RAND — Real pseudo-random number

Description

RAND(FLAG) returns a pseudo-random number from a uniform distribution between 0 and 1. If FLAG is 0, the next number in the current sequence is returned; if FLAG is 1, the generator is restarted by CALL SRAND(0); if FLAG has any other value, it is used as a new seed with SRAND.

This intrinsic routine is provided for backwards compatibility with GNU Fortran 77. It implements a simple modulo generator as provided by g77. For new code, one should consider the use of RANDOM_NUMBER as it implements a superior algorithm.

Syntax

RESULT = RAND(I)

Arguments

I Shall be a scalar INTEGER of kind 4.

Return value

The return value is of REAL type and the default kind.

Example



program test_rand

  integer,parameter :: seed = 86456



  call srand(seed)

  print *, rand(), rand(), rand(), rand()

  print *, rand(seed), rand(), rand(), rand()

end program test_rand

Standard

GNU extension

Class

Function