MAD {diffeR}

Mean Absolute Deviation (MAD)

Description

Provides a method to compare the quantity difference and allocation difference between two images of the same real variable at the original resolution or at multiple resolutions. The output provides a stacked graph and an accompanying numerical table for the Mean Absolute Deviation (MAD) for the difference due to quantity, the difference due to stratum-level allocation, and difference due to pixel-level allocation. The output also indicates which image has a smaller average. A scatterplot indicating the distribution of values in relation to the 1:1 line can be produced with MADscatterplot

Usage

MAD(grid1, grid2, strata = NULL, eval = "original")

Arguments

grid1

object of class SpatRaster corresponding to the first image

grid2

object of class SpatRaster corresponding to the second image

strata

object of class SpatRaster corresponding to the mask or strata image. Zero values are taken as no data (i.e., NA)

eval

default "original", return the MAD value for the original resolution; if "multiple", return the MAD values for multiple resolutions following a geometric sequence

Value

a dataframe containing the multiples of the original resolution, the corresponding aggregated resolution, the difference due to quantity, the difference due to stratum-level allocation, and the difference due to pixel-level allocation.

References

Pontius Jr., R.G., Thontteh, O., Chen, H. 2008. Components of information for multiple resolution comparison between maps that share a real variable. Environmental and Ecological Statistics 15 (2), 111-142.

See Also

MADscatterplot

Examples

old.par <- par(no.readonly = TRUE)
grid1 <- rast(system.file("external/GRID1_INT.rst", package = "diffeR"))
grid2 <- rast(system.file("external/GRID2_INT.rst", package = "diffeR"))
strata <- rast(system.file("external/strata_int.rst", package = "diffeR"))
MAD(grid1, grid2, strata, eval = "original")
MAD(grid1, grid2, strata, eval = "multiple")

## Not run: 
veg_obs1 <- rast(system.file("external/veg_obs1.rst", package = "diffeR")) 
veg_pre1 <- rast(system.file("external/veg_pre1.rst", package = "diffeR")) 
veg_mask1 <- rast(system.file("external/veg_mask1.rst", package = "diffeR")) 
MADscatterplot(veg_obs1, veg_pre1, veg_mask1) 
MAD(veg_obs1, veg_pre1, veg_mask1, eval = "multiple") 

## End(Not run)
par(old.par)