## DESCRIPTION

*r.mcda.electre* is the implementation of the ELECTRE multicriteria
algorithm in GRASS GIS environment. It is one of the available tools in the
r.mcda suite. It requires as an input the list of raster representing the
criteria to be assessed in the multicriteria evaluation and the vector of
weights to be assigned. Every single cell of the GRASS region is considered
as one of the possible alternatives to evaluate and it is described with
the value assumed for the same cell by the raster used as criteria. There
are two output files. One represents the spatial distribution of the
concordance index, the other one of the discordance index. The optimal
solution is the one presenting the maximum concordance value and the minimum
discordance value at the same time.
## NOTES

The module does not standardize the raster-criteria. Therefore, they must
be prepared before by using, for example, r.mapcalc. The weights vector
is always normalized so that the sum of the weights is 1.
## REFERENCE

Roy, B. (1971) Problem and methods with multiple objective functions
Mathematical programming 1, 239-266.

Roy, B. (1990): The outranking approach and the foundations of Electre
methods , Document du LAMSADE, Paris.

Janssen R. (1994) - Multiobjective decision support for environmental
management, Kluwer Academic Publishers.

GRASS Development Team (2008)

## SEE ALSO

*r.mcda.fuzzy, r.mcda.electre, r.roughet, r.mapcalc*
## AUTHORS

Antonio Boggia - Gianluca Massei

Department of Economics and Appraisal - University of Perugia - Italy
*Last changed: $Date$*