Changeset 8569

Timestamp:

Sep 10, 2012, 6:47:31 PM (13 years ago)

Author:

steve

Message:

Speedup to interpolate routine in quantity_ext.c

Location:

trunk/anuga_core/source/anuga/abstract_2d_finite_volumes

Files:

• quantity.py (modified) (2 diffs)
• quantity_ext.c (modified) (4 diffs)

trunk/anuga_core/source/anuga/abstract_2d_finite_volumes/quantity.py

@@ -311 +311 @@
     # @brief Compute interpolated values at edges and centroid.
     # @note vertex_values must be set before calling this.
-    def interpolate(self):
+    def interpolate_old(self):
         """Compute interpolated values at edges and centroid
         Pre-condition: vertex_values have been set
@@ -337 +337 @@
         self.interpolate_from_vertices_to_edges()
 
+
+    ##
+    # @brief Compute interpolated values at edges and centroid.
+    # @note vertex_values must be set before calling this.
+    def interpolate(self):
+        """Compute interpolated values at edges and centroid
+        Pre-condition: vertex_values have been set
+        """
+        from quantity_ext import interpolate
+        interpolate(self)
+
+
     def interpolate_from_vertices_to_edges(self):
         # Call correct module function (either from this module or C-extension)
+
+        from quantity_ext import interpolate_from_vertices_to_edges
         interpolate_from_vertices_to_edges(self)
 
     def interpolate_from_edges_to_vertices(self):
         # Call correct module function (either from this module or C-extension)
+
+        from quantity_ext import interpolate_from_edges_to_vertices
         interpolate_from_edges_to_vertices(self)
 

trunk/anuga_core/source/anuga/abstract_2d_finite_volumes/quantity_ext.c

@@ -663 +663 @@
 }
 
+int _interpolate(int N,
+                 double* vertex_values,
+                 double* edge_values,
+                 double* centroid_values) {
+
+        int k, k3;
+        double q0, q1, q2;
+
+
+        for (k=0; k<N; k++) {
+                k3 = 3*k;
+
+                q0 = vertex_values[k3 + 0];
+                q1 = vertex_values[k3 + 1];
+                q2 = vertex_values[k3 + 2];
+
+                centroid_values[k] = (q0+q1+q2)/3.0;
+
+                edge_values[k3 + 0] = 0.5*(q1+q2);
+                edge_values[k3 + 1] = 0.5*(q0+q2);
+                edge_values[k3 + 2] = 0.5*(q0+q1);
+        }
+        return 0;
+}
+
 int _interpolate_from_vertices_to_edges(int N,
                                         double* vertex_values,
@@ -984 +1009 @@
 
         return Py_BuildValue("");
+}
+
+
+
+PyObject *interpolate(PyObject *self, PyObject *args) {
+        //
+        //Compute edge and centroid values from vertex values using linear interpolation
+        //
+
+        PyObject *quantity;
+        PyArrayObject *vertex_values, *edge_values, *centroid_values;
+
+        int N, err;
+
+        // Convert Python arguments to C
+        if (!PyArg_ParseTuple(args, "O", &quantity)) {
+          PyErr_SetString(PyExc_RuntimeError,
+                          "quantity_ext.c: interpolate could not parse input");
+          return NULL;
+        }
+
+        vertex_values = get_consecutive_array(quantity, "vertex_values");
+        edge_values = get_consecutive_array(quantity, "edge_values");
+        centroid_values = get_consecutive_array(quantity, "centroid_values");
+
+        N = vertex_values -> dimensions[0];
+
+        err = _interpolate(N,
+                           (double*) vertex_values -> data,
+                           (double*) edge_values -> data,
+                           (double*) centroid_values -> data);
+
+        if (err != 0) {
+          PyErr_SetString(PyExc_RuntimeError,
+                          "Interpolate could not be computed");
+          return NULL;
+        }
+
+        // Release and return
+        Py_DECREF(vertex_values);
+        Py_DECREF(edge_values);
+        Py_DECREF(centroid_values);
+
+        return Py_BuildValue("");
+
 }
 
@@ -2193 +2263 @@
         {"saxpy_centroid_values", saxpy_centroid_values, METH_VARARGS, "Print out"},
         {"compute_gradients", compute_gradients, METH_VARARGS, "Print out"},
-    {"compute_local_gradients", compute_gradients, METH_VARARGS, "Print out"},
+        {"compute_local_gradients", compute_gradients, METH_VARARGS, "Print out"},
         {"extrapolate_from_gradient", extrapolate_from_gradient,
                 METH_VARARGS, "Print out"},
@@ -2206 +2276 @@
                 interpolate_from_edges_to_vertices,
                 METH_VARARGS, "Print out"},
+        {"interpolate", interpolate, METH_VARARGS, "Print out"},
         {"average_vertex_values", average_vertex_values, METH_VARARGS, "Print out"},            
         {NULL, NULL, 0, NULL}   // sentinel