M University, with funding from NASA's Applied Information Systems Research Program. For further information, contact Keith Searight (krs@cdc.noaa.gov). EPIC NOAA's Pacific Marine Environmental Laboratory (PMEL) has developed the EPIC software package for oceanographic data. EPIC provides graphical display and data field manipulation for multi-dimensional netCDF files (up to 4 dimensions). PMEL has been using this software on Unix and VMS several years. At present, they have: * a data file I/O library ( epslib, which is layered on top of the netCDF library). * epslib allows transparent access to multiple data file formats * a MATLAB MexEPS interface for using any supported EPIC file with MATLAB * suite of EPIC programs for graphics and analysis of hydrographic profile data and time series data. This software was developed on Sun/Unix and is also supported for DEC/Ultrix and VAX/VMS as a system for data management, display and analysis system for observational oceanographic time series and hydrographic data. The EPIC software includes over 50 programs for oceanographic display and analysis, as well as utilities for putting in-situ or observational data on-line (with on-the-fly graphics and data download) on the WWW. The developers are interested in coordinating with others who may be developing oceanographic software for use with netCDF files. The EPIC software is available via anonymous FTP from ftp.noaapmel.gov in the epic/ and /eps directories. To obtain the EPIC software, please see Web pages at http://www.pmel.noaa.gov/epic/epic-toolkits.html. For information about EPIC, please see the Web pages at http://www.pmel.noaa.gov/epic/home.html. Contact epic@pmel.noaa.gov, or Nancy Soreide, nns@noaapmel.gov, for more information. EzGet A FORTRAN library called EzGet has been developed at PCMDI to facilitate retrieval of modeled and observed climate data stored in popular formats including DRS, netCDF, GrADS, and, if a control file is supplied, GRIB. You can specify how the data should be structured and whether it should undergo a grid transformation before you receive it, even when you know little about the original structure of the stored data (e.g., its original dimension order, grid, and domain). The EzGet library comprises a set of subroutines that can be linked to any FORTRAN program. EzGet reads files through the cdunif interface, but use of EzGet does not require familiarity with cdunif. The main advantages of using EzGet instead of the lower level cdunif library include: * Substantial error trapping capabilities and detailed error messages * Versatile capability of conveniently selecting data from specified regions (e.g., oceans, North America, all land areas north of 45 degrees latitude, etc.) * Ability to map data to a new grid at the time it is retrieved by EzGet * Automatic creation of ``weights'' for use in subsequent averaging or masking of data * Increased control in specifying the domain of the data to be retrieved. For more information about EzGet, including instructions for downloading the documentation or software, see the EzGet home page at http://www-pcmdi.llnl.gov/ktaylor/ezget/ezget.html. For questions or comments on EzGet, contact Karl Taylor (taylor13@llnl.gov). FAN FAN (File Array Notation) is Harvey Davies' package for extracting and manipulating array data from netCDF files. The package includes the three utilities nc2text, text2nc, and ncrob for printing selected data from netCDF arrays, copying ASCII data into netCDF arrays, and performing various operations (sum, mean, max, min, product, ...) on netCDF arrays. A library (fanlib) is also included that supports the use of FAN from C programs. The package is available via anonymous FTP from ftp://ftp.unidata.ucar.edu/pub/netcdf/contrib/fan.tar.Z. Questions and comments may be sent to Harvey Davies, hld@dar.csiro.au. FERRET FERRET is an interactive computer visualization and analysis environment designed to meet the needs of oceanographers and meteorologists analyzing large and complex gridded data sets. It is available by anonymous ftp from abyss.pmel.noaa.gov for a number of computer systems: SUN (Solaris and SUNOS), DECstation (Ultrix and OSF/1), SGI, VAX/VMS and Macintosh (limited support), and IBM RS-6000 (soon to be released). FERRET offers a Mathematica-like approach to analysis; new variables may be defined interactively as mathematical expressions involving data set variables. Calculations may be applied over arbitrarily shaped regions. Fully documented graphics are produced with a single command. Graphics styles included line plots, scatter plots, contour plots, color-filled contour plots, vector plots, wire frame plots, etc. Detailed controls over plot characteristics, page layout and overlays are provided. NetCDF is supported both as an input and an output format. Many excellent software packages have been developed recently for scientific visualization. The features that make FERRET distinctive among these packages are Mathematica-like flexibility, geophysical formatting (latitude/longitude/date), "intelligent" connection to its data base, special memory management for very large calculations, and symmetrical processing in 4 dimensions. Contact Steve Hankin, hankin@noaapmel.gov, for more information. FREUD Freud is a software environment that facilitates the production of publication quality contour and vector plots. While there are many public domain and commercial software packages that allow users to create contour and vector plots, Freud is unique in that users can quickly and easily customize the appearance of contour lines, contour fills, map projections, or vector arrows with a couple of mouse clicks. Freud allows researchers to: * create an unlimited number of contour and vector plot overlays that can be superimposed on up to six different map backgrounds. * interactively position an unlimited number of plots of any size at any position on a plotting page. * set the line style, line color, fill pattern, and fill color of contours, vectors or map background. * read in data in netCDF, binary, or ASCII data formats. * browse through netCDF variable attributes. * create scripts to automate plots by using extensions to the procedural scripting language TCL. * save a set of overlays to restore a given plot at a later date. For more information, contact Joe Sirott (sirott@atmos.washington.edu). GMT GMT (Generic Mapping Tools) is a free, public-domain collection of about 50 UNIX tools that allow users to manipulate two- and three-dimensional data sets (including filtering, trend fitting, gridding, projecting, etc.) and produce Encapsulated PostScript File (EPS) illustrations ranging from simple x-y plots through contour maps to artificially illuminated surfaces and 3-D perspective views in black and white, gray tone, hachure patterns, and 24-bit color. GMT supports 20 common map projections plus linear, log, and power scaling, and comes with support data such as coastlines, rivers, and political boundaries. Version 3.0 was recently announced in "New Version of the Generic Mapping Tools Released," EOS Trans., AGU 72, 329. The package can access netCDF data as well as ASCII, native binary, or user-defined formats. The GMT package is available via anonymous ftp from several servers. Because of file sizes you are strongly encouraged to use the closest server: * kiawe.soest.hawaii.edu in /pub/gmt. [Hawaii, US] Serving Asia/Australia/Pacific * ibis.grdl.noaa.gov in /pub/gmt. [Maryland, US] Serving North and South America * ftp.geologi.uio.no in /pub/gmt. [Oslo, Norway] Serving Europe GMT was developed and is maintained by Paul Wessel (wessel@soest.hawaii.edu) and Walter H. F. Smith (walter@amos.grdl.noaa.gov). Grace Grace is a tool to make two-dimensional plots of scientific