Loading of DIPHA weight matrices.

1 files changed, 35 insertions, 0 deletions

diff --git a/phstuff/diphawrapper.py b/phstuff/diphawrapper.py
index 517a929..6dc2861 100644
--- a/phstuff/diphawrapper.py
+++ b/phstuff/diphawrapper.py
@@ -69,6 +69,41 @@ def save_weight_matrix(fname, weights):
             for j in range(0, m):
                 f.write(struct.pack("<d", factor*weights[i,j]))
 
+
+def load_weight_matrix(fname):
+    """Load a DIPHA full distance matrix as a NumPy array.
+
+    Parameters:
+    -----------
+
+    fname: Name of file to read.
+
+    Returns:
+    ----------
+
+    A NumPy array.
+
+    """
+
+    with open(fname, "rb") as f:
+        if struct.unpack('<q', f.read(8))[0] != DIPHA_MAGIC:
+            raise IOError("File %s is not a valid DIPHA file." %(fname))
+        if struct.unpack('<q', f.read(8))[0] != DIPHA_DISTANCE_MATRIX:
+            raise IOError("File %s is not a valid DIPHA matrix file." %(fname))
+
+        m = struct.unpack('<q', f.read(8))[0]
+        if m <= 0:
+            raise IOError("Matrix dimension non-sensical (%d)." %(m))
+
+        X = np.zeros((m, m))
+
+        for i in range(0, m):
+            for j in range(0, m):
+                X[i, j] = struct.unpack('<d', f.read(8))[0]
+
+    return X
+    
+
 def save_masked_weight_matrix(fname, weights):
     """Write a masked NumPy weight matrix to a DIPHA sparse distance
     matrix file, keeping edges only for unmasked entries. Corresponds