R/conf_mtx.R

In mbadge/AnalysisToolkitR: Objects and Functions for general data analysis

Tab.ClassifierPoint.confusion_matrix <- function(Classifier){
    table(predicted=Classifier@Y_,
          actual = Classifier@Y)
}

Tab.ClassifierCurve.confusion_matrix <- function(Classifier)
{
    sens_thres = 0.8
    pred <- ROCR::prediction(predictions=Classifier@pY, labels=Classifier@Y)
    target_cutoff <- pred %>%
        ROCR::performance("tpr") %>%
        (function(perf) {
            data.frame(
                tpr = perf %>% slot("y.values") %>% unlist,
                cutoff = perf %>% slot("x.values") %>% unlist)}) %>%
        filter(tpr >= sens_thres) %>%
        head(1) %>%
        magrittr::use_series(cutoff)
    Classifier@pY %>%
        purrr::map_chr(~ifelse(. >= target_cutoff, 'critical', '_routine')) %>%
        factor(ordered=T) %>%
        table(predicted=.,
              actual = Classifier@Y)
}

# From /meta/code/lib/R/MyClassifiers/R/Tables.R
# .Tab.ClassifierCurve.confusion_matrix <- function(Classifier){
#     sens_thres = 0.8
#     target_cutoff <- Classifier@pred %>%
#         performance("tpr") %>%
#         (function(perf) {
#             data.frame(
#                 tpr = perf %>% slot("y.values") %>% unlist,
#                 cutoff = perf %>% slot("x.values") %>% unlist)}) %>%
#         filter(tpr >= sens_thres) %>%
#         head(1) %>%
#         use_series(cutoff)
#     Classifier@pY %>%
#         map_chr(~ifelse(. >= target_cutoff, 'critical', '_routine')) %>%
#         factor(ordered=T) %>%
#         table(Classifier@Y)}