[Biomod-commits] Prediction Range Error in projections

[Wilfried Thuiller]

Dear Pep,

There are some functions (MDA, ANN, MARS, Randomforest) which sometimes 
give negative probabilities or values higher than 1. We have fixed that 
problem with a rescaling function which constrain the probabilities 
between 0 and 1.
It seems the problem is coming from here.

Here are some comments and additional questions to make sure I 
understand the problem correctly:

- Put MDA, ANN, MARS and RandomForest as FALSE. It should work now, is 
not it?
- Are you sure about the quality of your climate change scenarios? To 
make sure, make a pairwise plot comparing each variable under current 
conditions against the future ones. Given the linearity of climate 
change scenarios, you should have very good correlations between current 
and future variables. Do you have this?

All the best
Wilfried




PEP Serra Diaz a écrit :
>
>
> Dear BIOMODers,
>
> I tried to make projections in future climate scenarios. To do so, I 
> used the Projection function but this error message appeared:
>
>                 Projection(Proj = a1.quil, Proj.name='A1FI', GLM = T, 
> GBM = T, GAM = T, CTA = T, ANN = T, SRE = T, Perc025=T, Perc05=F, MDA 
> =T, MARS = T, RF = T, BinRoc=T, BinKappa=T, BinTSS=T, FiltRoc=F, 
> FiltKappa=F, FiltTSS=F, repetition.models=T)
>
> Error en if (min(DataToRescale) < min(DataToRescale) - MinMaxRange * 
> 0.1) warning("Prediction Range is more than 10% smaller than 
> calibration range: Prediction quality might be affected! \n") :
>   valor ausente donde TRUE/FALSE es necesario [translation: TRUE 
> /FALSE value is absent when necessary]
>
> - I checked that the names of the explanatory variables where the same 
> than in the calibration procedure, but everything seems to be ok 
> according to what it is stated in the manual. In addition I don't 
> understand the meaning of Prediction Range.
>
> Any clue out there?
>
> Thanks
>
>
> Pep Serra Díaz
>
> Despatx C1/211
> Unitat de Botànica.
> Departament de Biologia Animal, Biologia Vegetal i Ecologia.
> Facultat de Biociències. Edifici C. Campus de Bellaterra
> Universitat Autònoma de Barcelona
> 08193 Cerdanyola del Vallès
> Spain
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Biomod-commits mailing list
> Biomod-commits at lists.r-forge.r-project.org
> https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/biomod-commits
>   

-- 
--
Wilfried Thuiller
Laboratoire d'Ecologie Alpine, UMR-CNRS 5553
Université J. Fourier
BP 53, 38041 Grenoble Cedex 9, France
Tel: +33 (0)4 76 63 54 53
Fax: +33 (0)4 76 51 42 79

Email: wilfried.thuiller at ujf-grenoble.fr
Home page: http://www.will.chez-alice.fr
Website: http://www-leca.ujf-grenoble.fr/equipes/tde.htm

FP6 European MACIS project: http://www.macis-project.net
FP6 European EcoChange project: http://www.ecochange-project.eu

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.r-forge.r-project.org/pipermail/biomod-commits/attachments/20090929/b7eb2dae/attachment.htm