getValuesBlock: Get a block of raster cell values

In raster: Geographic Data Analysis and Modeling

Description

getValuesBlock returns values for a block (rectangular area) of values of a Raster* object.

Usage

## S4 method for signature 'RasterLayer'
getValuesBlock(x, row=1, nrows=1, col=1, ncols=(ncol(x)-col+1), format='', ...)

## S4 method for signature 'RasterBrick'
getValuesBlock(x, row=1, nrows=1, col=1, ncols=(ncol(x)-col+1), lyrs, ...)

## S4 method for signature 'RasterStack'
getValuesBlock(x, row=1, nrows=1, col=1, ncols=(ncol(x)-col+1), lyrs, ...)

Arguments

x	Raster* object
row	positive integer. Row number to start from, should be between 1 and nrow(x)
nrows	positive integer. How many rows? Default is 1
col	positive integer. Column number to start from, should be between 1 and ncol(x)
ncols	positive integer. How many columns? Default is the number of columns left after the start column
format	character. When x is a RasterLayer, if format='matrix' or format='m', a matrix is returned instead of a vector. If format='matrix', it is a nrow x ncol matrix. If format='m' it is a 1 column matrix (the benefit is that the type of output is now the same for all Raster objects)
lyrs	integer (vector). Which layers? Default is all layers (1:nlayers(x))
...	additional arguments (none implemented)

Value

matrix or vector (if (x=RasterLayer), unless format='matrix')

See Also

getValues

Examples

r <- raster(system.file("external/test.grd", package="raster"))
b <- getValuesBlock(r, row=100, nrows=3, col=10, ncols=5)
b 
b <- matrix(b, nrow=3, ncol=5, byrow=TRUE)
b

logo <- brick(system.file("external/rlogo.grd", package="raster"))
getValuesBlock(logo, row=35, nrows=3, col=50, ncols=3, lyrs=2:3)

Example output

Loading required package: sp
 [1] 454.412 440.488 421.193 396.460 365.566 483.079 467.769 444.945 418.093
[10] 390.002 532.368 513.638 481.389 446.935 416.298
        [,1]    [,2]    [,3]    [,4]    [,5]
[1,] 454.412 440.488 421.193 396.460 365.566
[2,] 483.079 467.769 444.945 418.093 390.002
[3,] 532.368 513.638 481.389 446.935 416.298
      green blue
 [1,]   168  220
 [2,]   176  231
 [3,]   175  226
 [4,]   167  219
 [5,]   176  230
 [6,]   175  226
 [7,]   167  219
 [8,]   176  230
 [9,]   175  224

raster documentation built on Jan. 5, 2021, 3:01 a.m.