grass.pygrass.modules.grid package¶

class grass.pygrass.modules.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='', mapset_prefix=None, patch_backend=None, *args, **kargs)[source]¶

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
patch_backend (None or str) – “r.patch”, “RasterRow”, or None for for default
run (bool) – if False only instantiate the object
args – give all the parameters to the command
kargs – give all the parameters to the command

When patch_backend is None, the RasterRow method is used for patching the result. When patch_backend is “r.patch”, r.patch is used with nprocs=processes. r.patch can only be used when overlap is 0.

>>> 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()

Temporary mapsets created start with a generated prefix which is unique for each process (includes PID and node name). If more instances of this class are used in parallel from one process with the same module, a custom mapset_prefix needs to be provided.

clean_location(location=None)[source]¶

Remove all created mapsets.

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

define_mapset_inputs()[source]¶: Add the mapset information to the input maps

estimate_tile_size()[source]¶

Estimates tile width and height based on number of processes.

Keeps width and height if provided by user. If one dimension is provided the other is computed as the minimum number of tiles to keep all requested processes working (initially). If no dimensions are provided, tiling is 1 column x N rows which speeds up patching.

get_works()[source]¶: Return a list of tuples with the parameters for cmd_exe function

patch()[source]¶: Patch the final results.

rm_tiles()[source]¶: Remove all the tiles.

run(patch=True, clean=True)[source]¶

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()[source]¶: Split all the raster inputs using r.tile

Submodules¶

grass.pygrass.modules.grid.grid module¶

class grass.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='', mapset_prefix=None, patch_backend=None, *args, **kargs)[source]¶

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
patch_backend (None or str) – “r.patch”, “RasterRow”, or None for for default
run (bool) – if False only instantiate the object
args – give all the parameters to the command
kargs – give all the parameters to the command

When patch_backend is None, the RasterRow method is used for patching the result. When patch_backend is “r.patch”, r.patch is used with nprocs=processes. r.patch can only be used when overlap is 0.

>>> 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()

Temporary mapsets created start with a generated prefix which is unique for each process (includes PID and node name). If more instances of this class are used in parallel from one process with the same module, a custom mapset_prefix needs to be provided.

clean_location(location=None)[source]¶

Remove all created mapsets.

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

define_mapset_inputs()[source]¶: Add the mapset information to the input maps

estimate_tile_size()[source]¶

Estimates tile width and height based on number of processes.

Keeps width and height if provided by user. If one dimension is provided the other is computed as the minimum number of tiles to keep all requested processes working (initially). If no dimensions are provided, tiling is 1 column x N rows which speeds up patching.

get_works()[source]¶: Return a list of tuples with the parameters for cmd_exe function

patch()[source]¶: Patch the final results.

rm_tiles()[source]¶: Remove all the tiles.

run(patch=True, clean=True)[source]¶

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()[source]¶: Split all the raster inputs using r.tile

grass.pygrass.modules.grid.grid.cmd_exe(args)[source]¶

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 split 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.

grass.pygrass.modules.grid.grid.copy_groups(groups, gisrc_src, gisrc_dst, region=None)[source]¶

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

grass.pygrass.modules.grid.grid.copy_mapset(mapset, path)[source]¶

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.

>>> from grass.script.core import gisenv
>>> mname = gisenv()['MAPSET']
>>> mset = Mapset()
>>> mset.name == mname
True
>>> import tempfile as tmp
>>> import os
>>> path = os.path.join(tmp.gettempdir(), 'my_loc', 'my_mset')
>>> copy_mapset(mset, path)                           
Mapset(...)
>>> sorted(os.listdir(path))                          
[...'PERMANENT'...]
>>> sorted(os.listdir(os.path.join(path, 'PERMANENT')))
['DEFAULT_WIND', 'PROJ_INFO', 'PROJ_UNITS', 'VAR', 'WIND']
>>> sorted(os.listdir(os.path.join(path, mname)))   
[...'WIND'...]
>>> import shutil
>>> shutil.rmtree(path)

grass.pygrass.modules.grid.grid.copy_rasters(rasters, gisrc_src, gisrc_dst, region=None)[source]¶

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

grass.pygrass.modules.grid.grid.copy_special_mapset_files(path_src, path_dst)[source]¶

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

grass.pygrass.modules.grid.grid.copy_vectors(vectors, gisrc_src, gisrc_dst)[source]¶

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

grass.pygrass.modules.grid.grid.get_cmd(cmdd)[source]¶

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', 'elevation=ele', 'format=degrees', ..., '--o']

grass.pygrass.modules.grid.grid.get_mapset(gisrc_src, gisrc_dst)[source]¶

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)

grass.pygrass.modules.grid.grid.read_gisrc(gisrc)[source]¶

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
>>> from grass.script.core import gisenv
>>> genv = gisenv()
>>> (read_gisrc(os.environ['GISRC']) == (genv['MAPSET'],
...                                      genv['LOCATION_NAME'],
...                                      genv['GISDBASE']))
True

grass.pygrass.modules.grid.grid.select(parms, ptype)[source]¶

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

grass.pygrass.modules.grid.grid.set_region(region, gisrc_src, gisrc_dst, env)[source]¶

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

grass.pygrass.modules.grid.patch module¶

Created on Tue Apr 2 18:57:42 2013

@author: pietro

grass.pygrass.modules.grid.patch.get_start_end_index(bbox_list)[source]¶: Convert a Bounding Box to a list of the index of column start, end, row start and end :param bbox_list: a list of BBox object to convert :type bbox_list: list of BBox object

Deprecated since version 8.3.

grass.pygrass.modules.grid.patch.rpatch_map(raster, mapset, mset_str, bbox_list, overwrite=False, start_row=0, start_col=0, prefix='')[source]¶

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

grass.pygrass.modules.grid.patch.rpatch_map_r_patch_backend(raster, mset_str, bbox_list, overwrite=False, start_row=0, start_col=0, prefix='', processes=1)[source]¶

Patch raster using a r.patch. Only use with overlap=0. Will be faster than rpatch_map, since r.patch is parallelized.

Parameters

raster (str) – the name of output raster
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
processes (int) – number of parallel process for r.patch

grass.pygrass.modules.grid.patch.rpatch_row(rast, rasts, bboxes)[source]¶

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

grass.pygrass.modules.grid.split module¶

Created on Tue Apr 2 19:00:15 2013

@author: pietro

grass.pygrass.modules.grid.split.get_bbox(reg, row, col, width, height, overlap)[source]¶

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

grass.pygrass.modules.grid.split.get_overlap_region_tiles(region=None, width=100, height=100, overlap=0)[source]¶

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

grass.pygrass.modules.grid.split.get_tile_start_end_row_col(reg, row, col, width, height)[source]¶

Return a tile’s starting and ending row and col

Parameters

reg (Region object) – a Region object to split
row (int) – the number of tiles in a row
col (int) – the number of tiles in a col
width (int) – the width of tiles
height (int) – the width of tiles

grass.pygrass.modules.grid.split.split_region_in_overlapping_tiles(region=None, width=100, height=100, overlap=0)[source]¶

Split a region into a list of overlapping tiles defined as (N, S, E, W).

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_in_overlapping_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_in_overlapping_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)]]

grass.pygrass.modules.grid.split.split_region_tiles(region=None, width=100, height=100)[source]¶

Split a region into a list of tiles defined as (start_row, end_row, start_col, end_col).

Parameters

region (Region object) – a Region object to split
width (int) – the width of tiles
height (int) – the width of tiles