Adding roc file and simple.roc function

NAMESPACE

@@ -2,4 +2,5 @@
 
 export(remapVariable)
 export(selectValid)
+export(simple.roc)
 export(sumWithNA)

R/roc.R

@@ -0,0 +1,60 @@
+#' Create a ROC curve
+#'
+#' @param labels vector of outcomes
+#' @param scores vector of variable values
+#' @param decreasing ordering of scores
+#'
+#' @return data frame with columns TPR, FPR, labels, scores, V 
+#' V is combination of V0 (negative cases) and V1 (positive cases)
+#' V0 is portion of positive cases with value larger than score
+#' V1 is portion of negative cases with value below score
+#'
+#' @export
+
+simple.roc <- function(labels, scores, decreasing = TRUE) {
+  # Odstranimo NA vrednosti iz labels in scores
+  valid_data = stats::complete.cases(labels, scores)
+  labels = labels[valid_data]
+  scores = scores[valid_data]
+
+  labels <- labels[order(scores, decreasing=decreasing)]
+  scores <- scores[order(scores, decreasing=decreasing)]
+
+  labels = base::as.logical(labels)
+
+  x = base::data.frame(TPR = base::cumsum(labels) / base::sum(labels),
+                 FPR = base::cumsum(!labels) / base::sum(!labels),
+                 labels, scores)
+
+  s1 = scores[labels]
+  s0 = scores[!labels]
+  #V0 are 0 components of test, for each test-negative case find number of positive cases with value above it (ideally, count is equal to n1, number of positive cases)
+  V0 = base::sapply(s0, psi01, s=s1)
+  #V1 are 1 components of test; for each test-positive case find number of negative cases with score below its score (ideally, count is equal to n0, number of negative cases)
+  V1 = base::sapply(s1, psi10, s=s0)
+  n0=base::length(s0)
+  n1=base::length(s1)
+  #convert V0 to portions, to [0,1] range
+  V0=V0/n1
+  #convert V1 to portions, to [0,1] range
+  V1=V1/n0
+
+  V = labels
+  V[labels] <- V1
+  V[!labels] <- V0
+  x$V = V
+  x
+}
+
+psi01 <- function(y, s) {
+  v1 = base::sum(s > y, na.rm = TRUE)
+  v2 = base::sum(s == y, na.rm = TRUE)
+  v1 + 0.5 * v2
+}
+
+psi10 <- function(x, s) {
+  v1 = base::sum(s < x, na.rm = TRUE)
+  v2 = base::sum(s == x, na.rm = TRUE)
+  v1 + 0.5 * v2
+}
+

man/simple.roc.Rd

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+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/roc.R
+\name{simple.roc}
+\alias{simple.roc}
+\title{Create a ROC curve}
+\usage{
+simple.roc(labels, scores, decreasing = TRUE)
+}
+\arguments{
+\item{labels}{vector of outcomes}
+
+\item{scores}{vector of variable values}
+
+\item{decreasing}{ordering of scores}
+}
+\value{
+data frame with columns TPR, FPR, labels, scores, V
+V is combination of V0 (negative cases) and V1 (positive cases)
+V0 is portion of positive cases with value larger than score
+V1 is portion of negative cases with value below score
+}
+\description{
+Create a ROC curve
+}