data. It runs under the X Window System and OSF Motif (recent versions of LessTif are, by and large, fine, too). Grace runs on practically any version of Unix. As well, it has been successfully ported to VMS, OS/2 and Win9*/NT (some functionality may be missing, though). Grace is a descendant of ACE/gr, also known as Xmgr. A few features of Grace are: * User defined scaling, tick marks, labels, symbols, line styles, colors. * Batch mode for unattended plotting. * Read and write parameters used during a session. * Regressions, splines, running averages, DFT/FFT, cross/auto-correlation, ... * Support for dynamic module loading. * Hardcopy support for PostScript, PDF, GIF, and PNM formats. * Device-independent Type1 font rastering. * Ability to read or write netCDF data. GrADS GrADS (Grid Analysis and Display System) is an interactive desktop tool from COLA/IGES that is currently in use worldwide for the analysis and display of earth science data. GrADS is implemented on all commonly available UNIX workstations, Apple Macintosh, and DOS or Linux based PCs, and is freely available via anonymous ftp. GrADS provides an integrated environment for access, manipulation, and display of earth science data. The SDF (Self-Describing Files) interface to GrADS is available for UNIX platforms and permits reading netCDF or HDF-SDS files ( with some restrictions). SDF will be distributed with GrADS version 1.6. For additional info on the GrADS SDF interface, contact Don Hooper at hoop@cdc.noaa.gov. Gri Gri is an extensible plotting language for producing scientific graphs, such as x-y plots, contour plots, and image plots. Dan Kelley of Dalhousie University is the author of Gri, which can read data from netCDF files as well as ASCII and native binary data. For more information on Gri, see the URL http://www.phys.ocean.dal.ca/~kelley/gri/gri1.html. HDF interface The National Center for Supercomputing Applications (NCSA) has added the netCDF interface to their Hierarchical Data Format (HDF) software. HDF is an extensible data format for self-describing files. A substantial set of applications and utilities based on HDF is available; these support raster-image manipulation and display and browsing through multidimensional scientific data. An implementation is now available that provides the netCDF interface to HDF. With this software, it is possible to use the netCDF calling interface to place data into an HDF file. The netCDF calling interface has not changed and netCDF files stored in XDR format are readable, so existing programs and data will still be usable (although programs will need to be relinked to the new library). There is currently no support for the mixing of HDF and netCDF structures. For example, a raster image can exist in the same file as a netCDF object, but you have to use the Raster Image interface to read the image and the netCDF interface to read the netCDF object. The other HDF interfaces are currently being modified to allow multi-file access, closer integration with the netCDF interface will probably be delayed until the end of that project. Eventually, it will be possible to integrate netCDF objects with the rest of the HDF tool suite. Such an integration will then allow tools written for netCDF and tools written for HDF to both interact intelligently with the new data files. OpenDX OpenDX (formerly IBM Data Explorer, also known as simply DX) is a general-purpose software package for data visualization and analysis. It employs a data-flow driven client-server execution model and provides a graphical program editor that allows the user to create a visualization using a point and click interface. DX runs on 7 major UNIX platforms as well as Windows 95/NT and is designed to take full advantage of multi-processor systems from IBM, SGI and Sun. DX is built upon an internal data model, which describes and provides uniform access services for any data brought into, generated by, or exported from the software. This data model supports a number of different classes of scientific data, which can be described by their shape (size and number of dimensions), rank (e.g., scalar, vector, tensor), type (float, integer, byte, etc. or real, complex, quaternion), where the data are located in space (positions), how the locations are related to each other (connections), aggregates or groups (e.g., hierarchies, series, composites, multizone grids, etc.). It also supports those entities required for graphics and imaging operations within the context of Data Explorer. Regular and irregular, deformed or curvilinear, structured and unstructured data as well as "missing" or invalid data are supported. The details of the data model are hidden at the user level. As a result DX operations or modules are polymorphic and appear typeless. The DX Import module, which reads data for use within Data Explorer directly utilizes data in netCDF as well as other formats (e.g., HDF, CDF). One or more variables may be selected as well as step(s) of a time series. Data in conventional netCDFs are directly imported. Since the DX data model is more comprehensive than the netCDF data model, a methodology to extend netCDF via attribute conventions (e.g., for unstructured meshes, non-scalar data and hierarchies) for use with Data Explorer is available. DX supports a number of realization techniques for generating renderable geometry from data. These include color and opacity mapping (e.g., for surface and volume rendering), contours and isosurfaces, histograms, two-dimensional and three-dimensional plotting, surface deformation, etc. for scalar data. For vector data, arrow plots, streamlines, streaklines, etc. are provided. Realizations may be annotated with ribbons, tubes, axes, glyphs, text and display of data locations, meshes and boundaries. Data probing, picking, arbitrary surface and volume sampling, and arbitrary cutting/mapping planes are supported. DX supports a number of non-graphical functions such as point-wise mathematical expressions (e.g., arithmetic, transcendental, boolean, type conversion, etc.), univariate statistics and image processing (e.g., transformation, filter, warp, edge detection, convolution, equalization, blending, morphological operations, etc.). Field/vector operations such as divergence, gradient and curl, dot and cross products, etc. are provided. Non-gridded or scattered data may be interpolated to an arbitrary grid or triangulated, depending on the analysis requirements. The length, area or volume of various geometries may also be computed. Tools for data manipulation such as removal of data points, subsetting by position, sub/supersampling, grid construction, mapping, interpolation, regridding, transposition, etc. are available. Tools for doing cartographic projections and registration as well as earth, space and environmental sciences examples are available at Cornell University via info.tc.cornell.edu. HIPHOP HIPHOP, developed by Dominik Brunner, is a widget based IDL application that largely facilitates the visualization and analysis of 2D, 3D, and 4D atmospheric science data, in particular atmospheric tracer distributions and meteorological fields. Graphical output of (atmospheric model) data can be quickly generated in a large number of different ways, including horizontal maps at selected model or pressure levels, vertical north-south, east-west, or slant cross-sections (including zonal averages), time slices, animations, etc. It also allows mathematical operations on the existing fields to generate new fields for furher analysis, and it can be run as a batch application. The program handles data in netCDF, HDF and GRIB format. Interfaces to other data formats (e.g. ASCII and binary data) can be added easily. Beginning with Version 4.0, it also supports the