de>theta + lrate * gradient</code>. Then
for the next iteration, a set of <code>chunksize</code> samples are drawn from a Dirichlet distribution
with parameter <code>ga_gfactor * (theta + ga_lrate * gradient)</code>. If <code>ga_gfactor = "adapt"</code> then
it is set to <code>1 / max(theta)</code> at each iteration. The ITP algorithm <a href="itp_root.html">itp_root</a> is used
to find roots of the p-value function as a function of the psi0 value to get confidence intervals.
The maximum number of iteration