.. _book_fig_chapter6_fig_EM_metallicity:


EM example: Gaussian Mixture Models
-----------------------------------
Figure 6.6

A two-dimensional mixture of Gaussians for the stellar metallicity data. The
left panel shows the number density of stars as a function of two measures of
their chemical composition: metallicity ([Fe/H]) and alpha-element abundance
([alpha/Fe]). The right panel shows the density estimated using mixtures of
Gaussians together with the positions and covariances (2-sigma levels) of
those Gaussians. The center panel compares the information criteria AIC
and BIC (see Sections 4.3.2 and 5.4.3).



.. image:: ../images/chapter6/fig_EM_metallicity_1.png
    :scale: 100
    :align: center


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