a3.r2 {A3} | R Documentation |

## Cross-Validated `R^2`

### Description

Applies cross validation to obtain the cross-validated `R^2`

for a model: the fraction of the squared error explained by the model compared to the null model (which is defined as the average response). A pseudo `R^2`

is implemented for classification.

### Usage

```
a3.r2(y, x, simulate.fn, cv.folds)
```

### Arguments

`y` |
a vector or responses. |

`x` |
a matrix of features. |

`simulate.fn` |
a function object that creates a model and predicts y. |

`cv.folds` |
the cross-validation folds. |

### Value

A list comprising of the following elements:

`R2` |
the cross-validated |

`predicted` |
the predicted responses |

`observed` |
the observed responses |

[Package

*A3*version 1.0.0 Index]