<BODY><P>Dear all,</P>
<P>I just started running the example in the manual and there is something I do not understand. In the example NbRepPa=2 AND nb.absences=1000 (page 13,14,15). Although the data contains enough absences, we created for the porpouse of example 2 runs of pseudo absences. By setting this parameters, what is the behavior of BIOMOD?</P>
<P>That means that 2 runs of the models are made using pseudo absences (2=NbRepPA) and 3 (NbRunEval) are made using raw data with real absences (?) or...will BIOMOD feed data on real absences with PA in order to achieve data for calibration/evaluation (80 % / 20% in our example) and hence keeping prevalence constant?</P>
<P>To sum up: I would like to know if running this PA is worth when not enough data on real absences is available and whether BIOMOD does feed automatically our original dataset wiht PAs or we have to reconstruct the dataset.</P>
<P>Thank you,</P>
<P>PS: and thank you Wilfried Thuiller for the latest release of BIOMOD where finding the manual is much more easy!<BR><BR>Pep Serra Díaz <BR><BR>Despatx C1/211 <BR>Unit of Botany. <BR>Department of Animal Biology, Plant Biology and Ecology. C Builiding</P>
<P>Bioscience Faculty. Autonomous University of Barcelona.</P>
<P>08193 Cerdanyola del Vallès <BR>Spain <BR></P></BODY>