2.12 Explanation of Functions: DCL Character Functions

A group of functions concerning the handling of character codes used in GRPH1.

In GRPH1, not only normal ASCII characters, but also Greek letters and special characters can be used as well, (See Font Table in Section 8.1.2,8.1.3). To specify a character string for the text primitive, the characters on the keyboard can be inputted as they are. Characters that are not included in the keyboard, or those that are not properly displayed, are specified by giving the number (DCL character number) in the Font Table as an argument in the function subprogram CSGI.

The character function CSGI is equivalent to the FORTRAN CHAR function for computer systems using the ASCII code. However, in computer systems that use the ESCDI code, for example, the correct character cannot be displayed using a CHAR function. The function CSGI is used to specify a character uniquely in any code system. The inverse function, which returns a DCL character number from the given character, is the ISGC..

The CSGI is used, for example, when you write

cos alpha x

by first declaring

CHARACTER CSGI*1

then create the character string

'cos'//CSGI(152)//'x'

to hand over to the text primitive.

The group of functions listed here are system-dependent, so their source codes are stored under an independent directory named csgi , and not under sgpack.