Re: [GRASS-user] passing raster map to Python object
Hi Hamish, Thanks for your encourager's email. I started to play with numpy for other purposes, but I will give a look in deep for this. If I get success I will be happy report it here. bests milton 2009/8/12 Hamish hamis...@yahoo.com Milton Cezar Ribeiro wrote: I am building a simulation python code that read a raster maps on grass mapset. As my maps is not so large (512x512 pixels) I dump it on a text file (using r.out.ascii), after I read the text file on python, parse it using a function that I wrote, and after create a matrix-like object on Python. I would like to know if I can read my raster map on python wihout save it on external text file. Case yes, a short example are welcome. you might look at NumPy http://numpy.scipy.org/ + NumPtr python extension. NumPtr can be found in the swig/python/ dir in the grass source code. (also examples/m.distance + rasteraccess.py there) NumPy is also used by the wxGUI profile tool. SciPy is another thing to check out. please post back to the list with what you learn :) if you succeed maybe add a page to the grass wiki with steps? Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] passing raster map to Python object
Milton Cezar Ribeiro wrote: Thanks for your encourager's email. I started to play with numpy for other purposes, but I will give a look in deep for this. If I get success I will be happy report it here. it should work. one thing, be sure to translate NULL cells to numpy.nan, e.g. import numpy as np x = np.array([[1, 2, 3], [4, 5, 6]], np.float64) x array([[ 1., 2., 3.], [ 4., 5., 6.]]) x[0,1] 2.0 x[0,1] = np.nan x array([[ 1., nan, 3.], [ 4., 5., 6.]]) see swig/python/examples/rasteraccess.py for reading raster row by row. Hamish ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] passing raster map to Python object
Dear all, I am building a simulation python code that read a raster maps on grass mapset. As my maps is not so large (512x512 pixels) I dump it on a text file (using r.out.ascii), after I read the text file on python, parse it using a function that I wrote, and after create a matrix-like object on Python. I would like to know if I can read my raster map on python wihout save it on external text file. Case yes, a short example are welcome. cheers milton brazil=toronto ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