ability to overlay meteorological fields on a number of different satellite images, and to draw air parcel trajectories. Hyperslab OPerator Suite (HOPS) Hyperslab OPerator Suite (HOPS), developed by R. Saravanan at NCAR, is a bilingual, multi-platform software package for processing data in netCDF files conforming to the NCAR-CCM format or the NCAR Ocean Model format. HOPS is implemented in IDL, the widely-used commercial interpreted language, and also in Yorick, a public-domain interpreted language that is freely available from the Lawrence Livermore National Laboratory. The IDL version of HOPS should run on any platform supported by IDL. The Yorick version too runs on most common UNIX platforms, such as Sun, SGI, Cray, and LINUX computers. HOPS is not a monolithic program, but a suite of operators that act on data units called "hyperslabs". The design of HOPS is object-oriented, rather than procedure-oriented; the operators treat the numeric data and the associated meta-data (like coordinate information) as a single object. Note that HOPS is not a general purpose netCDF utility and works only for the NCAR CSM netCDF formats. For more information, check the HOPS home page. Ingrid Ingrid, by M. Benno Blumenthal <benno@ldeo.columbia.edu>, is designed to manipulate large datasets and model input/output. Given the proper commands in its command file, it can read data from its data catalog, a netCDF file, or a directly attached model, and output the data, either by feeding it to a model, creating a netCDF file, or creating plots and other representations of the data. Ingrid has a number of filters which allow simple data manipulations, such as adding two datasets together, smoothing, averaging, and regridding to a new coordinate. Ingrid is still under development and the source code is not yet available for public release. It currently runs only on SGI (it uses the POINTER and STRUCTURE extensions to FORTRAN). In addition to netCDF, it also reads HDF, CDF, VOGL, and SGI GL. Ingrid is currently running as a WWW daemon that can be accessed through http://rainbow.ldgo.columbia.edu/datacatalog.html to see some of its capabilities on a climate data catalog maintained by the Climate Group of the Lamont-Doherty Earth Observatory of Columbia University. To quote the introduction: The Data Catalog is both a catalog and a library of datasets, i.e. it both helps you figure out which data you want, and helps you work with the data. The interface allows you to make plots, tables, and files from any dataset, its subsets, or processed versions thereof. This data server is designed to make data accessible to people using WWW clients (viewers) and to serve as a data resource for WWW documents. Since most documents cannot use raw data, the server is able to deliver the data in a variety of ways: as data files (netCDF and HDF), as tables (html), and in a variety of plots (line, contour, color, vector) and plot formats (PostScript and gif). Processing of the data, particularly averaging, can be requested as well. The Data Viewer in particular demonstrates the power of the Ingrid daemon. IVE IVE (Interactive Visualization Environment) is a software package designed to interactively display and analyze gridded data. IVE assumes the data to be displayed are contained in one- two-, three- or four-dimensional arrays. By default, the numbers within these arrays are assumed to represent grid point values of some field variable (such as pressure) on a rectangular evenly spaced grid. IVE is, nevertheless, capable of displaying data on arbitrary curvilinear grids. If the data points are not evenly spaced on a rectangular grid, IVE must be informed of the grid structure, either by specifying "attributes" in the data input or by specifying the coordinate transform in a user supplied subroutine. Stretched rectangular grids (which occur when the stretching along a given coordinate is a function only of the value of that coordinate) can be accommodated by specifying one-dimensional arrays containing the grid-point locations along the stretched coordinate as part of the IVE input data. Staggered meshes can also be accommodated by setting "attributes" in the input data. The structure of more complicated curvilinear grids must be communicated to IVE via user supplied "transforms," which define the mapping between physical space and the array indices. Since four-dimensional data cannot be directly displayed on a flat computer screen, it is necessary to reduced the dimensionality of the data before it is displayed. One of IVE's primary capabilities involves dimension reduction or "data slicing." IVE allows the user to display lower-dimensional subsets of the data by fixing a coordinate or by averaging over the coordinate. IVE currently has the capability to display * scalar fields as o 2D scalar plots o 1D scalar plots o vertical soundings o a single point value * vector fields as 2D vector plots IVE lets you overlay plots, loop plots, and control a wide variety of display parameters. IVE also can perform algebraic computations on the gridded data and can calculate derivatives. More complicated computations can be performed in user supplied subroutines. IVE uses NetCDF for the data input format, and uses the NCAR Graphics Library to produce graphical output (a license for NCAR Graphics is required to run IVE and can be obtained from the National Center for Atmospheric Research, NCAR). IVE is available as source via anonymous ftp; and as binary on request for licensees of NCAR graphics. Java interface A preliminary release of a Java netCDF implementation is available for testing. LinkWinds LinkWinds version 2.3 applies a unique data-linking paradigm resulting in a system which functions much like a graphical spreadsheet. It is not only a powerful method for organizing large amounts of data for analysis, but provides a highly intuitive, easy-to-learn, easy-to-retain user interface on top of the traditional graphical user interface. The linking of data displays and controls for their manipulation provides great flexibility in rapidly exploring large masses of complex data to quickly detect trends, correlations and anomalies. The system is comprised of a large and expanding suite of non-domain specific applications and provides for the ingestion of a variety of database formats. Its many functions and services include * 2-dimensional and 3-dimensional graphical displays of data. * The ability to deal with very large data files. * Interactive visual data subsetting either at the input or output * Supersetting to construct higher dimensionality data sets from sets of data files. This is useful for building time series from daily data accumulations. * Simultaneous display and analysis of multiple data sets which may be totally unrelated. * A unique and easy-to-use animation creation and display capability. * Interactive color manipulation. * A journal and macro capability allowing replay of an entire session or any portion thereof. * Hard copy of graphical displays and text. * A context-sensitive help system. * Network support for collaborative data analysis with partners anywhere on the internet, using virtually no bandwidth. * In addition to archived data sets, LinkWinds has demonstrated an ability to ingest and display real time data, which may be from spacecraft, laboratory experiments, or computer simulations. The data file formats accepted by LinkWinds 2.3 are: 1. Raw binary data in signed and unsigned 1, 2 and 4 byte integers and 4 and 8 byte floating point. 2. The Hierarchical Data Format (HDF). 3. The Common Data Format (CDF). 4. NetCDF. 5. The Silicon Graphics, Inc. native RGB image format. 6. Data with Planetary Data System (PDS) headers. 7. The astrophysics Flexible Image Transport System (FITS). 