--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/python/clcoef.py	Fri May 27 14:24:59 2011 +0530
@@ -0,0 +1,36 @@
+#!/usr/bin/python
+
+import pylab as pl
+from polyfuncs import polsize
+
+def clcoef(Q, degQ):
+    """Function to clear zero leading coefficient matrices
+    of a Polynomial Matrix"""
+    rQ, cQ = polsize(Q, degQ)
+    
+    if pl.allclose(Q, pl.zeros_like(Q)):
+        P = pl.zeros((rQ,cQ))
+        degP = 0
+    else:
+        P, degP = Q, degQ
+        rP, cP = rQ, cQ
+        j = degP
+        while j>=0:
+            if pl.norm(P[:, -cP:], pl.inf) < 1e-8 *pl.norm(P, pl.inf):
+                P = P[:, :j*cP]
+                degP = degP-1
+            else:
+                j=0
+            j -= 1
+    return P, degP
+
+if __name__== "__main__":
+    s = """P = pl.array([[1, 2, 3, 4, 0, 0, 0, 0],
+           [9, 10, 11, 12, 0, 0, 0, 0],
+           [5, 6, 7, 8, 0, 0, 0, 0]])"""
+    t = """degP = 3"""
+    print s, t
+    exec(s)
+    exec(t)
+    
+    print clcoef(P, degP)