# cellStats

##### Cell statistics

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

```
## S3 method for class 'RasterLayer':
cellStats(x, stat='mean', na.rm=TRUE, asSample=TRUE, ...)
## S3 method for class '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 `sampleRandom`

and `sampleRegular`

)

##### Value

- Numeric

##### See Also

##### Examples

```
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 2.1-41, License: GPL (>= 3)*