diff -r 000000000000 -r 0efde00f9229 freq/incr_freq.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/freq/incr_freq.py	Fri May 27 14:24:59 2011 +0530
@@ -0,0 +1,17 @@
+#!/usr/bin/python
+# 5.1
+
+import scipy as sp
+from pylab import *
+
+n = sp.arange(17)
+subplot(2,2,1), stem(n,cos(n*pi/8))
+grid,xlabel('n'),ylabel('cos(n*pi/8)')
+subplot(2,2,2), stem(n,cos(n*pi/4))
+grid,xlabel('n'),ylabel('cos(n*pi/4)')
+subplot(2,2,3), stem(n,cos(n*pi/2))
+grid,xlabel('n'),ylabel('cos(n*pi/2)')
+subplot(2,2,4), stem(n,cos(n*pi))
+grid,xlabel('n'),ylabel('cos(n*pi)')
+
+show()