pygrass.modules.grid package

Submodules

pygrass.modules.grid.grid module

class pygrass.modules.grid.grid.GridModule(cmd, width=None, height=None, overlap=0, processes=None, split=False, debug=False, region=None, move=None, log=False, start_row=0, start_col=0, out_prefix=u'', mapset_prefix=None, *args, **kargs)

Bases: object

Run GRASS raster commands in a multiprocessing mode.

Parameters:

• cmd (str) – raster GRASS command, only command staring with r.* are valid.
• width (int) – width of the tile, in pixel
• height (int) – height of the tile, in pixel.
• overlap (int) – overlap between tiles, in pixel.
• processes – number of threads, default value is equal to the number of processor available.
• split (bool) – if True use r.tile to split all the inputs.
• mapset_prefix (str) – if specified created mapsets start with this prefix
• run (bool) – if False only instantiate the object
• args – give all the parameters to the command
• kargs – give all the parameters to the command

>>> grd = GridModule('r.slope.aspect',
...                  width=500, height=500, overlap=2,
...                  processes=None, split=False,
...                  elevation='elevation',
...                  slope='slope', aspect='aspect', overwrite=True)
>>> grd.run()

clean_location(location=None)

Remove all created mapsets.

Parameters:location (Location object) – a Location instance where we are running the analysis

define_mapset_inputs()

Add the mapset information to the input maps

get_works()

Return a list of tuble with the parameters for cmd_exe function

patch()

Patch the final results.

rm_tiles()

Remove all the tiles.

run(patch=True, clean=True)

Run the GRASS command

Parameters:

• patch (bool) – set False if you does not want to patch the results
• clean (bool) – set False if you does not want to remove all the stuff created by GridModule

split()

Split all the raster inputs using r.tile

pygrass.modules.grid.grid.cmd_exe(args)

Create a mapset, and execute a cmd inside.

Parameters:args (tuple) – is a tuple that contains several information see below Returns:None

The puple has to contain:

• bbox (dict): a dict with the region parameters (n, s, e, w, etc.) that we want to set before to apply the command.
• mapnames (dict): a dictionary to substitute the input if the domain has been splitted in several tiles.
• gisrc_src (str): path of the GISRC file from where we want to copy the groups.
• gisrc_dst (str): path of the GISRC file where the groups will be created.
• cmd (dict): a dictionary with all the parameter of a GRASS module.
• groups (list): a list of strings with the groups that we want to copy in the mapset.

pygrass.modules.grid.grid.copy_groups(groups, gisrc_src, gisrc_dst, region=None)

Copy group from one mapset to another, crop the raster to the region

Parameters:

• groups (list of strings) – a list of strings with the group that must be copied from a master to another.
• gisrc_src (str) – path of the GISRC file from where we want to copy the groups
• gisrc_dst (str) – path of the GISRC file where the groups will be created
• region (Region object or dictionary) – a region like object or a dictionary with the region parameters that will be used to crop the rasters of the groups

Returns:

None

pygrass.modules.grid.grid.copy_mapset(mapset, path)

Copy mapset to another place without copying raster and vector data.

Parameters:

• mapset (Mapset object) – a Mapset instance to copy
• path (str) – path where the new mapset must be copied

Returns:

the instance of the new Mapset.

>>> mset = Mapset()
>>> mset.name
'user1'
>>> import tempfile as tmp
>>> import os
>>> path = os.path.join(tmp.gettempdir(), 'my_loc', 'my_mset')
>>> copy_mapset(mset, path)
Mapset('user1')
>>> sorted(os.listdir(path))
[u'PERMANENT', u'user1']
>>> sorted(os.listdir(os.path.join(path, 'PERMANENT')))
[u'DEFAULT_WIND', u'PROJ_EPSG', u'PROJ_INFO', u'PROJ_UNITS', u'VAR', u'WIND']
>>> sorted(os.listdir(os.path.join(path, 'user1'))) 
[...u'SEARCH_PATH', u'VAR', u'WIND']
>>> import shutil
>>> shutil.rmtree(path)

pygrass.modules.grid.grid.copy_rasters(rasters, gisrc_src, gisrc_dst, region=None)

Copy rasters from one mapset to another, crop the raster to the region.

Parameters:

• rasters (list) – a list of strings with the raster map that must be copied from a master to another.
• gisrc_src (str) – path of the GISRC file from where we want to copy the groups
• gisrc_dst (str) – path of the GISRC file where the groups will be created
• region (Region object or dictionary) – a region like object or a dictionary with the region parameters that will be used to crop the rasters of the groups

Returns:

None

pygrass.modules.grid.grid.copy_special_mapset_files(path_src, path_dst)

Copy all the special GRASS files that are contained in a mapset to another mapset

Parameters:

• path_src (str) – the path to the original mapset
• path_dst (str) – the path to the new mapset

pygrass.modules.grid.grid.copy_vectors(vectors, gisrc_src, gisrc_dst)

Copy vectors from one mapset to another, crop the raster to the region.

Parameters:

• vectors (list) – a list of strings with the vector map that must be copied from a master to another.
• gisrc_src (str) – path of the GISRC file from where we want to copy the groups
• gisrc_dst (str) – path of the GISRC file where the groups will be created

Returns:

None

pygrass.modules.grid.grid.get_cmd(cmdd)

Transform a cmd dictionary to a list of parameters. It is useful to pickle a Module class and cnvert into a string that can be used with Popen(get_cmd(cmdd), shell=True).