8. ASCII text data. 9. Two data formats of UARS, the Upper Atmosphere Research Satellite. Both the format maintained by the Goddard DAAC and the UNIX variant of the format of the Central Data Handling Facility (CDHF) are readable. 10. The Stratospheric Aerosol and Gas Experiment (SAGE) data format. 11. HDF-EOS including NASA Scatterometer data. MEXCDF Now obsolete interface that was developed for MATLAB-4. Use the NetCDF Toolbox for MATLAB-5 instead. MexEPS PMEL has developed a MATLAB interface, MexEPS, which supports several netCDF file conventions, including those adopted by PMEL. Many styles of time axes are supported and time manipulation routines ease the use of the time axis in MATLAB. The MexEPS package supports the following data formats: * reading, writing and editing netCDF files; * reading and writing Classic EPIC files * reading formatted ASCII files It includes: * VARIABLE, AXIS, ATTRIBUTE manipulation routines * TIME manipulation o TIME enters MATLAB as YYMMDDhhmmss.fff o Can be converted to netCDF udunits time convention (e.g. days since 1990-01-01 00:00:00) * MATLAB help and example scripts using MexEPS * ASCII2MAT mexFunction, which reads a formatted ASCII file into MATLAB as a matrix The MexEPS package is freely available in PMEL's anonymous ftp directory ftp://ftp.pmel.noaa.gov/eps/mexeps/ If you have any questions or comments, please contact the author, Willa Zhu (willa@pmel.noaa.gov) or Nancy Soreide (nns@pmel.noaa.gov). ncBrowse Donald Denbo of NOAA's Pacific Marine Environmental Laboratory has developed and made available ncBrowse, a Java application (JDK1.2) that provides flexible, interactive graphical displays of data and attributes from a wide range of netCDF data file conventions. Features * Designed to work with arbitrary netCDF files. * Browses file using the EPIC and COARDS conventions. * Provides a "tree" view of the netCDF file. * Handles character variables. * Handles dimensions without an associated variable. * Uses sgt graphics to perform 1 and 2 dimensional cuts through data. * Save to file single variable as a "cdl" text file. * InstallAnywhere scripts for UNIX, Win32, and MacOS. * Currently uses Java 2 and Swing. Requirements ncBrowse will run on any UNIX or Windows machine with a Java 2 (JDK1.2) virtual machine installed. Automated installation scripts are available for Windows and UNIX. Additional information on ncBrowse and download instructions are available at http://www.epic.noaa.gov/java/ncBrowse. Questions and suggestions should be directed to <dwd@pmel.noaa.gov>. If you have problems reading a netCDF file with ncBrowse, please send him a copy of the file and he'll get ncBrowse to read it! NCO NCO (netCDF operators) is a package of command line operators that work on generic netCDF or HDF4 files: * ncatted - attribute editor * ncdiff - differencer * ncea - ensemble averager * ncecat - ensemble concatenator * ncflint - file interpolator * ncks - kitchen sink (extract, cut, paste, print data) * ncra - running averager * ncrcat - record concatenator * ncrename - renamer * ncwa - weighted averager All operators may now be DODS clients. DODS enables network transparent data access to any DODS server. Thus DODS-enabled NCO can operate on remote files accessible through any DODS server without transferring the files. Only the required data (e.g., the variable or hyperslab specified) are transferred. The source code is freely available from the NCO home page, as is the NCO User's Guide. For more information, contact the author, Charlie Zender. ncview Ncview is a visual browser for netCDF files. Typically you would use ncview to get a quick and easy, push-button look at your netCDF files. You can view simple movies of the data, view along various dimensions, take a look at the actual data values, change color maps, invert the data, etc. It runs on UNIX platforms under X11, R4 or higher. For more information, check out the README file; you can also see a representative screen image (GIF, 66K) of ncview in action. The source may be downloaded from ftp://cirrus.ucsd.edu/pub/ncview/. For more information, please contact the author, David W. Pierce at dpierce@ucsd.edu. NetCDF File Calculator and Data Editor The netCDF calculator and data editor is part of the EPIC package, described above. Algebraic manipulations available under the netCDF calculator include arithmetic operations (addition, subtraction, multiplication and division), exponentiation, log functions, square root, and some additional functions such as differentiation, integration, regridding and removing the mean value. In addition to the built-in functions, the calculator also allows user written routines for manipulation of data. The netCDF calculator also provides the ability to extract a subset of the EPIC System Data sets by specifying limits in any or all of the four dimensions (x,y,z,time) or (i,j,k,l). The netCDF calculator includes an interactive data-editing function for one dimensional data sets. This displays the data and provides for replacement of individual points or a range of data points by linear interpolation or by typing in a replacement value. Data sets generated by the calculator data manipulation or data editing functions can be plotted with the standard PPLUS plotting commands and can also be written out as data files in any of the EPIC System formats (including netCDF). The netCDF calculator uses an expression language, much like C: although there are several control-flow statements, most statements such as assignments are expressions whose value is disregarded. For example, the assignment operator "=" assigns the value of its right operand to its left operand, and yields the value, so multiple assignments work. The calculator knows about four different data types: scalar (double precision floating point), string, slab (a specification for a four dimensional hyper-slab), and fields (a sub-sampled region of a four dimensional data set). The syntax for each of the four types are similar, however, not all operations are valid for all data types. The netCDF calculator discussed here is a simple programmable interpreter for floating point, string and field expressions. It has been extensively modified from hoc (The UNIX Programming Environment, Kernighan and Pike, Chapter 8). It has C-style control flow, function definition and the usual numerical built-in functions. The netCDF calculator has been developed using lex, a lexical analyzer, and yacc, a parser generator. This allows a systematic and consistent syntax to be implemented easily. Netcdf to HDF converter A NetCDF to HDF converter (Power Macintosh or Windows 95/NT) is available free from Fortner Software. This utility converts netCDF files to the HDF format so that datasets, their dimension scales and any attributes can be viewed with Fortner's free HDF Browser. Links to download the converter are available from the HDF Browser page. NetCDF Toolbox for MATLAB-5 The NetCDF Toolbox for MATLAB-5 combines netCDF-3 with MATLAB-5 to form an interface that uses MATLAB operator-syntax for arithmetic, logical, and subscripting operations on netCDF entities. This toolbox greatly extends and supersedes the now obsolete MEXCDF interface that was developed for MATLAB-4. In the NetCDF Toolbox interface, dimensions, variables, and attributes are represented by MATLAB objects that know how to do arithmetic on subscripted arrays. These objects are referred to by name rather than by ID, so the resulting MATLAB code is concise and comprehensible. An example that creates a new netCDF file, stores some data, and recalls the data illustrates use of the NetCDF Toolbox. The NetCDF Toolbox greatly simplifies interactions with netCDF files from within MATLAB, because the syntax is based on operators and