# f90_kind: KIND Number Parameters Module

f90_kind: KIND Number Parameters Module

# f90_kind: KIND Number Parameters Module

## 1 Name

f90_kind — Module providing useful KIND number parameters

USE F90_KIND

## 3 Synopsis

Parameters
ASCII, BYTE, DOUBLE, INT16, INT32, INT64, INT8, JIS, LOGICAL64, QUAD, REAL128, REAL32, REAL64, REAL64x2, SINGLE, TWOBYTE, UCS2, UCS4, WORD.

## 4 Parameter Description

  INTEGER,PARAMETER :: SINGLE

For REAL and COMPLEX, selects the default real or default complex kind; this is equivalent to leaving the KIND selector off entirely.

  INTEGER,PARAMETER :: DOUBLE

Selects the double precision real kind; this is equivalent to declaring REAL entities using the DOUBLE PRECISION type specifier, to declaring COMPLEX entities using COMPLEX(KIND(0d0)), and to using the exponent letter D on literal constants.

  INTEGER,PARAMETER :: QUAD

REAL/COMPLEX kind selector for real and complex types with approximately twice the precision of DOUBLE. This might not be available on some systems; on a system without this type, the value of this parameter will be negative.

  INTEGER,PARAMETER :: REAL32

REAL/COMPLEX kind selector for real and complex types that are represented using 32-bit floating-point numbers.

  INTEGER,PARAMETER :: REAL64

REAL/COMPLEX kind selector for real and complex types that are represented using 64-bit floating-point numbers.

  INTEGER,PARAMETER :: REAL64x2

REAL/COMPLEX kind selector for real and complex types that are represented using “double-double” floating-point numbers. A double-double floating-point number consists of two 64-bit values, one of which is at least DIGITS(1._REAL64) smaller than the other; this has almost twice the precision of REAL64 (except when near zero), but a smaller exponent range.

This type is not available on all systems; on a system without this type, the value of this parameter is −1.

  INTEGER,PARAMETER :: REAL128


REAL/COMPLEX kind selector for real and complex types that are represented using 128-bit floating-point numbers. This will select a “true 128-bit” floating-point type if one is available, and if not it will select a “double-double” floating-point type if that is available; if no 128-bit floating-point type is available the value of this parameter is -1.

  INTEGER,PARAMETER :: INT8

INTEGER kind selector for integer types with at least 8 bits of precision.

  INTEGER,PARAMETER :: INT16

INTEGER kind selector for integer types with at least 16 bits of precision.

  INTEGER,PARAMETER :: INT32

INTEGER kind selector for integer types with at least 32 bits of precision.

  INTEGER,PARAMETER :: INT64

INTEGER kind selector for integer types with at least 64 bits of precision.

  INTEGER,PARAMETER :: BYTE

LOGICAL kind selector for logical types occupying only one byte of memory.

  INTEGER,PARAMETER :: TWOBYTE

LOGICAL kind selector for logical types occupying the same space as INTEGER(INT16) entities.

  INTEGER,PARAMETER :: WORD

LOGICAL kind selector for a 32-bit logical type.

  INTEGER,PARAMETER :: LOGICAL64

LOGICAL kind selector for a 64-bit logical type.
  INTEGER,PARAMETER :: ASCII

CHARACTER kind selector for the ASCII character set.
  INTEGER,PARAMETER :: JIS

CHARACTER kind selector for the JIS X 0213:2004 character set.
  INTEGER,PARAMETER :: UCS2

CHARACTER kind selector for the UCS-2 (Unicode) character set.
  INTEGER,PARAMETER :: UCS4

CHARACTER kind selector for the UCS-4 (ISO 10646) character set.

## 5 Notes

The source code for this module can be found in the NAG Fortran runtime library directory (on Unix this is usually ‘/usr/local/lib/NAG_Fortran’ or ‘/opt/NAG_Fortran/lib’, and on Windows it is usually ‘C:\Program Files\NAG\EFBuilderPro\NAG_Fortran\lib’).