# cellStats

##### Statistics across cells

Compute statistics for the cells of each layer of a Raster* object. In the `raster`

package, functions such as max, min, and mean, when used with Raster* objects as argument, return a new Raster* object (with a value computed for each cell). In contrast, cellStats returns a single value, computed from the all the values of a layer. Also see `layerStats`

##### Usage

```
# S4 method for RasterLayer
cellStats(x, stat='mean', na.rm=TRUE, asSample=TRUE, ...)
```# S4 method for RasterStackBrick
cellStats(x, stat='mean', na.rm=TRUE, asSample=TRUE, ...)

##### Arguments

- x
Raster* object

- stat
The function to be applied. See Details

- na.rm
Logical. Should

`NA`

values be removed?- asSample
Logical. Only relevant for

`stat=sd`

in which case, if`TRUE`

, the standard deviation for a sample (denominator is`n-1`

) is computed, rather than for the population (denominator is`n`

)- ...
Additional arguments

##### Details

`cellStats`

will fail (gracefully) for very large Raster* objects except for a number of known functions: sum, mean, min, max, sd, 'skew' and 'rms'. 'skew' (skewness) and 'rms' (Root Mean Square) must be supplied as a character value (with quotes), the other known functions may be supplied with or without quotes. For other functions you could perhaps use a sample of the RasterLayer that can be held in memory (see `sampleRegular`

)

##### Value

Numeric

##### See Also

##### Examples

```
# NOT RUN {
r <- raster(nrow=18, ncol=36)
r[] <- runif(ncell(r)) * 10
# works for large files
cellStats(r, 'mean')
# same, but does not work for very large files
cellStats(r, mean)
# multi-layer object
cellStats(brick(r,r), mean)
# }
```

*Documentation reproduced from package raster, version 2.9-5, License: GPL (>= 3)*