[GRASS-user] Python scripts using rules

GRASS GRASS user
1

Greetings

I’m doing a processing that requires setting rules such as : IF band1> 1 output=5 if band<=1 ouput= 3 and if band2>5 output=7. How can I do this in a Python script in order to be “almost automatic”?

Thanks

Best regards
Luisa

2

Hi,

2010/6/22 Luisa Peña <luisapena1979@gmail.com>:

Greetings
I'm doing a processing that requires setting rules such as : IF band1> 1
output=5 if band<=1 ouput= 3 and if band2>5 output=7. How can I do this in a
Python script in order to be "almost automatic"?

if band1 > 1:
   output = 5
else:
   output = 3

if band2 > 5:
   output = 7

Martin

--
Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa

3

Hi Martin
Maybe I was not clear enough. this is a procedding to be done over each pixel. Can I apply this sort of code to a pixel based analysis?

2010/6/22 Martin Landa <landa.martin@gmail.com>

Hi,

2010/6/22 Luisa Peña <luisapena1979@gmail.com>:

Greetings
I’m doing a processing that requires setting rules such as : IF band1> 1
output=5 if band<=1 ouput= 3 and if band2>5 output=7. How can I do this in a
Python script in order to be “almost automatic”?

if band1 > 1:
output = 5
else:
output = 3

if band2 > 5:
output = 7

Martin

–
Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa

4

Hi,

2010/6/22 Luisa Peña <luisapena1979@gmail.com>:

Maybe I was not clear enough. this is a procedding to be done over each
pixel. Can I apply this sort of code to a pixel based analysis?

mapcalc() from grass.script.raster [1] or try ctypes interface from trunk.

Martin

[1] http://download.osgeo.org/grass/grass7_progman/namespacepython_1_1raster.html#a0f8268995af8d19e6b86e1f67295aaaf

--
Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa

5

Hi Martin
Thanks
You mean like using an expression, for mapcalc, based on ifs right? Is this interface available for GRASS6.4? If so, is there an example of usage?

And about the ctypes interface? What is it? can it work on GRASS6.4.0 RC6?

Thanks
Luisa

2010/6/22 Martin Landa <landa.martin@gmail.com>

Hi,

2010/6/22 Luisa Peña <luisapena1979@gmail.com>:

Maybe I was not clear enough. this is a procedding to be done over each
pixel. Can I apply this sort of code to a pixel based analysis?

mapcalc() from grass.script.raster [1] or try ctypes interface from trunk.

Martin

[1] http://download.osgeo.org/grass/grass7_progman/namespacepython_1_1raster.html#a0f8268995af8d19e6b86e1f67295aaaf

–

Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa

6

Hi Martin
Thanks
You mean like using an expression, for mapcalc, based on ifs right? Is this interface available for GRASS6.4? If so, is there an example of usage?

And about the ctypes interface? What is it? can it work on GRASS6.4.0 RC6?

Thanks
Luisa

2010/6/22 Martin Landa <landa.martin@gmail.com>

Hi,

2010/6/22 Luisa Peña <luisapena1979@gmail.com>:

Maybe I was not clear enough. this is a procedding to be done over each
pixel. Can I apply this sort of code to a pixel based analysis?

mapcalc() from grass.script.raster [1] or try ctypes interface from trunk.

Martin

[1] http://download.osgeo.org/grass/grass7_progman/namespacepython_1_1raster.html#a0f8268995af8d19e6b86e1f67295aaaf

–

Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa