# Find the boundaries of a convex set

### Description

Finds the boundaries of a bounded convex set along a specified
straight line, using a bisection approach. It is mainly intended for
use within `arms`

.

### Usage

1 | ```
convex.bounds(x, dir, indFunc, ..., tol=1e-07)
``` |

### Arguments

`x` |
a point within the set |

`dir` |
a vector specifying a direction |

`indFunc` |
indicator function of the set |

`...` |
parameters passed to |

`tol` |
tolerance |

### Details

Uses a bisection algorithm along a line having parametric representation
`x + t * dir`

.

### Value

A vector `ans`

of length two. The boundaries of the set are
`x + ans[1] * dir`

and `x + ans[2] * dir`

.

### Author(s)

Giovanni Petris GPetris@uark.edu

### Examples

1 2 | ```
## boundaries of a unit circle
convex.bounds(c(0,0), c(1,1), indFunc=function(x) crossprod(x)<1)
``` |