Could you possibly work up a simple running script, with sample data, so we can see what format your data is in, and the dimensions of your piddles? It sounds to me my you are looking for "slices", to do the changes in place (efficiently), but I have no idea what your piddle looks like.

The cool thing about slices, is that whatever operation you perform on the slice, also occurs to the original piddle. 

#!/usr/bin/perl
use warnings;
use strict;
use PDL::LiteF;


my $x = sequence(25);  # Create a piddle of increasing value
print "$x\n";                

my $slice =  slice $x,'4:20:2';
print $slice;
print "\n";

$slice .= 0;
print $slice;
print "\n";

print $x;
print "\n";

for (1..100){
$slice ++;
print $x;
print "\n";
select(undef,undef,undef,.5);
}

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I'm not really a human, but I play one on earth. Cogito ergo sum a bum

In reply to Re: Hash-type lookup in PDL by zentara
in thread Hash-type lookup in PDL by andye

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