This function can be used to suggest chunk sizes (always a number of entire rows), and corresponding row numbers, to be used when processing Raster* objects in chunks. Normally used together with `writeValues`

.

```
# S4 method for Raster
blockSize(x, chunksize, n=nlayers(x), minblocks=4, minrows=1)
```

## Arguments

- x
Raster* object

- chunksize
Integer, normally missing. Can be used to set the block size; unit is number of cells. Block size is then computed in units of number of rows (always >= 1)

- n
Integer. number of layers to consider. The function divides chunksize by n to determine blocksize

- minblocks
Integer. Minimum number of blocks

- minrows
Integer. Minimum number of rows in each block

## Value

A list with three elements:

`rows`

, the suggested row numbers at which to start the blocks for reading and writing,

`nrows`

, the number of rows in each block, and,

`n`

, the total number of blocks

## Examples

```
r <- raster(system.file("external/test.grd", package="raster"))
blockSize(r)
#> $row
#> [1] 1 30 59 88
#>
#> $nrows
#> [1] 29 29 29 28
#>
#> $n
#> [1] 4
#>
```