# Plot a Complexity Parameter Table for an Rpart Fit

### Description

Gives a visual representation of the cross-validation results in an
`rpart`

object.

### Usage

1 2 |

### Arguments

`x` |
an object of class |

`minline` |
whether a horizontal line is drawn 1SE above the minimum of the curve. |

`lty` |
line type for this line |

`col` |
colour for this line |

`upper` |
what is plotted on the top axis: the size of the tree (the number of leaves), the number of splits or nothing. |

`...` |
additional plotting parameters |

### Details

The set of possible cost-complexity prunings of a tree from a nested
set. For the geometric means of the intervals of values of `cp`

for which
a pruning is optimal, a cross-validation has (usually) been done in
the initial construction by `rpart`

. The `cptable`

in the fit contains
the mean and standard deviation of the errors in the cross-validated
prediction against each of the geometric means, and these are plotted
by this function. A good choice of `cp`

for pruning is often the
leftmost value for which the mean lies below the horizontal line.

### Value

None.

### Side Effects

A plot is produced on the current graphical device.

### See Also

`rpart`

, `printcp`

, `rpart.object`