use strict;
use warnings;
use PDL;
use PDL::GSL::RNG qw(ran_bivariate_gaussian_pdf);

my @insert = sample_data();
my ($XSIZE, $YSIZE) = (300, 300);
my ($xcoord, $ycoord, $weight) = pdl(\@insert) # xyw nweights
  ->slice(",*$XSIZE,*$YSIZE,")                 # xyw nx ny nweights
  ->using(0..2);                               # nx ny nweights
my $xbase = xvals($XSIZE)->slice(",*$YSIZE");  # nx ny
my $ybase = xvals($YSIZE)->slice("*$XSIZE,");  # nx ny

$| = 1; print "Generating GIF frame ";

# replace Imager::Heatmap::insert_datas
my @hms = map {
  my $h = (
    $weight * ran_bivariate_gaussian_pdf(
      $xcoord-$xbase, $ycoord-$ybase, $_, $_, 0
    )                                           # nx ny nweights
  )->mv(-1,0)->sumover;                         # nx ny
  print ".";
  $h;
} 1..90;
my $all_vals = pdl(\@hms);                      # dims: nx ny frame

# broadcasting version of Imager::Heatmap::draw
use PDL::Graphics::ColorSpace;
my $frame_max = $all_vals->clump(0,1)->maxover; # dims: nxy frame, then frame
$all_vals /= $frame_max->slice("*1,*1,");       #       nx ny frame
my $hue = (1 - $all_vals)*240;
my $d = cat($hue, pdl(1), pdl(1))->mv(-1,0);    #       hsv nx ny frame
my $all_hms = (hsv_to_rgb($d) * 255)->byte;     #       rgb nx ny frame
# Imager::write_multi
unlink($_), $all_hms->wmpeg($_) for 'heatmapb.gif';
print "\n";

sub sample_data {
  my @insert = ();
  while (<DATA>) {
    chomp; push @insert, [ split /\s+/ ]
  }
  return @insert
}

__DATA__
...