# HG changeset patch
# User Olivier Breuleux <breuleuo@iro.umontreal.ca>
# Date 1218065954 14400
# Node ID d7ed780364b3e2f99172eabecd78899738b279c8
# Parent  eac0a7d44ff075bc31ed483eaf4681512ee37963
image_tools

diff -r eac0a7d44ff0 -r d7ed780364b3 image_tools.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/image_tools.py	Wed Aug 06 19:39:14 2008 -0400
@@ -0,0 +1,39 @@
+
+import numpy
+
+
+def make_weights_image(mat, xres, yres, i, j, nrow, ncol):
+    """
+    Displays the filters implemented by a weight matrix.
+
+    Each filter corresponds to a row of mat and will be represented
+    by a xres*yres image.
+
+    Units from i to j will be included in the picture.
+
+    The picture will have nrow rows of filters and ncol columns
+    of filters. Unused spots for filters will be filled with zeros.
+
+    The return value is a matrix suitable for display with
+    matplotlib's imshow.
+    """
+
+    assert j > i
+    n = j - i
+    result = numpy.zeros((ncol * xres, nrow * yres))
+    submat = mat[i:j]
+    for k, row in enumerate(submat):
+        x = (k % ncol)*xres
+        y = (k / ncol)*yres
+        entry = row.reshape((xres, yres))
+        lmin, lmax = numpy.min(entry), numpy.max(entry)
+        ldiff = lmax - lmin
+        #entry = (entry - lmin) / ldiff
+        result[x:x + xres, y:y + yres] = entry
+    return result.T
+
+
+
+
+
+