= EM for merged multinomial cells
{c}
For a <multinomial distribution> with two unobserved cells merged into one observed count, the conditional allocation is a <binomial distribution> with probabilities proportional to the two cell probabilities. The <expectation-maximization algorithm> replaces the missing counts by their conditional <expectations> in the parameter-dependent part of the complete-data <log-likelihood>. The <expectation> of a log-factorial normalization generally differs from its value at the expected count, but this difference is independent of the candidate parameter and does not affect the maximization step.
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