Hi all!
while I need annulus (or torus) neighbor to some of my work I added easily it to neighbors (grass 65 delev) module. Because I do not won't to create a fork of that module I put it on that url:
http://www.staff.amu.edu.pl/~jarekj/r.neighbors2.tar.gz
Annulus neighbor is a circular neighbor but with exuding nearest neighborhood defined by inner radius.
Maybe someones will find this useful.
regards
Jarek
Hi Jarek and r.neighbor maintenators,
I suggest put a flag on r.neighbor for annulus (torus), so in future versions the module will be always update.
Just a suggestion.
Jarek, congrats.
cheers
milton
2010/11/15 Jasiewicz Jarosław <jarekj@amu.edu.pl>
Hi all!
while I need annulus (or torus) neighbor to some of my work I added easily it to neighbors (grass 65 delev) module. Because I do not won’t to create a fork of that module I put it on that url:
http://www.staff.amu.edu.pl/~jarekj/r.neighbors2.tar.gz
Annulus neighbor is a circular neighbor but with exuding nearest neighborhood defined by inner radius.
Maybe someones will find this useful.
regards
Jarek
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Jasiewicz Jarosław wrote:
while I need annulus (or torus) neighbor to some of my work I added
easily it to neighbors (grass 65 delev) module. Because I do not won't
to create a fork of that module I put it on that url:
If you need neighbourhood shape other than a square or circle, use the
weights= option.
Masks can be created using NumPy; e.g.
from numpy import *
r = 7 # outer radius
r0 = 3 # inner radius
d = sqrt(fromfunction(lambda x, y: (x-r)**2 + (y-r)**2, (2*r+1, 2*r+1)))
m = logical_and(d >= r0, d <= r)
savetxt('weights', m, fmt = '%d')
Or for smooth edges:
from numpy import *
r = 7 # outer radius
r0 = 3 # inner radius
d = sqrt(fromfunction(lambda x, y: (x-r)**2 + (y-r)**2, (2*r+1, 2*r+1)))
m = minimum(1, maximum(0, (r-r0)/2 - abs(d - (r+r0)/2)))
savetxt('weights', m, fmt = '% .3f')
If you only need a mask (weights of 0 or 1), you can use anything
which can outupt PGM files (use the P2 "text" format and cut off the
header).
--
Glynn Clements <glynn@gclements.plus.com>
Glynn Clements pisze:
Jasiewicz Jaros³aw wrote:
while I need annulus (or torus) neighbor to some of my work I added easily it to neighbors (grass 65 delev) module. Because I do not won't to create a fork of that module I put it on that url:
If you need neighbourhood shape other than a square or circle, use the
weights= option.Masks can be created using NumPy; e.g.
from numpy import *
r = 7 # outer radius
r0 = 3 # inner radius
d = sqrt(fromfunction(lambda x, y: (x-r)**2 + (y-r)**2, (2*r+1, 2*r+1)))
m = logical_and(d >= r0, d <= r)
savetxt('weights', m, fmt = '%d')Or for smooth edges:
from numpy import *
r = 7 # outer radius
r0 = 3 # inner radius
d = sqrt(fromfunction(lambda x, y: (x-r)**2 + (y-r)**2, (2*r+1, 2*r+1)))
m = minimum(1, maximum(0, (r-r0)/2 - abs(d - (r+r0)/2)))
savetxt('weights', m, fmt = '% .3f')If you only need a mask (weights of 0 or 1), you can use anything
which can outupt PGM files (use the P2 "text" format and cut off the
header).
yes, but for me modification of C code was little simpler than this.
cheers
Jarek
Milton Cezar Ribeiro wrote:
I suggest put a flag on r.neighbor for annulus (torus), so in future
versions the module will be always update.
A flag alone isn't sufficient; it would also need an option for the
inner radius.
In general, we try to avoid adding options for features which can be
accomplished by a separate program. The selection= option was only
added because the alternative (applying the mask afterwards) could be
significantly slower.
--
Glynn Clements <glynn@gclements.plus.com>