On 28/01/17 18:29, Paul Lantos wrote:
I am trying to figure out how to randomly jitter points within an
overlying polygon structure.
I can easily jitter the points themselves, but I would like this to
be constrained by the boundaries of polygons containing the points.
This isn't for visualiza
Thanks, will take a look!
Paul
From: obrlsoi...@gmail.com [mailto:obrlsoi...@gmail.com]
Sent: Saturday, January 28, 2017 1:03 AM
To: Paul Lantos ; r-sig-geo@r-project.org; obrl_soil
Subject: RE: [R-sig-Geo] jitter within polygon
Maybe try this sampler -
https://gist.github.com/obrl-soil
Ok, thanks. It's for about 100,000 points within thousands of polygons, and
they need to 1) remain within a polygon and 2) retain original attribute data.
Could be a challenging workflow...
Paul
-Original Message-
From: Baldwin, Jim -FS [mailto:jbald...@fs.fed.us]
Sent: Saturday, Januar
Point-in-polygon routines are pretty fast and straightforward to use. If it's
about reducing computing time, then maybe for "irregular" polygons it would be
easier to stratify the points into two groups: those points whose jittering
would not go outside the polygon and those that might and onl
Maybe try this sampler -
https://gist.github.com/obrl-soil/839b192da46978351733483421db22f8
You’d want to run it multiple times and cycle through the outputs, if I’m
interpreting your request correctly.
Cheers
@obrl_soil
From: Paul Lantos
Sent: Saturday, 28 January 2017 3:30 PM
To: r-sig-geo@
Thanks, Jim. There isn't a way to specify the polygons a priori in order to
constrain the jittering?
Paul
-Original Message-
From: Baldwin, Jim -FS [mailto:jbald...@fs.fed.us]
Sent: Saturday, January 28, 2017 12:47 AM
To: Paul Lantos ; r-sig-geo@r-project.org
Subject: RE: jitter within
Sounds like you need a "point-in-polygon" routine to determine if the jittered
point is still within the polygon.
R has several such routines. Here are two:
pnt.in.poly in the SDMTools package
point.in.polygon in the sp package
Mathematica has several options, too.
Jim
-Original Me
