dc_units Module Reference

Unit system processing module. More...

Data Types
type	units
interface	clear
interface	deallocate
interface	operator(*)
interface	operator(/)
interface	operator(+)

Functions/Subroutines
logical function, public	add_okay (u1, u2)

Detailed Description

Unit system processing module.

Author

Youhei SASAKI, Eizi TOYODA, Yasuhiro MORIKAWA

Copyright

Copyright (C) GFD Dennou Club, 2000-2026. All rights reserved.
License is BSD-2-Clause. see COPYRIGHT in detail

This module provides procedures for unit system processing. It includes a derived type UNITS for representing physical units and operators for unit arithmetic (multiplication, division, addition).

Operators and Procedures

Operator/Procedure	Description
assignment(=)	Build UNITS from string or convert to string
operator(*)	Multiply two UNITS
operator(/)	Divide two UNITS
operator(+)	Add two UNITS (with compatibility check)
clear	Initialize UNITS variable
deallocate	Deallocate UNITS variable
add_okay	Check if two UNITS are compatible for addition

Function/Subroutine Documentation

add_okay()

logical function, public dc_units::add_okay	(	type(units), intent(in)	u1,
		type(units), intent(in)	u2 )

Check if two UNITS are compatible for addition

Two units are compatible if they have the same dimensions (i.e., the same unit elements with the same powers).

Parameters

[in]	u1	First UNITS variable
[in]	u2	Second UNITS variable

Returns

.true. if compatible, .false. otherwise

Definition at line 307 of file dc_units.f90.

    type(UNITS), intent(in):: u1, u2
    type(UNITS):: x
    character(STRING):: debug
    call clear(x)
    x = u1 / u2
    debug = u1
    debug = u2
    debug = x
    if (x%nelems == 0) then
      result = .true.
    else if (all(abs(x%power(1:x%nelems)) < tiny(0.0_dp))) then
      result = .true.
    else
      result = .false.
    endif
    call deallocate(x)