Parameters:cmdd (dict) – a module dictionary with all the parameters

>>> slp = Module('r.slope.aspect',
...              elevation='ele', slope='slp', aspect='asp',
...              overwrite=True, run_=False)
>>> get_cmd(slp.get_dict())  
['r.slope.aspect', u'elevation=ele', u'format=degrees', ..., u'--o']

pygrass.modules.grid.grid.get_mapset(gisrc_src, gisrc_dst)

Get mapset from a GISRC source to a GISRC destination.

Parameters:

• gisrc_src (str) – path to the GISRC source
• gisrc_dst (str) – path to the GISRC destination

Returns:

a tuple with Mapset(src), Mapset(dst)

pygrass.modules.grid.grid.read_gisrc(gisrc)

Read a GISRC file and return a tuple with the mapset, location and gisdbase.

Parameters:gisrc (str) – the path to GISRC file Returns:a tuple with the mapset, location and gisdbase

>>> import os
>>> read_gisrc(os.environ['GISRC'])  
(u'user1', ...)

pygrass.modules.grid.grid.select(parms, ptype)

Select only a certain type of parameters.

Parameters:

• parms (DictType parameters) – a DictType parameter with inputs or outputs of a Module class
• ptype (str) – String define the type of parameter that we want to select, valid ptype are: ‘raster’, ‘vector’, ‘group’

Returns:

An iterator with the value of the parameter.

>>> slp = Module('r.slope.aspect',
...              elevation='ele', slope='slp', aspect='asp',
...              run_=False)
>>> for rast in select(slp.outputs, 'raster'):
...     print(rast)
...
slp
asp

pygrass.modules.grid.grid.set_region(region, gisrc_src, gisrc_dst, env)

Set a region into two different mapsets.

Parameters:

• region (Region object or dictionary) – a region like object or a dictionary with the region parameters that will be used to crop the rasters of the groups
• gisrc_src (str) – path of the GISRC file from where we want to copy the groups
• gisrc_dst (str) – path of the GISRC file where the groups will be created
• env –

Returns:

None

pygrass.modules.grid.patch module

Created on Tue Apr 2 18:57:42 2013

@author: pietro

pygrass.modules.grid.patch.get_start_end_index(bbox_list)

Convert a Bounding Box to a list of the index of column start, end, row start and end

Parameters:bbox_list (list of BBox object) – a list of BBox object to convert

pygrass.modules.grid.patch.rpatch_map(raster, mapset, mset_str, bbox_list, overwrite=False, start_row=0, start_col=0, prefix=u'')

Patch raster using a bounding box list to trim the raster.

Parameters:

• raster (str) – the name of output raster
• mapset (str) – the name of mapset to use
• mset_str (str) –
• bbox_list (list of BBox object) – a list of BBox object to convert
• overwrite (bool) – overwrite existing raster
• start_row (int) – the starting row of original raster
• start_col (int) – the starting column of original raster
• prefix (str) – the prefix of output raster

pygrass.modules.grid.patch.rpatch_row(rast, rasts, bboxes)

Patch a row of bound boxes.

Parameters:

• rast (Raster object) – a Raster object to write
• rasts (list of Raster object) – a list of Raster object to read
• bboxes (list of BBox object) – a list of BBox object

pygrass.modules.grid.split module

Created on Tue Apr 2 19:00:15 2013

@author: pietro

pygrass.modules.grid.split.get_bbox(reg, row, col, width, height, overlap)

Return a Bbox

Parameters:

• reg (Region object) – a Region object to split
• row (int) – the number of row
• col (int) – the number of row
• width (int) – the width of tiles
• height (int) – the width of tiles
• overlap (int) – the value of overlap between tiles

pygrass.modules.grid.split.get_overlap_region_tiles(region=None, width=100, height=100, overlap=0)

Get the Bbox of the overlapped region.

Parameters:

• region (Region object) – a Region object to split
• width (int) – the width of tiles
• height (int) – the width of tiles
• overlap (int) – the value of overlap between tiles

pygrass.modules.grid.split.split_region_tiles(region=None, width=100, height=100, overlap=0)

Spit a region into a list of Bbox.

Parameters:

• region (Region object) – a Region object to split
• width (int) – the width of tiles
• height (int) – the width of tiles
• overlap (int) – the value of overlap between tiles

>>> reg = Region()
>>> reg.north = 1350
>>> reg.south = 0
>>> reg.nsres = 1
>>> reg.east = 1500
>>> reg.west = 0
>>> reg.ewres = 1
>>> reg.cols
1500
>>> reg.rows
1350
>>> split_region_tiles(region=reg, width=1000, height=700, overlap=0) 
[[Bbox(1350.0, 650.0, 1000.0, 0.0), Bbox(1350.0, 650.0, 1500.0, 1000.0)],
 [Bbox(650.0, 0.0, 1000.0, 0.0), Bbox(650.0, 0.0, 1500.0, 1000.0)]]
>>> split_region_tiles(region=reg, width=1000, height=700, overlap=10) 
[[Bbox(1350.0, 640.0, 1010.0, 0.0), Bbox(1350.0, 640.0, 1500.0, 990.0)],
 [Bbox(660.0, 0.0, 1010.0, 0.0), Bbox(660.0, 0.0, 1500.0, 990.0)]]

Module contents