Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl Monk, Perl Meditation

Re^3: Speeding up point-in-polygon

by explorer (Chaplain)
on Jul 24, 2006 at 10:39 UTC ( #563231=note: print w/replies, xml ) Need Help??

in reply to Re^2: Speeding up point-in-polygon
in thread Speeding up point-in-polygon

If you can reduce the data to cartesian coords. and the entire zone can reside into RAM, PDL is the faster solution.

Example: If $zone is a piddle of bytes with an 1 where the point's coords, you can retrieve the coords of points into polygon's box limits with:
$area = $zone->slice("$xmin:$xmax,$ymin:$ymax"); $coord_points = wichND( $area );
Now, you will have the coords of all points into the $area:
@x_coords = list $coord_points->slice("(0),:"); @y_coords = list $coord_points->slice("(1),:");
This is the fast clipping method if you can reduce the data universe to cartesian coords.

And PDL is a C compiled library.

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://563231]
and all is quiet...

How do I use this? | Other CB clients
Other Users?
Others scrutinizing the Monastery: (7)
As of 2018-06-18 14:35 GMT
Find Nodes?
    Voting Booth?
    Should cpanminus be part of the standard Perl release?

    Results (110 votes). Check out past polls.