Re: rand() function on Windows systems

in reply to rand() function on Windows systems

If you install Inline::C you can access the MS CRT rand() & srand() and wrap them in your own wrappers.

The following code produces 56 (which is the same as I get from Perl's built-ins for 5.10). You might try it on your system and see how it compares:

#! perl -slw
use strict;
use Inline C => Config => BUILD_NOISY => 1;
use Inline C => <<'END_C',  NAME => 'junk1_IC', CLEAN_AFTER_BUILD => 0
+;

int osrand( SV *seed ) {
    srand( (unsigned int)SvIV( seed ) );
    return 1;
}
double orand( SV *max ) {
    return (double)rand() / 32767.0 * SvNV( max );
}
END_C

osrand( 555 );
print int orand( 1000 );
[download]

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Comment on Re: rand() function on Windows systems Download Code

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Re^2: rand() function on Windows systems by bakiperl (Beadle) on Dec 30, 2016 at 21:38 UTC
Yes. That did the trick. Thank you BrowserUk	[reply]
Re^3: rand() function on Windows systems (pure Perl) by BrowserUk (Patriarch) on Dec 30, 2016 at 21:57 UTC
Just for completeness, this pure perl version should also work: `{ my $seed; sub ppSrand{ $seed = int( $_[ 0 ] & 32767 ); } sub ppRand{ my $max = shift // 1; $seed = ( $seed * 214013 + 2531011 ); return ( ( $seed >> 16 ) & 32767 ) / 32768 * $max; ## Amend +ed per post below. } } ppSrand( 555 ); print int ppRand( 1000 );` [download] With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". The enemy of (IT) success is complexity. In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l]
Re^4: rand() function on Windows systems (pure Perl) by BillKSmith (Monsignor) on Dec 31, 2016 at 05:03 UTC
Thanks, BrowserUK. I have a low priority project which has been on hold for several years awaiting a solution to the problem described by the OP. Somehow, I overlooked the possibility of writing a generator. (The quality of the sequence is not an issue.) Your solution seems perfect! Bill	[reply]
Re^4: rand() function on Windows systems (pure Perl) by bakiperl (Beadle) on Dec 30, 2016 at 23:23 UTC
Wow! This is even better. Thank you.	[reply]
Re^5: rand() function on Windows systems (pure Perl)(Correction) by BrowserUk (Patriarch) on Jan 01, 2017 at 19:12 UTC
Re^6: rand() function on Windows systems (pure Perl)(Correction) by bakiperl (Beadle) on Jan 01, 2017 at 23:09 UTC
Re^4: rand() function on Windows systems (pure Perl) by stevieb (Canon) on Dec 31, 2016 at 00:08 UTC
That's very nice. I'm glad we have statistical analysts/mathematicians here.	[reply]
Re^5: rand() function on Windows systems (pure Perl) by bakiperl (Beadle) on Dec 31, 2016 at 02:59 UTC
Re^6: rand() function on Windows systems (pure Perl) by BrowserUk (Patriarch) on Dec 31, 2016 at 03:10 UTC
Some notes below your chosen depth have not been shown here
Re^5: rand() function on Windows systems (pure Perl) by BrowserUk (Patriarch) on Dec 31, 2016 at 01:15 UTC

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