MATLAB indexing. The NetCDF Toolbox also includes a NetCDF File Browser. For more information, contact Dr. Charles R. Denham, U.S. Geological Survey. PolyPaint+ PolyPaint+ is an interactive scientific visualization tool that displays complex structures within three-dimensional data fields. It provides both color shaded-surface display and simple volumetric rendering in either index or true color. For shaded surface rendering, the PolyPaint+ routines first compute the polygon set that describes a desired surface within the 3D data volume. These polygons are then rendered as continuously shaded surfaces. PolyPaint+ contains a wide variety of options that control lighting, viewing, and shading. Objects rendered volumetrically may be viewed along with shaded surfaces. Additional data sets can be overlaid on shaded surfaces by color coding the data according to a specified color ramp. 3D visualizations can be viewed in stereo for added depth perspective. Currently supported 3D visualizations are the following: * Shaded isosurface * Transparent contour shells or isosurfaces at varying levels * Volumetric or density plot * Planes * Contour ribbons * Topographic surface from 2D geographic data sets 3D data volumes may be sliced in the X, Y, or Z plane using an interactive cutting plane. A cross section of the data volume can be viewed in a 2D window as a 2D contour plot, a vector plot, a raster image or a combination of these options superimposed. Map outlines can be used as a background for 2D cross section plots of geographic data. All data is projected according to the coordinates specified by the user for the cross section window. The user interface provides direct manipulation tools for specifying the eye position, center of view, light sources, and color ramps. Subsetting of data can be done easily by selecting the data by index or geographic coordinate. On-line contextual help provides easy access to more detail about the software. Tutorials which range from very simple visualizations to complex combinations of data sets provide the user with a quick learning tool. Currently PolyPaint+ accepts only data which is in the NetCDF file format. A file conversion utility which converts from raw binary data to netCDf is a part of the application. PolyPaint+ is a joint effort of the University of Colorado and NCAR (National Center for Atmospheric Research) funded by the NASA AISRP program. A beta version of PolyPaint+ is currently available free of charge using FTP or for a nominal fee which would cover tape distribution. A license agreement must be signed in order to use it. You may order by... * TELEPHONE : 303-492-7289 (Margi Klemp) : 303-497-8159 (Bill Boyd) * U.S. MAIL : Margi Klemp University of Colorado / LASP 1234 Innovation Dr. Boulder, CO 80303 USA * E-MAIL : margi@aries.colorado.edu Python interfaces Python is an interpreted, object-oriented language that is supported on a wide range of hardware and operating systems. Python information and sources can be obtained from http://www.python.org/. There are now at least two netCDF interfaces for Python. The package from Konrad Hinsen has been integrated into his ScientificPython package. Bill Noon (noon@snow.cit.cornell.edu) has implemented another netCDF Python module that allows easy creation, access, and browsing of netCDF data. The bindings also use the udunits library to do unit conversions. More information and source for Noon's Python netCDF module are available from http://snow.cit.cornell.edu/noon/ncmodule.html. Tcl/Tk interface Dan Schmitt has developed cdftcl, a Tcl/Tk interface for netCDF. It allows the use of "wildcards" (*) or ranges (1-4) in the subscript notation, and use of name references instead of variable IDs. Contact dan@computer.org for more information. SciAn SciAn is a scientific visualization package developed at the Supercomputer Computations Research Institute at Florida State University. More information about SciAn is available from the URL http://www.scri.fsu.edu/~lyons/scian/. SciAn brings together the power of 3-dimensional scientific visualization and movie making with the ease of use and familiarity of object-oriented drawing packages. SciAn makes it very easy to apply visualization to new data by minimizing the number of decisions a researcher needs to make before seeing the first image on the screen. Once there is an image to work with, the researcher can modify the visualization to bring out details in the data using a wide variety of controls. SciAn can show any number of visualizations on the screen at one time. The viewpoint of different visualizations can be linked, enabling easy comparison of data from observation and simulation. Complete movie scenes can be made by adding a few lines to a SciAn generated script. SciAn can operate a laser videodisc recorder automatically or save images to files for recording later. SciAn produces isosurface, color mesh, line contour, trace, arrow, ball & stick, point cloud, and numeric display visualizations. It can work with fields defined over structured or nonstructured grids and geometric data in several formats, including NCSA's Hierarchical Data Format, NetCDF, and Protein Data Bank formats. SciAn is available, with full documentation, in electronic form over the network free of charge. For more information on SciAn, send electronic mail to: scian-info@scri.fsu.edu or write Supercomputer Computations Research Institute, Florida State University, Tallahassee, Florida, 32306-4052. SciAn requires: * a Silicon Graphics IRIS 4D series or IBM RISC System/6000 workstation with GL graphics library * a Z-buffer * ANSI-compliant C Desirable but not required are * an Alpha buffer * double buffering * FORTRAN and external libraries for more features VisAD VisAD is a Java class library for interactive and collaborative visualization and analysis of numerical data. It combines: * The use of pure Java for platform independence and to support data sharing and real-time collaboration among geographically distributed users. Support for distributed computing is integrated at the lowest levels of the system using Java RMI distributed objects. * A general mathematical data model that can be adapted to virtually any numerical data, that supports data sharing among different users, different data sources and different scientific disciplines, and that provides transparent access to data independent of storage format and location (i.e., memory, disk or remote). The data model has been adapted to netCDF, FITS, HDF-EOS, McIDAS, Vis5D, GIF and JPEG file formats. * A general display model that supports interactive 3-D, data fusion, multiple data views, direct manipulation, collaboration, and virtual reality. The display model has been adapted to Java3D and Java2D and used in an ImmersaDesk virtual reality display. * Data analysis and computation integrated with visualization to support computational steering and other complex interaction modes. * Support for two distinct communities: developers who create domain- specific systems based on VisAD, and users of those domain-specific systems. VisAD is designed to support a wide variety of user interfaces, ranging from simple data browser applets to complex applications that allow groups of scientists to collaboratively develop data analysis algorithms. * Developer extensibility in as many ways as possible. VisAD was written by programmers at the SSEC Visualization Project at the University of Wisconsin-Madison Space Science and Engineering Center, and the Unidata Program Office. WebWinds WebWinds is a free Java-based science visualization and analysis package. In addition to several new analysis tools, the current fourth beta version does automatic scripting. This allows 1. a user to rapidly and automatically create