The function takes in a boolean value and a numeric value, which it uses to decide what to output.
nullreturn(IS.list, type = 1)Indicator of whether the data frame being input is list or not.
If type = 1(default) return directional null plot. If type = 2 return non directional null plot.
The function returns either returns a data frame or the value NULL.
nullreturn is a function that returns NULL for single df inputs that don't hold true for threshold values. It returns an empty dataframe for list inputs which don't satisfy the cutoff's
Xingpeng Li & Siddhartha Pachhai RVA - RNAseq Visualization Automation tool.