I'm running stageR as part of a pipeline based on DRIMSeq and wanted to know what it means when the transcript level padj is equal to 0, particularly when the gene is non-significant. I'm pretty sure that in some cases if the padj is 0 it means that the chance of it being different due to chance is 0. There are a lot more 0s than I would expect in sites where the gene padj is non-significant. One example, I have a gene padj that's >0.9 but both of the sites I'm looking at have a padj of 0.
I have a couple of suspicions about why this is: either because it defaults to this if the comparative difference is or it uses 0 as a substitute to NA. Am I thinking along the right lines? Are the 0s real or are they likely to be a quirk of the package?