and store a session, either for his own use, or for use by a collaborator on another machine; 2. a data provider to automatically create a specialized analysis environment which can be downloaded (as a small script file) along with a dataset from a Website; and 3. realtime collaboration or sharing of sessions over (even low-bandwidth) networks, including the Internet. This scripting requires no knowledge of the scripting language syntax. Several sample script files are included with the distribution. In addition, this version contains a capability to geo-reference some data and to read ASCII data in tabular format. Also new is the ability to output data in numerical form (e.g. NetCDF) and a context sensitive, integrated help system. As with earlier versions, data in several different formats, including NetCDF, can be read in easily from your local machine or from the Web. In addition, most data can be subset or subsampled on load, making it possible to visualize very large multidimensional and/or multispectral datasets. The package includes several step-by-step examples. Installation of the software (including Java) on the PC or Mac is a process requiring one file to be downloaded and opened. If you need help getting started, a remote tutorial is available once you've downloaded the package. WebWinds is 'point and click' rather than language driven and it runs well on Unix, Windows (95/98/NT) and Mac platforms. It currently requires JDK 1.1. To download a copy of this release, go to http://webwinds.jpl.nasa.gov. Xmgr Xmgr (also known as ACE/gr) is a 2D plotting tool for the X window system. It uses a Motif-based interface, and runs on practically any version of Unix. It can read a 1-dimensional variable from a netCDF or HDF file and plot it against another 1-dimensional variable from the same file. A few of the other features are: * User defined scaling, tick marks, labels, symbols, line styles, colors. * Batch mode for unattended plotting. * Read and write parameters used during a session. * Regressions, splines, running averages, DFT/FFT, cross/auto-correlation, ... * Support for dynamic module loading. * Hardcopy support for PostScript, HP-GL, FrameMaker and InterLeaf formats. While ACE/gr has a convenient point-and-click interface, most parameter settings and operations are available through a command line interface. For more information, see the User Guide. Zebra Zebra (formerly named Zeb) is a system for data ingest, storage, integration and display, designed to operate in both real time and postprocessing modes. Zebra was developed by Jonathan Corbet and others in NCAR's Research Data Program. Zebra's primary use is for the superpositioning of observational data sets (such as those collected by satellite, radar, mesonet and aircraft) and analysis products (such as model results, dual-Doppler synthesis or algorithm output). Data may be overlaid on a variety of display types, including constant altitude planes, vertical cross-sections, X-Y graphs, Skew-T plots and time-height profiles. The fields for display, color tables, contour intervals and various other display options are defined using an icon based user-interface. This highly flexible system allows scientific investigators to interactively superimpose and highlight diverse data sets; thus aiding data interpretation. Data handling capabilities permit external analysis programs to be easily linked with display and data storage processes. The data store accepts incoming data, stores it on disk, and makes it available to processes which need it. An application library is available for data handling. The library functions allow data storage, retrieval and queries using a single applications interface, regardless of the data's source and organization. NetCDF data that conforms to Zebra conventions is supported by this interface. Zebra is currently available to the university research community through the NCAR/ATD Research Data Program. Email requests to rdp-support@atd.ucar.edu. More information is on the web page http://www.atd.ucar.edu/rdp/zebra.html. ------------------------------------------------------------------ User-Contributed Software Unidata makes available a separate catalog (http://www.unidata.ucar.edu/packages/netcdf/contrib.html) to a directory (ftp://ftp.unidata.ucar.edu/pub/netcdf/contrib/) of freely available, user-contributed software and documentation related to the netCDF library. This software may be retrieved by anonymous FTP. We haven't necessarily used or tested this software; we make it available "as is". The criteria for inclusion in the netcdf/contrib/ directory of user-contributed software are: * General usefulness to a significant part of the netCDF community * Small size * Infrequent need for updates * Free availability ------------------------------------------------------------------ AVS AVS (Application Visualization System) is a visualization application software and development environment. An AVS module has been written that allows multi-dimensional netCDF data sets to read into AVS as uniform or rectilinear field files. The AVS user can point and click to specify the name of the variable in the selected netCDF file, as well as selecting the hyperslab. If 1D coordinate variables exist (a variable that has the same name as a dimension) then the coordinate variable will be used to specify the coordinates of resulting rectilinear field file. If no coordinate variable exists, then the resulting field file will be uniform. Once in AVS, there are hundreds of analysis and display modules available for image processing, isosurface rendering, arbitrary slicing, alpha blending, streamline and vorticity calculation, particle advection, etc. AVS runs on many different platforms (Stardent, DEC, Cray, Convex, E and S, SET, Sun, IBM, SGI, HP, FPS and WaveTracer), and it has a flexible data model capable of handling multidimensional data on non-Cartesian grids. The module source code and documentation is available from the International AVS Center, in the ftp://testavs.ncsc.org/avs/AVS5/Module_Src/data_input/read_netcdf/ directory. See also the information on DDI for another way to use netCDF data with AVS. Environmental WorkBench SuperComputer Systems Engineering and Services Company (SSESCO) has developed the Environmental WorkBench (EWB), an easy to use visualization and analysis application targeted at environmental data. The EWB currently has numerous users in the fields of meteorological research, air quality work, and groundwater remediation. EWB system features include: * Random access file structure using the netCDF-based public domain MeRAF file system with support for gridded, discrete (non-grid-based observation), and particle types * Support for geo-referenced or Cartesian coordinate systems * Object oriented Graphical User Interface (GUI) that is very easy to use * Tools for converting model and observational data sets and data writers to netCDF * Interactive rotation/translation of scenes in 3D space * Time sequencing controls to step forward/backward, animate sequentially, or go to a chosen time step; including multiple asynchronous or non-uniform time steps * Interactive slicers to select cross sections through 3D data sets * Display operators available on the slices, including o Contour lines with selectable contour levels o Color shading by data value with variable transparency level o Arrow and streamline representation for vector quantities o Positional reference lines at user selected intervals o Color coded shapes at each grid node * Multiple 3D isosurfaces at selected parameters and values with variable transparency * Display of particle positions with coloring by type, height, and source * Display of discrete data using colored spheres and labels for