[GRASS-SVN] r53970 - grass/trunk/lib/python/pygrass/raster

[svn_grass at osgeo.org]

Author: zarch
Date: 2012-11-22 03:31:11 -0800 (Thu, 22 Nov 2012)
New Revision: 53970

Modified:
   grass/trunk/lib/python/pygrass/raster/__init__.py
Log:
Add two functions to convert (north, east) into (row, col) and back

Modified: grass/trunk/lib/python/pygrass/raster/__init__.py
===================================================================
--- grass/trunk/lib/python/pygrass/raster/__init__.py	2012-11-22 10:29:12 UTC (rev 53969)
+++ grass/trunk/lib/python/pygrass/raster/__init__.py	2012-11-22 11:31:11 UTC (rev 53970)
@@ -36,6 +36,35 @@
 from category import Category
 from history import History
 
+
+def coor2pixel((north, east), region):
+    """Convert coordinates into a pixel row and col ::
+
+        >>> from pygrass import Region
+        >>> reg = Region()
+        >>> coor2pixel((reg.north, reg.west), reg)
+        (0.0, 0.0)
+        >>> coor2pixel((reg.south, reg.east), reg) == (reg.rows, reg.cols)
+        True
+    """
+    return (libraster.Rast_northing_to_row(north, region.c_region),
+            libraster.Rast_easting_to_col(east, region.c_region))
+
+
+def pixel2coor((row, col), region):
+    """Convert row and col of a pixel into a coordinates ::
+
+        >>> from pygrass import Region
+        >>> reg = Region()
+        >>> pixel2coor((0, 0), reg) == (reg.north, reg.west)
+        True
+        >>> pixel2coor((reg.rows, reg.cols), reg) == (reg.south, reg.east)
+        True
+    """
+    return (libraster.Rast_row_to_northing(row, region.c_region),
+            libraster.Rast_col_to_easting(col, region.c_region))
+
+
 class RasterRow(RasterAbstractBase):
     """Raster_row_access": Inherits: "Raster_abstract_base" and implements
     the default row access of the Rast library.