Changeset 1849

Timestamp:

Sep 21, 2005, 4:59:07 PM (19 years ago)

Author:

duncan

Message:

comments

File:

• inundation/pyvolution/sparse.py (modified) (1 diff)

inundation/pyvolution/sparse.py

@@ -232 +232 @@
 
         Sparse_CSR(A) #creates csr sparse matrix from sparse matrix
+        Matrices are not built using this format, since it's painful to
+        add values to an existing sparse_CSR instance (hence there are no
+        objects to do this.)
+
+        Rather, build a matrix, and convert it to this format for a speed
+        increase.
 
         data - a 1D array of the data
         Colind - The ith item in this 1D array is the column index of the
                  ith data in the data array
+        rowptr - 1D array, with the index representing the row of the matrix.
+                 The item in the row represents the index into colind of the
+                 first data value of this row.
+                 Regard it as a pointer into the colind array, for the ith row.
+
+                 
         """