--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/python/rowjoin.py	Fri May 27 14:24:59 2011 +0530
@@ -0,0 +1,32 @@
+#!/usr/bin/python
+# Superposes two polynomial matrices. 
+
+import pylab as pl
+from polyfuncs import polsize
+
+def rowjoin(P1, degP1, P2, degP2):
+    
+    rP1, cP1 = polsize(P1, degP1)
+    rP2, cP2 = polsize(P2, degP2)
+    if not cP1 == cP2:
+        print 'rowjoin: Inconsistent numbers of columns'
+        exit()
+
+    rP = rP1 + rP2
+    cP = cP1
+    degP = max(degP1, degP2)
+
+    P = pl.atleast_2d(pl.zeros((rP,(degP+1)*cP)))
+    P[0:rP1,0:(degP1+1)*cP1] = P1
+    P[rP1:rP,0:(degP2+1)*cP2] = P2
+
+    return P, degP
+
+if __name__== "__main__":
+    s = """P = pl.array([[1, 2, 3, 4, 1, 2, 3, 4],
+           [9, 10, 11, 12, 9, 10, 11, 12],
+           [5, 6, 7, 8, 5, 6, 7, 8]])"""
+    print s
+    exec(s)
+    print """rowjoin(P, 3, P, 3)"""
+    print rowjoin(P, 3, P, 3)