Directives

RANDOMIZE

Set Random Key

Format

RANDOMIZE seed
 
Where:

seed

Numeric value or expression to be used as the seed by the random number generator.

Description

Use the RANDOMIZE directive to assign a seed to be used by the random number generator. PxPlus uses the given value to define the starting point for the random number generator (RND system variable). Use the RANDOMIZE directive to have PxPlus return a repeatable random sequence.

See Also

RND Random Number Generator
RND( ) Return Random Number

Example

In the following example, PxPlus will RANDOMIZE 1 or create a repeatable random sequence using 1 as the seed. Then, for instance, each time the number 2 is encountered in the loop below, it will generate 0.59859266:

for I=1 to 2
     randomize 1
     for J=1 to 5
          print rnd," ",
     next J
     print "END OF LOOP ",str(I)
next I

->run
0.11337858 0.59859266 0.81950925          0.76559375 0.5199119 END OF LOOP 1
0.11337858 0.59859266 0.81950925          0.76559375 0.5199119 END OF LOOP 2

In the following example, PxPlus will use a repeatable random sequence for indices; i.e. to create a repeatable number to use each time a particular index number is encountered:

0010 input "Enter random seed:",N
0020 randomize N
0030 open (31)"TESTFILE"
0040 for I=1 to 1000
0050 read (31,ind=int(rnd*100),err=0090)R$
0060 print rnd," ",R$," ",
0070 next I
0080 print "DONE"; close (31); stop
0090 …