meanAcrossAssays: Private/inner/helper method to get average counts across samples
Description
This method should not be used by package users. It gets average counts
for "pre" or "post" portions (depending on the wantedColumns argument)
given the list of assays for one of the two conditions.
Usage
meanAcrossAssays(assays, wantedColumns)
Arguments
assays
A list of matrixes/dataframes.
wantedColumns
The name of the columns ("pre" or "post") whose means should be computed.
Average will be calculated on the corresponding rows of the list of matrixes/dataframe,
working on the given column.