Changeset 2402 for inundation/pmesh/mesh_interface.py

Timestamp:

Feb 14, 2006, 3:29:10 PM (19 years ago)

Author:

duncan

Message:

added auto geo-reffing in create_mesh_from_regions

File:

• inundation/pmesh/mesh_interface.py (modified) (5 diffs)

inundation/pmesh/mesh_interface.py

@@ -4 +4 @@
 #!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
-from coordinate_transforms.geo_reference import Geo_reference
+from coordinate_transforms.geo_reference import Geo_reference,DEFAULT_ZONE
 from utilities.polygon import populate_polygon
+from utilities.numerical_tools import ensure_numeric
+from Numeric import Float
 
 # This is due to pmesh being a package and a module and
@@ -13 +15 @@
 except ImportError:  
     from mesh import Mesh
-    
+
+
 def create_mesh_from_regions(bounding_polygon,
                              boundary_tags,
@@ -24 +27 @@
     """Create mesh from bounding polygons, and resolutions.
 
-    Polygon is a list of points in Eastings and Northings, absolute
+    bounding_polygon is a list of points in Eastings and Northings,
+    relative to the poly_geo_reference.
 
     Boundary tags is a dictionary of symbolic tags. For every tag there
@@ -39 +43 @@
 
     poly_geo_reference is the geo_reference of the polygons.
-    If none, assume absolute.
+    If none, assume absolute.  Please pass one though, since absolute
+    references have a zone.
     
     mesh_geo_reference is the geo_reference of the mesh to be created.
-    If none, assume absolute.
+    If none is given one will be automatically generated.  It was use
+    the lower left hand corner of  bounding_polygon (absolute)
+    as the x and y values for the geo_ref.
     
     Returns the mesh instance if no finename is given
     
     """
+    #FIXME (OLE-DSG)
     # To do make maximum_triangle_area optional?
     # check the segment indexes - throw an error if they are out of bounds
-
-    #IDEA (Ole): Let us work out what the mesh_geo_reference is automatically:
-    #If bounding_polygon is absolute it would look as follows:
-    #
-    #from utilities.numerical_tools import ensure_numeric    
-    #bounding_polygon = ensure_numeric(bounding_polygon) #Make it Numeric
-    #xllcorner = min(bounding_polygon[:,0])
-    #yllcorner = min(bounding_polygon[:,1])    
-    #
-    #mesh_geo_reference = Geo_reference(xllcorner = xllcorner,
-    #                                   yllcorner = yllcorner,
-    #                                   zone = "zone from bounding polygon")
     #
     #In addition I reckon the polygons could be of class Geospatial_data 
+
+    if mesh_geo_reference is None:
+        bounding_polygon = ensure_numeric(bounding_polygon, Float)
+        xllcorner = min(bounding_polygon[:,0])
+        yllcorner = min(bounding_polygon[:,1])    
+        #
+        if poly_geo_reference is None:
+            zone = DEFAULT_ZONE
+        else:
+            zone = poly_geo_reference.get_zone()
+            [(xllcorner,yllcorner)] = poly_geo_reference.get_absolute( \
+            [(xllcorner,yllcorner)])
+        # create a geo_ref, based on the llc of the bounding_polygon
+        mesh_geo_reference = Geo_reference(xllcorner = xllcorner,
+                                       yllcorner = yllcorner,
+                                       zone = zone)
 
     m = Mesh(geo_reference=mesh_geo_reference)
@@ -118 +130 @@
     else:
         m.export_mesh_file(filename)
+
+