predict.enfa: Habitat Suitability Maps Built from the ENFA

predict.enfaR Documentation

Habitat Suitability Maps Built from the ENFA


predict.enfa computes habitat suitability maps using the Ecological-Niche Factor Analysis and the Mahalanobis distances method.


## S3 method for class 'enfa'
predict(object, map, nf, ...)



an object of class enfa


an object of class SpatialPixelsDataFrame.


the number of axes of specialization kept for the predictions. By default, all axes kept in object are used


further arguments passed to or from other methods


The predictions are based on the position of the niche defined by the ENFA within the multidimensional space of environmental variables. The ENFA produces row coordinates for each pixel, which are used with the function mahalanobis. For each pixel, this function computes the Mahalanobis distances from the barycentre of the niche.

Actually, the function predict.enfa is identical to the function mahasuhab, except that the habitat suitability map is computed using the axes of the ENFA, instead of the raw data.

Note that the MADIFA allows a more consistent factorial decomposition of the Mahalanobis distances.


Returns a raster map of class SpatialPixelsDataFrame.


Mathieu Basille


Clark, J.D., Dunn, J.E. and Smith, K.G. (1993) A multivariate model of female black bear habitat use for a geographic information system. Journal of Wildlife Management, 57, 519–526.

Hirzel, A.H., Hausser, J., Chessel, D. & Perrin, N. (2002) Ecological-niche factor analysis: How to compute habitat-suitability maps without absence data? Ecology, 83, 2027–2036.

See Also

mahalanobis for information on the computation of Mahalanobis distances. mahasuhab for more details on the computation of habitat suitability maps using the Mahalanobis distances. madifa for a more consistent factorial decomposition of the Mahalanobis distances


## Not run: 

map <- lynxjura$map

## We keep only "wild" indices.
locs <- lynxjura$locs
locs <- locs[slot(locs, "data")[,2]!="D",]

pr <- slot(count.points(locs, map), "data")[,1]

(enfa1 <- enfa(dudi.pca(slot(map, "data"), scannf=FALSE),
               pr, scannf = FALSE))

## Compute the prediction
pred <- predict(enfa1, map)
contour(pred, col="green", add=TRUE)
points(locs, pch = 3)

## End(Not run)

adehabitatHS documentation built on Oct. 21, 2022, 5:07 p.m.