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-rw-r--r--src/boost/libs/python/example/numpy/demo_gaussian.py37
1 files changed, 37 insertions, 0 deletions
diff --git a/src/boost/libs/python/example/numpy/demo_gaussian.py b/src/boost/libs/python/example/numpy/demo_gaussian.py
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index 000000000..0b1c78995
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+++ b/src/boost/libs/python/example/numpy/demo_gaussian.py
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+# Copyright Jim Bosch 2010-2012.
+# Distributed under the Boost Software License, Version 1.0.
+# (See accompanying file LICENSE_1_0.txt or copy at
+# http://www.boost.org/LICENSE_1_0.txt)
+
+import numpy
+import gaussian
+
+mu = numpy.zeros(2, dtype=float)
+sigma = numpy.identity(2, dtype=float)
+sigma[0, 1] = 0.15
+sigma[1, 0] = 0.15
+
+g = gaussian.bivariate_gaussian(mu, sigma)
+
+r = numpy.linspace(-40, 40, 1001)
+x, y = numpy.meshgrid(r, r)
+
+z = g(x, y)
+
+s = z.sum() * (r[1] - r[0])**2
+print "sum (should be ~ 1):", s
+
+xc = (z * x).sum() / z.sum()
+print "x centroid (should be ~ %f): %f" % (mu[0], xc)
+
+yc = (z * y).sum() / z.sum()
+print "y centroid (should be ~ %f): %f" % (mu[1], yc)
+
+xx = (z * (x - xc)**2).sum() / z.sum()
+print "xx moment (should be ~ %f): %f" % (sigma[0,0], xx)
+
+yy = (z * (y - yc)**2).sum() / z.sum()
+print "yy moment (should be ~ %f): %f" % (sigma[1,1], yy)
+
+xy = 0.5 * (z * (x - xc) * (y - yc)).sum() / z.sum()
+print "xy moment (should be ~ %f): %f" % (sigma[0,1], xy)