getValuesFocal: Get focal raster cell values

In raster: Geographic Data Analysis and Modeling

Description

This function returns a matrix (or matrices) for all focal values of a number of rows of a Raster* object

Usage

## S4 method for signature 'Raster'
getValuesFocal(x, row, nrows, ngb, names=FALSE, padValue=NA, array=FALSE, ...)

Arguments

x	Raster* object
row	Numeric. Row number, should be between 1 and nrow(x). Can be omitted to get all rows
nrows	Numeric. Number of rows, should be a positive integer smaller than row+nrow(x). Should be omitted if row is omitted
ngb	Neighbourhood size. Either a single integer or a vector of two integers c(nrow, ncol)
names	logical. If TRUE, the matrix returned has row and column names
padValue	numeric. The value of the cells of the "padded" rows and columns. That is 'virtual' values for cells within a neighbourhood, but outside the raster
array	logical. If TRUE and x has multiple layers, an array is returned in stead of a list of matrices
...	additional arguments (none implemented)

Value

If x has a single layer, a matrix with one row for each focal cell, and one column for each neighbourhood cell around it.

If x has multiple layers, an array (if array=TRUE) or a list of such matrices (one list element (matrix) for each layer)

See Also

getValues, focal

Examples

r <- raster(nr=5, nc=5, crs='+proj=utm +zone=12')
values(r) <- 1:25
as.matrix(r)
getValuesFocal(r, row=1, nrows=2, ngb=3, names=TRUE)
getValuesFocal(stack(r,r), row=1, nrows=1, ngb=3, names=TRUE, array=TRUE)

Example output

Loading required package: sp
     [,1] [,2] [,3] [,4] [,5]
[1,]    1    2    3    4    5
[2,]    6    7    8    9   10
[3,]   11   12   13   14   15
[4,]   16   17   18   19   20
[5,]   21   22   23   24   25
   r1c1 r1c2 r1c3 r2c1 r2c2 r2c3 r3c1 r3c2 r3c3
1    NA   NA   NA   NA    1    2   NA    6    7
2    NA   NA   NA    1    2    3    6    7    8
3    NA   NA   NA    2    3    4    7    8    9
4    NA   NA   NA    3    4    5    8    9   10
5    NA   NA   NA    4    5   NA    9   10   NA
6    NA    1    2   NA    6    7   NA   11   12
7     1    2    3    6    7    8   11   12   13
8     2    3    4    7    8    9   12   13   14
9     3    4    5    8    9   10   13   14   15
10    4    5   NA    9   10   NA   14   15   NA
, , layer.1

  r1c1 r1c2 r1c3 r2c1 r2c2 r2c3 r3c1 r3c2 r3c3
1   NA   NA   NA   NA    1    2   NA    6    7
2   NA   NA   NA    1    2    3    6    7    8
3   NA   NA   NA    2    3    4    7    8    9
4   NA   NA   NA    3    4    5    8    9   10
5   NA   NA   NA    4    5   NA    9   10   NA

, , layer.2

  r1c1 r1c2 r1c3 r2c1 r2c2 r2c3 r3c1 r3c2 r3c3
1   NA   NA   NA   NA    1    2   NA    6    7
2   NA   NA   NA    1    2    3    6    7    8
3   NA   NA   NA    2    3    4    7    8    9
4   NA   NA   NA    3    4    5    8    9   10
5   NA   NA   NA    4    5   NA    9   10   NA

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