# cueAccuracy: Calculate the accuracy of using a cue to predict a criterion. In heuristica: Heuristics Including Take the Best and Unit-Weight Linear

## Description

`cueValidity` counts only correct and incorrect inferences, ignoring cases where a cue does not discriminate. Cue accuracy gives those cases a weight of 0.5, the expected accuracy of guessing. It is calculated as (correct + 0.5 * guesses) / (correct + incorrect + guesses).

## Usage

 `1` ```cueAccuracy(criterion, cue, replaceNanWith = 0.5) ```

## Arguments

 `criterion` A vector of values to be predicted. `cue` A vector of values to predict with. Should have the same length as the criterion. `replaceNanWith` The value to return as cue validity in case it cannot be calculated, e.g. no variance in the values.

## Value

The cue accuracy, a value in the range [0,1].

`cueValidity` for an alternate measure used in Take The Best.
 ```1 2 3 4 5 6``` ```cueValidity(c(5,1), c(1,0)) cueAccuracy(c(5,1), c(1,0)) # Both return 1. cueValidity(c(5,2,1), c(1,0,0)) cueAccuracy(c(5,2,1), c(1,0,0)) # Cue validity still returns 1 but cue accuracy returns (2+0.5)/3 = 0.833. ```