A fold change of X in matrix entry i,j means that for replicate j, the baseline mean number of reads (reads_per_transcript[i]) will be multiplied by X.
should probably be
A fold change of X in matrix entry i,j means that for group j, the baseline mean number of reads (reads_per_transcript[i]) will be multiplied by X.
https://github.com/alyssafrazee/polyester/blob/29263d1a15ee7e33adef5d2d6aeeb93a6cb73d92/R/simulate_experiment.R#L135-L149
should probably be