PRC_df: Generate data.frame for the precision recall curve.
In ZW-xjtlu/exomePeak2Test: Easy test of the exomePeak2 performance.

Generate data.frame for the precision recall curve.

1	PRC_df(result_lst, gt_gr, N = 60, group_name = "prc")

`result_lst`	a list generated by the function `get_predictive_values`.
`gt_gr`	a GRanges for the ground truce of positive methylation sites, recommended to be all single based in width.
`N`	number of points returned for each curve, default = 60.
`group_name`	a character for the name of the group returned, default = "prc".

whistle_predict <- readRDS("predictedResults.rds")
whistle_gr <- readRDS("exon_DRACH.rds")
whistle_gr$prob <- whistle_predict
result_lst <- readRDS("hESC_C_noGC.rds")
gt_gr <- whistle_gr[whistle_gr$prob > 0.5]
plot_df <- PRC_df(result_lst = result_lst, gt_gr = gt_gr, N = 100, group_name = "no GC")