log_sum_of_logs

Sequence of numbers in log space $[\log(x_1), \log(x_2), ..., \log(x_n)]$.

log_values


Given a sequence of numbers $[\log(x_1), \log(x_2), ..., \log(x_n)]$, computes $\log(\sum_{i = 1}^n x_i)$.
For adding two numbers that are given in log space we use the expression <code>max(x, y) + log1p(exp(-abs(x - y)))</code>
which is a good approximation if <code>x</code> and <code>y</code> are of the same order of magnitude, but if they
are of very different sizes just returns the maximum of the two. To prevent adding numbers of very different
magnitude we iteratively add the numbers pairwise. Because of numerical issues with doing this, the order
of the input values can affect the result.


Implements tools for building and visualising admixture graphs
and for extracting equations from them. These equations can be compared to f-
statistics obtained from data to test the consistency of a graph against data --
for example by comparing the sign of f_4-statistics with the signs predicted by
the graph -- and graph parameters (edge lengths and admixture proportions) can
be fitted to observed statistics.

log_sum_of_logs: Computes the log of a sum of numbers all given in log-space.

Description

Usage

Arguments

Value