in reply to Re^2: Math::GSL::SparseMatrix is broken if installed on latest 5.32.1.1 "Strawberry Perl PDL edition", whom to report this issue to?
in thread Math::GSL::SparseMatrix is broken if installed on latest 5.32.1.1 "Strawberry Perl PDL edition", whom to report this issue to?

I messed operator precedence, and so result looks silly and not trustworthy

Oh, no worries - that happens. (I know ;-)
For me, irrespective of the values assigned in the script, both gsl-2.6 and gsl-2.7.1 produce the same results.
That would suggest that the problem lies with the recent versions of the gsl library.
But, of course, the way I built Math-GSL-0.43 against gsl-2.7.1 (along with the test failures) doesn't inspire complete confidence in it ;-(

Playing around with it a bit, I find there's something (very strangely) buggy for the index 1 + (1 << 32), with both gsl-2.6 and gsl-2.7.1.
Have a fiddle with this, and you'll see what I mean: 
use strict;
use warnings;
use feature 'say';
use Alien::GSL;
use Math::GSL;
use Math::GSL::SparseMatrix ':all';

my $m = gsl_spmatrix_alloc( 1, 1 );

my $v;

#$v = 3 + (1 << 32); # no problem with this value
#$v = 2 + (1 << 32); # no problem with this value
#$v = 0 + (1 << 32); # no problem with this value
$v = 1 + (1 << 32); # blows up, but only if
                    # gsl_spmatrix_get($m, $v, 0)
                    # is called. 

die if gsl_spmatrix_set( $m, 1, 0, 1.5 );
say gsl_spmatrix_get($m, 1, 0);
say gsl_spmatrix_nnz( $m );
die if gsl_spmatrix_set( $m, $v, 0, 1.75 );
say gsl_spmatrix_get($m, $v, 0); # comment out to avoid blow up
                                  # when $v is 1 + (1 << 32).
                                  # But still gives wrong result
                                  # (for that value only).
say gsl_spmatrix_nnz( $m );

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The first thing to try is to run that as a C program and see if the same issue arises.
If not, then it's an issue with Math::GSL.
It's getting late over here ... something for tomorrow.

Cheers,
Rob
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Re^4: Math::GSL::SparseMatrix is broken if installed on latest 5.32.1.1 "Strawberry Perl PDL edition", whom to report this issue to?
by syphilis (Archbishop) on Nov 11, 2022 at 05:25 UTC
    ... something for tomorrow.

    It's apparently a problem with the gsl library: 
    /*
This file: gsl_spmatrix.c
Modify the following "-I..." and "-L..." arguments accordingly.

Using the gsl-2.6 library that ships with Strawberry Perl 5.32.1-PDL, 
+build with:
gcc -o gsl_spmatrix.exe gsl_spmatrix.c -ID:/sp/_64/sp-5.32.1-PDL/c/inc
+lude -LD:/sp/_64/sp-5.32.1-PDL/c/lib -lgsl -lgslcblas -lm

Then execute gsl_spmatrix.exe

Using the gsl-2.7.1 library provided by Alien, build with:
gcc -o gsl_spmatrix.exe gsl_spmatrix.c -ID:/sp/_64/sp-5.32.1/perl/site
+/lib/auto/share/dist/Alien-GSL/include -LD:/sp/_64/sp-5.32.1/perl/sit
+e/lib/auto/share/dist/Alien-GSL/lib -lgsl -lgslcblas -lm

Then execute gsl_spmatrix.exe
*/
#include <stdio.h>
#include <stdlib.h>
#include <gsl/gsl_spmatrix.h>

int main(void) {
 size_t v = 1;
 v <<= 32;
 v += 1;
 printf("size of size_t is %d bytes\n", sizeof(size_t));
 gsl_spmatrix *m = gsl_spmatrix_alloc(1,1);
 gsl_spmatrix_set( m, 1, 0, 1.5 );
 printf("1: got: %f\n", gsl_spmatrix_get( m, 1, 0));
 printf("1: nnz: %d\n", gsl_spmatrix_nnz( m ));
 gsl_spmatrix_set( m, v, 0, 1.75 );
 if (v >= m->size1) printf("will be reported as 'out of range'\n");
 printf("2: got: %f\n", gsl_spmatrix_get( m, v, 0 ));
 printf("2: nnz: %d\n", gsl_spmatrix_nnz( m ));
 return 0;
}


/*
As is, the built executable outputs (for both gsl-2.6 and gsl-2.7.1):

D:\C>gsl_spmatrix.exe
size of _size_t is 8 bytes
1: got: 1.500000
1: nnz: 1
will be reported as 'out of range'
gsl: getset_source.c:27: ERROR: first index out of range
Default GSL error handler invoked.

