diff -r 000000000000 -r 0efde00f9229 Z-trans/pz.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Z-trans/pz.py	Fri May 27 14:24:59 2011 +0530
@@ -0,0 +1,21 @@
+#!/usr/bin/python
+# 4.3
+
+import pylab as pl
+
+z = pl.array([[0],[5./12]])
+p = pl.array([[1./2],[1./3]])
+
+def zplane(z, p):
+    pl.figure(figsize=(8,8))
+    x = pl.linspace(-1.5, 1.5)
+    pl.plot(pl.zeros_like(x), x, 'b.', x, pl.zeros_like(x), 'b.', markersize=2)
+    x = pl.linspace(0, 2*pl.pi, 100)
+    pl.plot(pl.cos(x), pl.sin(x), 'b.', markersize=2)
+    pl.plot(z, pl.zeros_like(z), 'ro', p, pl.zeros_like(p), 'rx', markersize=8)
+    pl.xlabel('Real part')
+    pl.ylabel('Imaginary part')
+
+zplane(z, p)
+
+pl.show()