[R-sig-Geo] raster::predict: more than one single output
Agustin Lobo
alobolistas at gmail.com
Sat Sep 24 11:48:58 CEST 2011
I'm using raster::predict using predict.lda():
> srndpc20000lda <- lda(srndpcclasses[,1:5],srndpcclasses[,37])
> PCAtoMedian_6yrsclass20000 <- predict(object=PCAtoMedian_6yrs,model=srndpc20000lda)
> PCAtoMedian_6yrsclass20000
class : RasterLayer
dimensions : 1289, 1289, 1661521 (nrow, ncol, ncell)
resolution : 0.008928571, 0.008928571 (x, y)
extent : 30.99554, 42.50446, 1.495536, 13.00446 (xmin, xmax, ymin, ymax)
coord. ref. : +proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs +towgs84=0,0,0
values : in memory
min value : 1
max value : 4
But I would also need the rest of the output provided by
predict.lda(), in particular a layer with the posterior
probabilities to mask out those pixels which do not have a high
probability for any of the classes.
>From the help page of MASS::predict.lda():
Value
a list with components
class The MAP classification (a factor)
posterior posterior probabilities for the classes
x the scores of test cases on up to dimen discriminant variables
As far as I understand, only "class" is returned by raster::predict.
Am I wrong and there is actually a way to get the posteriors?
Otherwise, could that be added in the future?
Thanks
Agus
More information about the R-sig-Geo
mailing list