deleted and moved .py files

exp/noise.py

@@ -0,0 +1,13 @@
+# -*- coding: utf-8 -*-
+"""
+Created on Fri May  2 10:28:27 2014
+
+@author: rlabbe
+"""
+import numpy.random
+def white_noise (sigma2=1.):
+    return sigma2 * numpy.random.randn()
+
+
+if __name__ == "__main__":
+    assert white_noise(.0) == 0.