# Determines for one or more points whether they belong to the alpha-convex hull

### Description

This function determines for one or more points *p* whether they belong to the *α*-convex hull of a sample.

### Usage

1 | ```
inahull(ahull.obj, p)
``` |

### Arguments

`ahull.obj` |
Object of class |

`p` |
Numeric vector with two components describing a point in the plane or two-column matrix of points. |

### Details

The complement of the *α*-convex hull of a sample is calculated by `complement`

. The function `inahull`

checks whether each point in *p* belongs to any of the open balls or halfplanes that define the complement.

### Value

`in.ahull` |
A logical vector specifying whether each point in |

### See Also

`ahull`

, `complement`

.

### Examples

1 2 3 4 5 6 7 8 9 10 11 12 13 | ```
## Not run:
# Random sample in the unit square
x <- matrix(runif(100), nc = 2)
# Value of alpha
alpha <- 0.2
# alpha-convex hull
ahull.obj <- ahull(x, alpha = alpha)
# Check if the point (0.5, 0.5) belongs to the alpha-convex hull
inahull(ahull.obj, p = c(0.5, 0.5))
# Check if the points (0.5, 0.5) and (2, 2) belong to the alpha-convex hull
inahull(ahull.obj, p = rbind(c(0.5, 0.5), c(2, 2)))
## End(Not run)
``` |