Create a barplot of the values of a RasterLayer. For large datasets a regular sample with a size of approximately `maxpixels`

is used.

```
# S4 method for RasterLayer
barplot(height, maxpixels=1000000, digits=0, breaks=NULL, col=rainbow, ...)
```

## Arguments

- height
RasterLayer

- maxpixels
integer. To regularly subsample very large objects

- digits
integer used to determine how to `round`

the values before tabulating. Set to `NULL`

or to a large number if you do not want any rounding

- breaks
breaks used to group the data as in `cut`

- col
a color generating function such as `rainbow`

, or a vector of colors

- ...
additional arguments for plotting as in `barplot`

## Value

A numeric vector (or matrix, when `beside = TRUE`

) of the coordinates of the bar midpoints, useful for adding to the graph. See `barplot`

## Examples

```
f <- system.file("external/test.grd", package="raster")
r <- raster(f)
barplot(r, digits=-2, las=2, ylab='Frequency')
op <- par(no.readonly = TRUE)
par(mai = c(1, 2, .5, .5))
barplot(r, breaks=10, col=c('red', 'blue'), horiz=TRUE, digits=NULL, las=1)
par(op)
```