Get statistical test results for the plotted data
Arguments
- df
data frame containing the data
- rep_summary
summary statistic to use for testing
- cond
column name for the condition
- repl
column name for the replicate
- ncond
number of unique values in cond
- nrepl
number of unique values in repl
- stats_test
string for statistical test to use, select ("para_unpaired", "para_paired", "nonpara_unpaired", or "nonpara_paired")