scalar data and arrows for vectors (with arrowheads or meteorological style) * Multiple user definable color maps to which isosurface and colored field shading may be separately assigned * On screen annotation for generation of report ready figures * Image export in any of the common image formats (gif, tiff, encapsulated postscript, etc.) * Graceful handling of missing or bad data values by all the graphics rendering routines * Automatic data synchronization to allow automatic screen updating as new data arrives in real-time from a model or set of sensors * Two and three dimensional interpolation from scattered observations to a grid, using the Natural Neighbor Method. This robust volume based method yields results far superior to distance weighting schemes. Systems currently supported include Win95, WinNT, OS/2, IBM RS/6000, Silicon Graphics, HP and SUN workstations. SSESCO has implemented a meta-file layer on top of the netCDF library, called MeRAF. It handles multiple netCDF files as well as automatic max-min calculations, time-varying gridded, particle, and discrete data, logical groupings for discrete data, and an overall simplified and flexible interface for storing scientific data. MeRAF is being used by the DOE at the Hanford-Meteorological Site for observational data and will be used for their weather-modeling. IDL Interface IDL (Interactive Data Language) is a scientific computing environment that combines mathematics, advanced data visualization, scientific graphics, and a graphical user interface toolkit to analyze and visualize scientific data. Designed for use by scientists and scientific application developers, IDL's array-oriented, fourth-generation programming language allows you to prototype and develop complete applications. IDL now supports data in netCDF format. As an example, here is how to read data from a netCDF variable named GP in a file named "data/aprin.nc" into an IDL variable named gp using the IDL language: id = ncdf_open('data/april.nc') ncdf_varget,id, ncdf_varid( id, 'GP'), gp Now you can visualize the data in the gp variable in a large variety of ways and use it in other computations in IDL. You can FTP a demo version of IDL, including the netCDF interface, by following the instructions in pub/idl/README available via anonymous FTP from gateway.rsinc.com or boulder.colorado.edu. Other software packages that use or interoperate with IDL to access netCDF data includes ARGOS, CIDS Tools, DDI, HIPHOP, Hyperslab OPerator Suite (HOPS), and Noesys. InterFormat InterFormat is a medical image format conversion program with both Motif and character interfaces. InterFormat can automatically identify and convert most popular medical image formats and write output files in many standard medical image formats, or in formats such as netCDF that are suitable for input to leading scientific visualization packages. InterFormat runs on UNIX workstations; a version for OpenVMS is also available. A separate external module for IBM Data Explorer is available for use in IBM Data Explorer's Visual Program Editor. For more details about the formats handled, program features, and pricing, see the Radio-Logic web site at <http://www.radio-logic.com>. IRIS Explorer Module The Atmospheric and Oceanic Sciences Group at the National Center for Supercomputing Applications (NCSA) and the Mesoscale Dynamics and Precipitation Branch at NASA-Goddard Space Flight Center have developed the NCSA PATHFINDER module set for IRIS Explorer. Two of the modules, ReadDFG (to output Grids), and ReadDF (to output Lattices) are capable of reading from NCSA HDF files, MFHDF/3.3 files, and Unidata netCDF files. A user-friendly interface provides control and information about the contents of the files. For ReadDF, the format translation is handled transparently. Up to five unique lattices may be generated from the file (as these files can contain multiple data fields) using a single module. A variety of dimensionalities and data types are supported also. Multiple variables may be combined in a single lattice to generate vector data. All three Explorer coordinate systems are supported. With ReadDFG, user selected variables from the file are output in up to five PATHFINDER grids. Each grid can consist of scalar data from one variable or vector data from multiple variables. Coordinate information from the file is also included in the grids. Any number of dimensions in any of the Explorer coordinate types are supported. For more information on the NCSA PATHFINDER project and other available modules, visit the WWW/Mosaic PATHFINDER Home Page at http://redrock.ncsa.uiuc.edu/PATHFINDER/pathrel2/top/top.html The ReadDF module may be downloaded either via the WWW server or anonymous ftp at redrock.ncsa.uiuc.edu in the /pub/PATHFINDER directory. For more information please send email to: pathfinder@redrock.ncsa.uiuc.edu See also the information on DDI for another way to use netCDF data with IRIS Explorer. MATLAB MATLAB is an integrated technical computing environment that combines numeric computation, advanced graphics and visualization, and a high-level programming language. Several freely-available software packages that implement a MATLAB/netCDF interface are available: NetCDF Toolbox for MATLAB-5, MexEPS, the CSIRO MATLAB/netCDF interface and fanmat. NCAR Graphics The Scientific Visualization Group of the NCAR Scientific Computing Division has developed the NCAR Command Language (NCL) for interactive data manipulation and plot specification. This language supports a project to create, from existing utilities, a scientific visualization environment that provides a means of reading and writing data, a means of manipulating that data, and a means of visually analyzing the data interactively. NCL is intended to provide easy and intuitive access to datasets and allow users to explore and process their data prior to visualization. Since datasets often come in a variety of data formats, grid sizes, grid resolutions, and units, very different datasets often need to be combined, compared, and used at the same time. Currently, specialized applications must be developed to read individual datasets and transform them into a form that is compatible with other datasets being used, as well as with the graphics package being used. NCL allows different datasets, in different storage formats, to be imported into one uniform and consistent data manipulation environment. The primary data format used internally by NCL is the netCDF data format. NCL doesn't place any restrictions or conventions on the organization of input netCDF files. NCL is a complete programming language that provides flexibility and configurability. In NCL the primary data type is the data file record. A data file record stores one or more variables, dimension information, coordinate variable information and attribute information as one NCL object. A binary file can be read in, dimension names, variable names, attributes and coordinate variables can be assigned to it using NCL language constructs and the resulting file record can be written to any of the currently supported formats, including netCDF, without writing a single line of source code. The NCL language also provides the ability to specify configuration parameters for visualizations of data. These descriptions can be stored and used as user defaults and reused as plot specifications. The function set of NCL contains built-in data processing and mathematical functions and can be extended by the user to provide custom data processing techniques, as well as custom data ingestion. Contact Ethan Alpert, the NCAR Interactive project coordinator, at ethan@ncar.ucar.edu for more information. Noesys Noesys, developed by Fortner Software, is an environment for desktop science data