But if the line "v += 1;" is changed to "v += 2" or to "v += 3" or to 
+"v += 0" then the output is:

D:\C>gsl_spmatrix.exe
size of _size_t is 8 bytes
1: got: 1.500000
1: nnz: 1
2: got: 1.750000
2: nnz: 2
*/

    [download]
    I haven't yet reached an understanding of the problem.
    I think it should be reported to the gsl developers unless that has already been done.

    Cheers,
    Rob
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      Did you compile it from shell, created with portableshell.bat of Strawberry Perl 5.32.1-PDL? If I'm not using this shell, then gsl_spmatrix.exe complains it can't find libgsl-25__.dll, which would be in PATH created with portableshell.bat. I'm confused about this "25", does it mean anything? Should it be "26", i.e. is it "clean and correct" GSL 2.6 which ships with PDL-SP?

      Using "gsl-2.7.1 library provided by Alien", there's no such complaint. I can only add, that "v += 1;" is not special. If 1st setter sets at index 2, then "v += 2;" leads to "out of range". They both set the same element. If two setters set different values, and 1st getter gets value after that, then it retrieves value set by 2nd setter. 1st value was overwritten.

      I haven't reported yet, would it be better to write to both GSL and Math::GSL queues? (Math::GSL ignores whatever Alien::GSL has built) Or reporting to Math::GSL is enough, they'll see further?

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        Did you compile it from shell, created with portableshell.bat of Strawberry Perl 5.32.1-PDL?

        Yes. 
        ----------------------------------------------
 Welcome to Strawberry Perl PDL Edition!
 * URL - http://strawberryperl.com + http://pdl.perl.org
 * to launch perl script run:      perl c:\my\scripts\pdl-test.pl
 * to start PDL console run:       pdl2
 * to update PDL run:              cpanm PDL
 * to install extra module run:    cpanm PDL::Any::Module
          or if previous fails:    ppm PDL::Any::Module
 * or you can use dev tools like:  gcc, g++, gfortran, gmake
 * see README.TXT for more info
----------------------------------------------
Perl executable: D:\sp\_64\sp-5.32.1-PDL\perl\bin\perl.exe
Perl version   : 5.32.1 / MSWin32-x64-multi-thread
PDL version    : 2.025

D:\sp\_64\sp-5.32.1-PDL>cd \C

D:\C>gcc -o gsl_spmatrix.exe gsl_spmatrix.c -ID:/sp/_64/sp-5.32.1-PDL/
+c/include -LD:/sp/_64/sp-5.32.1-PDL/c/lib -lgsl -lgslcblas -lm

D:\C>gsl_spmatrix.exe
size of _size_t is 8 bytes
1: got: 1.500000
1: nnz: 1
will be reported as 'out of range'
gsl: getset_source.c:27: ERROR: first index out of range
Default GSL error handler invoked.

D:\C>

        [download]

        I'm confused about this "25", does it mean anything?

        I think that's ok. I'm quite used to seeing dll numberings that don't make any sense.
        My SP-5.32.1-PDL certainly ships with c/bin/libgsl-25__.dll and I'm not seeing anything unusual happening (apart from the buggy behaviour.)

        Using "gsl-2.7.1 library provided by Alien", there's no such complaint.

        Are you sure that it's actually using gsl-2.7.1 ? Here's an improved C program that will output that info: 
        #include <stdio.h>
#include <stdlib.h>
#include <gsl/gsl_spmatrix.h>
#include <gsl/gsl_version.h>

int main(void) {
 size_t v = 1;
 v <<= 32;
 v += 1;
 printf("gsl header version : %s\n", GSL_VERSION);
 printf("gsl library version: %s\n", gsl_version);
 printf("size of _size_t is %d bytes\n", sizeof(size_t));
 if(v == 1) printf("WTF\n");
 gsl_spmatrix *m = gsl_spmatrix_alloc(1,1);
 gsl_spmatrix_set( m, 1, 0, 1.5 );
 printf("1: got: %f\n", gsl_spmatrix_get( m, 1, 0));
 printf("1: nnz: %d\n", gsl_spmatrix_nnz( m ));
 gsl_spmatrix_set( m, v, 0, 1.75 );
 if (v >= m->size1) printf("will be reported as 'out of range'\n");
 printf("2: got: %f\n", gsl_spmatrix_get( m, v, 0 ));
 printf("2: nnz: %d\n", gsl_spmatrix_nnz( m ));
 return 0;
}

        [download]


        If 1st setter sets at index 2, then "v += 2;" leads to "out of range". They both set the same element

        I don't understand this.
        Are you claiming that v + 2 == 2 ?
        While that might be deemed true on a 32-bit system, it's not the case when sizeof(size_t) is 8.
        Could you provide the perl -V output of your Strawberry-5.32.1-PDL. (Maybe I've missed something significant.) 
        D:\C>perl -le "$x = (1 << 32) + 2; print $x; print 'WTF' if $x == 2;"
4294967298

        [download]

        Cheers,
        Rob
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