Dear Monks,

I was suggested yesterday to try PDL, here's the built of the fractal structure (diagonal 4 out of 4x4 plan +=1): 

#!/usr/bin/perl -w
use strict;
use PDL;
use Algorithm::Loops qw(NestedLoops);

my $element = pdl ([1,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]);
my $tmp = pdl ($element);

my @depth = qw (2 3 4 5 6 7 8);
foreach my $depth (@depth) {

    my $same = pdl ($tmp);
    
    my $fractal = zeroes 4**$depth,4**$depth;
    
    NestedLoops([([0..3])x2],sub{
        my ($x,$y) = (@_);
        my ($a,$b) = ($x*(4**($depth-1)),$y*(4**($depth-1)));
        my ($c,$d) = ($a+((4**($depth-1))-1),$b+((4**($depth-1))-1));
        my $square = slice $fractal, "$a:$c,$b:$d";
        $square += $same;
        },);

    for my $coord (0..3) {
        my $a = $coord * (4**($depth-1));
        my $b = $a + ((4**($depth-1))-1);
        my $square = slice $fractal, "$a:$b,$a:$b";
        $square += 1;
        }
    
    $tmp = pdl ($fractal);
    $outFractal = $tmp;
    }

[download]
At level 6 and more: Out of memory! - but that was fast. So I see that building the structure isn't optimal memorywise, even with PDL.

Frank

In reply to Fractal structure: PDL, memory, time by FFRANK

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