# SEED

Portability Subroutine: Changes the starting point of the pseudorandom number generator.

## Module

USE IFPORT

CALL SEED (iseed)

iseed | (Input) INTEGER(4). Starting point for RANDOM.

SEED uses iseed to establish the starting point of the pseudorandom number generator. A given seed always produces the same sequence of values from RANDOM.

If SEED is not called before the first call to RANDOM, RANDOM always begins with a seed value of one. If a program must have a different pseudorandom sequence each time it runs, pass the constant RND$TIMESEED (defined in `IFPORT.F90`) to the SEED routine before the first call to RANDOM.

This routine is not thread-safe.

## Example

     USE IFPORT
     REAL myrand
     CALL SEED(7531)
     CALL RANDOM(myrand)

Parent topic: S

## See Also

RANDOM
RANDOM_INIT
RANDOM_SEED
RANDOM_NUMBER