Please open a bug ticket with a small attached program showing the problem
at https://sourceforge.net/p/pdl/bugs/
to track the issue. I'm fine with pushing a release with a fix. Craig?
Thanks,
Chris
On Mon, Jan 22, 2018 at 10:44 PM, Trevor Carey-Smith <
[email protected]> wrote:
> Chris,
>
> Your 'where' option works well, but not so much for multi-dimensional
> arrays. It's possible to use whereND, but it gets awfully convoluted having
> to reorder dimensions so that it threads over the required dimensions, e.g.
> for 2 dimensions something like this:
> $data = $data(:,which($data(1,:)>=0))->sever;
> becomes:
> $data = $data->transpose->whereND($data((1),:) >
> 0)->transpose->sever;
>
> I ended up sticking with my usage of which() and adding some tests to
> catch the singular dimension cases.
>
> Looking forward to a future release that might iron out this issue :-).
>
> Kind regards,
> Trevor
>
> -----Original Message-----
> From: Chris Marshall [mailto:[email protected]]
> Sent: Tuesday, 23 January 2018 3:56 p.m.
> To: Trevor Carey-Smith <[email protected]>
> Cc: perldl <[email protected]>
> Subject: Re: [Pdl-general] Slicing pdl with empty index variable
>
> Trevor-
>
> Did the where work around work or did you come up with a better solution?
>
> --Chris
>
> On 1/13/2018 12:53, Chris Marshall wrote:
> > If you skip the index part using where does it work?
> > E.g.,
> >
> > $a->where($a==0) .= 1;
> > $b = $b->where($b>0)->sever;
> >
> > --Chris
> >
> > On 1/12/2018 20:07, Trevor Carey-Smith wrote:
> >> Thanks Craig.
> >>
> >> In the interim, is there a better way to do the following:
> >>
> >> $a(which($a==0)).=1;
> >> $b = $b(which($b > 0))->sever;
> >>
> >> as now I'll have to replace all this sort of thing with something like:
> >>
> >> $tmp=which($a==0);
> >> if ($tmp->nelem > 0) { a($tmp) .= 1; }
> >>
> >> $tmp = which($b > 0);
> >> if ($tmp->nelem > 0) {
> >> $b = $b($tmp)->sever;
> >> } else {
> >> $b = pdl([ ]);
> >> }
> >>
> >> Cheers,
> >> Trevor
> >>
> >> ________________________________________
> >> From: Craig DeForest <[email protected]>
> >> Sent: Saturday, 13 January 2018 9:35 a.m.
> >> To: Trevor Carey-Smith
> >> Cc: Craig DeForest; [email protected]
> >> Subject: Re: [Pdl-general] Slicing pdl with empty index variable
> >>
> >> Hmmm. Looks like you've discovered a wart. Indexing pdl(1,2) with
> >> an Empty does the right thing and returns Empty. But indexing a
> >> scalar or a 1-D PDL with one element fails. I think it's because
> >> Empties are implemented under the hood as 1x0 PDLs (to distinguish
> >> them from Nulls, which have 0 in the first position).
> >>
> >>
> >>
> >>> On Jan 11, 2018, at 8:52 PM, Trevor Carey-Smith
> >>> <[email protected]> wrote:
> >>>
> >>> Hi,
> >>>
> >>> Sorry I've been out of the PDL loop for a long time, but have an old
> >>> script written in PDL that I use a lot. After a recent IT upgrade
> >>> here we have shifted to PDL v2.018 and I'm getting some behaviour
> >>> that is new from our previous install (2.4 in the old numbering
> >>> system???).
