# pROC 1.13.0

pROC 1.13.0 was just released with bug fixes and a new feature.

## Infinite values in predictor

Following the release of pROC 1.12, it quickly became clear with issue #30 that infinite values were handled differently by the different algorithms of pROC. The problem with these values is that they cannot be thresholded. An `Inf`

will always be greater than any value. This means that in some cases, it may not be possible to reach 0 or 100% specificity or sensitivity. This also revealed that threshold-agnostic algorithms such as `algorithm="2"`

or the DeLong theta calculations would happily reach 0 or 100% specificity or sensitivity in those case, although those values are unattainable.

Starting with 1.13.0, when pROC's `roc`

function finds any infinite value in the `predictor`

argument, or in `controls`

or `cases`

, it will return `NaN`

(not a number).

## Numerical accuracy

The handling of near ties close to + or - Infinity or 0 has been improved by calculating the threshold (which is the mean between two consecutive values) differently depending on the mean value itself. This allows preserving as much precision close to 0 without maxing out large absolute values.

## New argument for ggroc

`ggroc`

can now take a new value for the `aes`

argument, `aes="group"`

. Consistent with ggplot2, it allows to curves with identical aesthetics to be split in different groups. This is especially useful for instance in facetted plots.

library(pROC) data(aSAH) roc.list <- roc(outcome ~ s100b + ndka + wfns, data = aSAH) g.list <- ggroc(roc.list) g.group <- ggroc(roc.list, aes="group") g.group + facet_grid(.~name)

Facetting of 3 ROC curves with ggroc.

## Getting the update

The update has just been accepted on CRAN and should be online soon. Once it is out, update your installation by simply typing:

install.packages("pROC")

The full changelog is:

`roc`

now returns`NaN`

when predictor contains infinite values ( issue #30).- Better handling of near-ties near +-Infinity and 0.
`ggroc`

supports`aes="group"`

to allow curves with identical aesthetics.

Xavier Robin

Published Monday, September 24, 2018 20:09 CEST

Permalink: /blog/2018/09/24/proc-1.13.0

Tags:
pROC

Comments: 0

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