# emacs: -*- mode: python; py-indent-offset: 4; indent-tabs-mode: nil -*-
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"""
Example of a demo that fits a Gaussian Mixture Model (GMM) to  a dataset
The possible number of clusters is in the [1,10] range
The proposed algorithm correctly selects a solution with 2 or 3 classes

Author : Bertrand Thirion, 2008-2009
"""
print __doc__

import numpy as np

import nipy.neurospin.clustering.gmm as gmm


dim = 2
# 1. generate a 3-components mixture
x1 = np.random.randn(100,dim)
x2 = 3+  2*np.random.randn(50,dim)
x3 = np.repeat(np.array([-2, 2], ndmin=2), 30, 0) \
     + 0.5*np.random.randn(30, dim)
x = np.concatenate((x1, x2, x3))

# 2. fit the mixture with a bunch of possible models
krange = range(1,5)
lgmm = gmm.best_fitting_GMM(x, krange,
                            prec_type='diag',
                            niter=100, delta=1.e-4,
                            ninit=1, verbose=0)

# 3, plot the result
z = lgmm.map_label(x)
gmm.plot2D(x, lgmm, z, show=1, verbose=0)