mapdiff: Compute the difference between two maps

In ndvits: NDVI Time series extraction and analysis

Description

Compute the difference between two maps.
If the map of the standard deviation is given, the difference is divided by the standard deviation.

Usage

mapdiff(mapin, mapref, mapsd = FALSE, outfile = FALSE)

Arguments

mapin	raster map
mapref	raster map 2 (the reference)
mapsd	raster map conaining the standard deviation values. If mapsd=FALSE, the standard deviation is not taken into account while computing the difference. By default, mapsd = FALSE.
outfile	file where the difference map is saved. If outfile=FALSE, the map is not saved but only returned. By default, outfile = FALSE.

Details

If mapsd is defined :

diff = \frac{mapin - mapref}{mapsd}

else :

diff = mapin - mapref

Value

Returns the difference map

Author(s)

Romain Frelat and Bruno Gerard

Examples

ndvidirectory=paste(system.file("extdata/VITO_Mzimba",
    package="ndvits"), "/", sep="")
region="Mzimba"
filein=timetoMap(ndvidirectory,region, 2004,1,1)
filein2=timetoMap(ndvidirectory,region, 2005,1,1)

#load the maps
map04=readpartGDAL(filein)
map05=readpartGDAL(filein2)

#computing the difference of the 2 maps
diff=mapdiff(map04, map05)

#plot the difference map :
savemap(diff)

ndvits documentation built on May 2, 2019, 4:47 p.m.