> >>>
> >>> The script uses some which() statements to create indexing vectors
> >>> to slice the original pdl. Normally when the which statement comes
> >>> back empty, the slice command returns an empty pdl itself. But if
> >>> the slicing dimension (regardless of the total number of dimensions)
> >>> of the original pdl is of length 1 bad things happen. Perhaps an
> >>> example is clearer:
> >>>
> >>> pdl> p $empty=pdl([])
> >>> Empty[0]
> >>> pdl> p $d2=pdl([1,2])
> >>> [1 2]
> >>> pdl> p $d2($empty)
> >>> Empty[0]
> >>> pdl> p $d1=pdl([1])
> >>> [1]
> >>> pdl> p $d1($empty)
> >>> Stringizing problem: slice: slice starts out of bounds in pos 0
> >>> (start is 1; source dim 0 runs 0 to 0). eval {...} called at
> >>> /scale_akl_persistent/filesets/opt_niwa/centos7-x86_64-skl_prelim/GC
> >>> C-4.8.5/Perl/5.24.1-GCC-4.8.5/lib/perl5/site_perl/5.24.1/x86_64-linu
> >>> x-thread-multi/PDL/Core.pm
> >>> line 2857
> >>> PDL::string(PDL=SCALAR(0x1053d10), undef, "") called at
> >>> /scale_akl_persistent/filesets/opt_niwa/centos7-x86_64-skl_prelim/GC
> >>> C-4.8.5/Perl/5.24.1-GCC-4.8.5/bin/perldl
> >>> line 402
> >>> main::p(PDL=SCALAR(0x1053d10)) called at (eval 151) line 4
> >>> main::__ANON__() called at
> >>> /scale_akl_persistent/filesets/opt_niwa/centos7-x86_64-skl_prelim/GC
> >>> C-4.8.5/Perl/5.24.1-GCC-4.8.5/bin/perldl
> >>> line 719
> >>> eval {...} called at
> >>> /scale_akl_persistent/filesets/opt_niwa/centos7-x86_64-skl_prelim/GC
> >>> C-4.8.5/Perl/5.24.1-GCC-4.8.5/bin/perldl
> >>> line 719
> >>> main::eval_and_report("p \$d1->slice(\$empty)\x{a}") called
> >>> at
> >>> /scale_akl_persistent/filesets/opt_niwa/centos7-x86_64-skl_prelim/GC
> >>> C-4.8.5/Perl/5.24.1-GCC-4.8.5/bin/perldl
> >>> line 655
> >>> main::process_input() called at
> >>> /scale_akl_persistent/filesets/opt_niwa/centos7-x86_64-skl_prelim/GC
> >>> C-4.8.5/Perl/5.24.1-GCC-4.8.5/bin/perldl
> >>> line 675
> >>> eval {...} called at
> >>> /scale_akl_persistent/filesets/opt_niwa/centos7-x86_64-skl_prelim/GC
> >>> C-4.8.5/Perl/5.24.1-GCC-4.8.5/bin/perldl
> >>> line 675
> >>> at
> >>> /scale_akl_persistent/filesets/opt_niwa/centos7-x86_64-skl_prelim/GC
> >>> C-4.8.5/Perl/5.24.1-GCC-4.8.5/lib/perl5/site_perl/5.24.1/x86_64-linu
> >>> x-thread-multi/PDL/Core.pm
> >>> line 2888, <STDIN> line 92.
> >>> PDL::string(PDL=SCALAR(0x1053d10), undef, "") called at
> >>> /scale_akl_persistent/filesets/opt_niwa/centos7-x86_64-skl_prelim/GC
> >>> C-4.8.5/Perl/5.24.1-GCC-4.8.5/bin/perldl
> >>> line 402
> >>> main::p(PDL=SCALAR(0x1053d10)) called at (eval 151) line 4
> >>> main::__ANON__() called at
> >>> /scale_akl_persistent/filesets/opt_niwa/centos7-x86_64-skl_prelim/GC
> >>> C-4.8.5/Perl/5.24.1-GCC-4.8.5/bin/perldl
> >>> line 719
> >>> eval {...} called at
> >>> /scale_akl_persistent/filesets/opt_niwa/centos7-x86_64-skl_prelim/GC
> >>> C-4.8.5/Perl/5.24.1-GCC-4.8.5/bin/perldl
> >>> line 719
> >>> main::eval_and_report("p \$d1->slice(\$empty)\x{a}") called
> >>> at
> >>> /scale_akl_persistent/filesets/opt_niwa/centos7-x86_64-skl_prelim/GC
> >>> C-4.8.5/Perl/5.24.1-GCC-4.8.5/bin/perldl
> >>> line 655
> >>> main::process_input() called at
> >>> /scale_akl_persistent/filesets/opt_niwa/centos7-x86_64-skl_prelim/GC
> >>> C-4.8.5/Perl/5.24.1-GCC-4.8.5/bin/perldl
> >>> line 675
> >>> eval {...} called at
> >>> /scale_akl_persistent/filesets/opt_niwa/centos7-x86_64-skl_prelim/GC
> >>> C-4.8.5/Perl/5.24.1-GCC-4.8.5/bin/perldl
> >>> line 675
> >>>
> >>> Can anyone shed any light on what's going on here??
> >>>
> >>> Thanks,
> >>> Trevor.
> >>>
> >>> --------------------------------------------------------------------
> >>> ----------
> >>>
> >>> Check out the vibrant tech community on one of the world's most
> >>> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
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> >>> pdl-general mailing list
> >>> [email protected]
> >>> https://lists.sourceforge.net/lists/listinfo/pdl-general
> >>>
> >>
> >> ---------------------------------------------------------------------
> >> ---------
> >>
> >> Check out the vibrant tech community on one of the world's most
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> >> https://lists.sourceforge.net/lists/listinfo/pdl-general
> >
>
>
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