RT Journal Article SR Electronic T1 SpectralTDF: transition densities of diffusion processes with time-varying selection parameters, mutation rates, and effective population sizes JF bioRxiv FD Cold Spring Harbor Laboratory SP 029736 DO 10.1101/029736 A1 Matthias Steinrücken A1 Ethan M. Jewett A1 Yun S. Song YR 2015 UL http://biorxiv.org/content/early/2015/10/27/029736.abstract AB In the Wright-Fisher diffusion, the transition density function (TDF) describes the time-evolution of the population-wide frequency of an allele. This function has several practical applications in population genetics, and computing it for biologically realistic scenarios with selection and demography is an important problem. We develop an efficient method for finding a spectral representation of the TDF for a general model where the effective population size, selection coefficients, and mutation parameters vary over time in a piecewise constant manner. The method, called spectralTDF, is available at https://sourceforge.net/projects/spectraltdf/.