# eightneighbours: Count Number of Neighbours in a Rectangular Cellular Grid. In simecol: Simulation of Ecological (and Other) Dynamic Systems

## Description

This function returns the sum of the eight neibours of a cell within a matrix. It can be used to simulate simple cellular automata, e.g. Conway's Game of Life.

## Usage

 ```1 2``` ``` eightneighbours(x) eightneighbors(x) ```

## Arguments

 `x` The cellular grid, which typically contains integer values of zero (dead cell) or one (living cell).

## Value

A matrix with the same structure as `x`, but with the sum of the neighbouring cells of each cell.

`seedfill`, `neighbours`, `conway`

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23``` ```n <- 80; m <- 80 x <- matrix(rep(0, m*n), nrow = n) x[round(runif(1500, 1, m*n))] <- 1 ## uncomment this for another figure #x[40, 20:60] <- 1 image(x, col=c("wheat", "grey", "red")) x2 <- x for (i in 2:10){ nb <- eightneighbours(x) ## survive with 2 or 3 neighbours xsurv <- ifelse(x > 0 & (nb == 2 | nb ==3), 1, 0) ## generate for empty cells with 3 neigbours xgen <- ifelse(x == 0 & nb == 3, 1, 0) x <- ((xgen + xsurv)>0) x2 <- ifelse(x2>1, 1, x2) x2 <- ifelse(x>0, 2, x2) image(x2, col=c("wheat", "grey", "red"), add=TRUE) } ```

### Example output

```Loading required package: deSolve
```

simecol documentation built on June 3, 2018, 5:07 p.m.