Enhanced Confusion Matrix Plot — eCM

This function generates an enhanced confusion matrix plot using the CVMS package. The plot includes visualizations of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

Usage

eCM_plot(task, trained_model, splits, add_sums = TRUE, palette = "Green")

Arguments

task: mlr3 task object specifying the task details
trained_model: mlr3 trained learner (model) object obtained after training
splits: mlr3 object defining data splits for train and test sets
add_sums: logical, indicating whether total numbers should be displayed in the plot (default: TRUE)
palette: character, the color palette for the confusion matrix (default: "Green")

Value

A confusion matrix plot visualizing sensitivity, specificity, PPV, and NPV

Examples

library("explainer")
seed <- 246
set.seed(seed)

# Load necessary packages
if (!requireNamespace("mlbench", quietly = TRUE)) stop("mlbench not installed.")
if (!requireNamespace("mlr3learners", quietly = TRUE)) stop("mlr3learners not installed.")
if (!requireNamespace("ranger", quietly = TRUE)) stop("ranger not installed.")
# Load BreastCancer dataset
utils::data("BreastCancer", package = "mlbench")
target_col <- "Class"
positive_class <- "malignant"
mydata <- BreastCancer[, -1]
mydata <- na.omit(mydata)
sex <- sample(
  c("Male", "Female"),
  size = nrow(mydata),
  replace = TRUE
)
mydata$age <- as.numeric(sample(
  seq(18, 60),
  size = nrow(mydata),
  replace = TRUE
))
mydata$sex <- factor(
  sex,
  levels = c("Male", "Female"),
  labels = c(1, 0)
)
maintask <- mlr3::TaskClassif$new(
  id = "my_classification_task",
  backend = mydata,
  target = target_col,
  positive = positive_class
)
splits <- mlr3::partition(maintask)
mylrn <- mlr3::lrn(
  "classif.ranger",
  predict_type = "prob"
)
mylrn$train(maintask, splits$train)
myplot <- eCM_plot(
  task = maintask,
  trained_model = mylrn,
  splits = splits
)
#> Warning: 'ggimage' is missing. Will not plot arrows and zero-shading.
#> Warning: 'rsvg' is missing. Will not plot arrows and zero-shading.
#> Warning: 'ggnewscale' is missing. Will not use palette for sum tiles.
#> Warning: Unknown palette: "Green"
#> Warning: 'ggimage' is missing. Will not plot arrows and zero-shading.
#> Warning: 'rsvg' is missing. Will not plot arrows and zero-shading.
#> Warning: 'ggnewscale' is missing. Will not use palette for sum tiles.
#> Warning: Unknown palette: "Green"