ggroc.list parameter legacy.axes break

[Baytars]

Describe the bug Plotting a list of ROC objects with ggroc with parameter legacy.axes = T raises error:

geom_path: Each group consists of only one observation. Do you need to adjust the group
aesthetic?
Warning message:
Removed 366 row(s) containing missing values (geom_path). 

Modifying the source code solves the error. For get.aes.for.ggplot:

if(roc$percent) {
    if (legacy.axes) {
      aes_list <- list(x = "FNR", y = "sensitivity")
      xlims <- ggplot2::scale_x_continuous(lim=c(0, 100))		
    }
    else {
      aes_list <- list(x = "specificity", y = "sensitivity")
      xlims <- ggplot2::scale_x_reverse(lim=c(100, 0))
    }
  }
  else {
    if (legacy.axes) {
      aes_list <- list(x = "FNR", y = "sensitivity")
      xlims <- ggplot2::scale_x_continuous(lim=c(0, 1))
    }
    else {
      aes_list <- list(x = "specificity", y = "sensitivity")
      xlims <- ggplot2::scale_x_reverse(lim=c(1, 0))
    }
  }

For ggroc.list:

# Add a "name" colummn
  for (i in seq_along(coord.dfs)) {
    coord.dfs[[i]]$name <- names(coord.dfs)[i]
  }
  
  # Add a "1-specificity" colummn
  for (i in seq_along(coord.dfs)) {
    if(data[[1]]$percent) {
      coord.dfs[[i]]$FNR <- 100 - coord.dfs[[i]]$specificity
    }
    else {
      coord.dfs[[i]]$FNR <- 1 - coord.dfs[[i]]$specificity
    }
  }

This issue comes from misinterpretation of aes_list <- list(x = "1-specificity", y = "sensitivity")

> R.version
               _                           
platform       x86_64-pc-linux-gnu         
arch           x86_64                      
os             linux-gnu                   
system         x86_64, linux-gnu           
status                                     
major          4                           
minor          1.3                         
year           2022                        
month          03                          
day            10                          
svn rev        81868                       
language       R                           
version.string R version 4.1.3 (2022-03-10)
nickname       One Push-Up

Package pROC version 1.18.0

[xrobin]

Hi Baytars, thanks for the bug report.

I can't reproduce it.

library(pROC)
data(aSAH)
rocobj <- roc(aSAH$outcome, aSAH$s100b)
ggroc(rocobj, legacy.axes = TRUE)

Works fine for me, and produce a plot with legacy axes as expected.

The bug report template asked for extra information that can help reproduce the issue, in particular sessionInfo and the exact code that triggered the error. It would be really helpful if you could include that information.

[xrobin]

@Baytars: I am closing the bug report as I can't reproduce it. Please feel free to reopen it and provide the extra details requested above. Thanks!