ICvectorfields (version 0.1.2)

SubgridMoransI: Compute statistics for subgrids

Description

Functions that facilitate calculation of statistics at the sub-grid level. These may be useful for drivers of movement speed or direction if used in tandem with DispField, DispFieldST, or DispFieldSTall.

Usage

SubgridMoransI(inputrast1, factv1, facth1, rad1 = 1)
SubgridStats(inputrast1, factv1, facth1, statistic = "var")

Arguments

inputrast1

a raster as produced by terra::rast

factv1

an odd integer for the vertical dimension of sub-grids

facth1

an odd integer for the horizontal dimension of sub-grids

rad1

an integer indicating the neighbourhood radius for Moran's I statistic calculations in rows/columns. Any cell within a distance of rad1 cells of the focal cell is considered to be in its neighbourhood.

statistic

desired output statistic: It should be one of "mean", "var", or "sum". Default setting is var.

Value

A data frame is returned with the following column names: rowcent, colcent, frowmin, frowmax, fcolmin, fcolmax, and a column for the output statistic.

Details

Note that when using radius to define the neighbourhood in Moran's I calculations, a radius of one corresponds to the rook's neibhourhood. Values that are NA or Inf are not included in calculations of the Moran's I statistic nor in any of the other statistics that can be computed.

See Also

DispStats and DispMoransIfor functions that compute statistics at presumed source or sink locations in each region of interest.

Examples

# NOT RUN {
(TestMat <- matrix(c(1, 0, 1, 0, 1,
                     0, 1, 0, 1, 0,
                     1, 0, 1, 0, 1,
                     0, 1, 0, 1, 0,
                     1, 0, 1, 0, 1),
                    nrow = 5))

TestRast <- terra::rast(TestMat)
terra::plot(TestRast)

SubgridMoransI(TestRast, factv1 = 5, facth1 = 5, rad1 = 1)
# using rad1 = 1 is equivalent to using the rooks neighbourhood
# and so the output should be -1.

(TestMat <- matrix(c(1, 0, 1, 0, 1,
                    0, 1, 0, 1, 0,
                    1, 0, 1, 0, 1,
                    0, 1, 0, 1, 0,
                    1, 0, 1, 0, 1),
                    nrow = 5))

TestRast <- terra::rast(TestMat)
terra::plot(TestRast)

SubgridStats(TestRast, factv1 = 5, facth1 = 5, statistic = "mean")
SubgridStats(TestRast, factv1 = 5, facth1 = 5, statistic = "var")
SubgridStats(TestRast, factv1 = 5, facth1 = 5, statistic = "sum")

# }