Hello all!
How to write PDL efficient code for computing the moving average or
moving median?
For example, I want to use the median filter width of 33 pixels for data:
$x=sequence(1000);
$y=sin($x/10)+random($x)/10;
For data of little size I can create new piddle size of (33,nelem($y))
where each row contains a portion of data size of 33 which then I
include in "medover":
$med=&medianPDL($y,33);
sub medianPDL{
my $pdl=shift;
my $win=shift;
my $tmp=zeroes($win,nelem($pdl));
my $inds=yvals($tmp)-int($win/2)+xvals($tmp);
my $a=$inds->minimum;
$a->where($a>=0).=0;
$inds-=$a->dummy(0,$win);
my $b=$inds->maximum-$tmp->getdim(1)+1;
$b->where($b<0).=0;
$inds-=$b->dummy(0,$win);
return $pdl->index($inds)->medover;
}
________________________________
May be exists a more efficient way to compute the moving average or
moving median?
Yury
------------------------------------------------------------------------------
Site24x7 APM Insight: Get Deep Visibility into Application Performance
APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month
Monitor end-to-end web transactions and take corrective actions now
Troubleshoot faster and improve end-user experience. Signup Now!
http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140
_______________________________________________
pdl-general mailing list
pdl-general@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/pdl-general
