exactPotts {bayesImageS} | R Documentation |

## Calculate the distribution of the Potts model using a brute force algorithm.

### Description

**Warning**: this algorithm is O`(k^n)`

and therefore will not scale for
`k^n > 2^{31} - 1`

### Usage

```
exactPotts(neighbors, blocks, k, beta)
```

### Arguments

`neighbors` |
A matrix of all neighbours in the lattice, one row per pixel. |

`blocks` |
A list of pixel indices, dividing the lattice into independent blocks. |

`k` |
The number of unique labels. |

`beta` |
The inverse temperature parameter of the Potts model. |

### Value

A list containing the following elements:

`expectation`

The exact mean of the sufficient statistic.

`variance`

The exact variance of the sufficient statistic.

`exp_PL`

Pseudo-likelihood (PL) approximation of the expectation of S(z).

`var_PL`

PL approx. of the variance of the sufficient statistic.

[Package

*bayesImageS*version 0.6-1 Index]