access and visualization. Available for both Windows and Power Macintosh platforms, Noesys allows users to access, process, organize and visualize large amounts of technical data. Noesys can be used to: * Access and organize complex technical data * Export data objects to text and binary * View and edit large multidimensional data sets (up to 7D) in a spreadsheet-like environment * Manipulate and process data using IDLŽ, the Interactive Data Language, from Research Systems, Inc. * Interactively visualize column, matrix, and volumetric data sets * Image global datasets as various map projections * Create various projections from partial data or partial projections from global data (Windows only) * View and Edit HDF-EOS grid object data * Subset datasets and data tables with a GUI dialog * Change and save the number format of datasets and data table fields * Drag and Drop HDF objects between files to organize or subset files * Attach text annotations directly to the data file * Add new data objects to files and create hierarchical groups * Edit or create new color palettes * Generate publication-quality graphics for data presentation Noesys 2.0 has an interface to IDLŽ, allowing data to move back and forth between Noesys and IDL with the click of a mouse. Noesys includes the visual data analysis tools, Transform, T3D and Plot, for menu driven plotting, rendering, and image analysis. Noesys can import HDF, HDF-EOS, netCDF, ASCII, Binary, DTED, GeoTIFF, SDTS, TIFF, PICT, and BMP files, create annotations, macros, images, projections and color palettes specific to the data and save it the result as an HDF file. Noesys also includes an HDF-EOS Grid Editor. Noesys runs on Windows 95/98 & NT and Power Macintosh OS. More details and information about ordering Noesys are available from <http://www.fortner.com/>. PPLUS Plot-Plus (PPLUS) is a general purpose scientific graphics package, which is used in several PMEL applications. It will read most standard ascii or binary files, as well as netCDF file format, which used by the TOGA-TAO Project and the EPIC system for management display and analysis. PPLUS is an interactive, command driven, scientific graphics package which includes features such as Mercator projection, Polar Stereographic projection, color or gray scale area-fill contour plotting, and support for many devices: X-windows, PostScript, HP, Tektronix, and others. This powerful and flexible package recognizes netCDF data format, and it can extract axis lables and graph titles from the data files. The user can customize a plots, or combine several plots into a composite. Plots are of publication quality. The PPLUS graphics package is used for all the TAO workstation displays, including the animations. The animations are created by generating a PPLUS plot for each frame, transforming the PPLUS metacode files into hdf format with the PPLUS m2hdf filter, and then displaying the resulting bit maps as an animation with the XDataSlice utility, which is freely available on Internet from the National Center for Supercomputing Applications, at anonymous@ftp.ncsa.uiuc.edu (141.142.20.50). There is also a new m2gif utility which produces GIF files from PPLUS metacode files. PPLUS is supported for most Unix systems and for VAX/VMS, and is in use at many oceanographic institutes in the US (e.g., (PMEL, Harvard, WHOI, Scripps, NCAR, NASA, University of Rhode Island, University of Oregon, Texas A&M...) and also internationally (Japan, Germany, Australia, Korea...). Examples of PPLUS graphics are any of the graphs in the Web pages at: * http://www.pmel.noaa.gov/epic/home.html * http://www.pmel.noaa.gov/toga-tao/home.html * http://www.pmel.noaa.gov/toga-tao/realtime.html Plot Plus is now available at no charge. It does require licensing on a per computer basis, but the license is at no cost. For more information about licensing, see http://www.halcyon.com/www2/dwd/; source and documentation are available via anonymous FTP from ftp://ftp.halcyon.com/pub/users/dwd/pplus1_2g.tar.gz and ftp://ftp.halcyon.com/pub/users/dwd/ppldoc.tar.gz. Email: plot_plus@halcyon.com Postal mail: c/o Donald Denbo 2138 N 186th St Shoreline, WA 98133 Fax and Voice: (206) 366-0624 PV-Wave PV-Wave is a software environment from Visual Numerics for solving problems requiring the application of graphics, mathematics, numerics and statistics to data and equations. PV-WAVE uses a fourth generation language (4GL) that analyzes and displays data as you enter commands. PV-WAVE includes integrated graphics, numerics, data I/O, and data management. The latest version of PV-Wave supports data access in numerous formats, including netCDF. See also the information on DDI for another way to use netCDF data with PV-Wave. Slicer Dicer Slicer Dicer is a volumetric data visualization tool from Visualogic, currently available for Windows (95 and NT) and under development for other platforms. The Slicer Dicer Web site includes a complete list of features, an on-line user's guide, and examples of Slicer Dicer output. Visualizations features include: * Perspective view of data rendered on interactively selected orthogonal slices, oblique slices, blocks (arbitrary rectilinear sub-volumes), cutouts, isosurfaces, and projected volumes (projected maximum, minimum, maximum absolute, or minimum absolute). * Optional annotations: caption, axes ticks and labels (default "pretty" ticks, or override to place ticks where you want them), color legend, data-cube outline. * Animation modes: slices, space, time (any parametric dimension), transparency, oblique slice orientation, rotation. Built-in animation viewer supports speed and image size controls, single-step, forward, backward, loop, and back-and-forth modes. * Select color scale from 25+ built in color tables, or import from palette file. Any data level or range of levels can be painted with an arbitrary color. * Any data level or range of levels can be rendered as either opaque or transparent. VISAGE and Decimate VISAGE (VISualization, Animation, and Graphics Environment) is a turnkey 3D visualization system developed at General Electric Corporate Research and Development, (Schroeder, WJ et al, "VISAGE: An Object-Oriented Scientific Visualization System", Proceedings of Visualization `92 Conference). VISAGE is designed to interface with a wide variety of data, and uses netCDF as the preferred format. VISAGE is used at GE Corporate R & D, GE Aircraft Engine, GE Canada, GE Power Generation, as well as ETH Zurich, Switzerland, MQS In Chieti, Italy, and Rensselaer Polytechnic Institute in Troy, New York. GE has another application called "Decimate" that does polygon reduction/decimation (Schroeder,WJ et al, "Decimation of Triangle Meshes", Proceedings of SIGGRAPH `92). This application uses netCDF as a preferred format. Decimate is currently licensed to Cyberware, Inc., makers of 3D laser digitizing hardware. Decimate is currently bundled with the scanners, and will soon be available as a commercial product. WXP WXP is a software package developed at Purdue University in the Department of Earth and Atmospheric Sciences. It is intended to be an general purpose weather visualization tool for current and archived meteorological data. The products available with this server are derived from data obtained from the National Weather Service and the University of Wisconsin. WXP decodes broadcast weather data and model outputs into WXP-specific netCDF files, and provides analysis and display application programs for manipulating and displaying the data in those files. Universities must be licensed by Unidata and Purdue to obtain the WXP software. For information on obtaining a WXP license, contact support@unidata.ucar.edu. ------------------------------------------------------------------