September 2012
Intermediate to advanced
486 pages
10h 41m
English
9.2 The EM algorithm
9.2.1 The idea of the EM algorithm
A useful numerical technique which finds the posterior mode, that is, the value at which
or equivalently
is a maximum, but does not provide full information on the posterior distribution is the EM algorithm. We can exemplify this by an example on genetic linkage due to Rao (1973, Section 5g) quoted by Dempster et al. (1977), by Gelfand and Smith (1990) and by Tanner (1996, Section 4.1). We have observations
with cell probabilities
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and we want to estimate η. The likelihood is then
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What we do is to augment the data
by adding further data
to produce augmented data
. It should be noted that to a considerable extent the distinction between ...