Hello Ali, 

As far as i know DesktopGarp also use environmental variables in ASCII format, the same that you use in MaxEnt experiments... but first you need to create a layerset using the Layerset Manager that DesktopGarp installer creates in your computer. This layerset creation may take a while depending of how many layers you use and it sizes. When you create the layerset, then you can run experiments on DesktopGarp like in this manual: http://www.nhm.ku.edu/desktopgarp/UsersManual.html.

This link is about a technical manual: http://www.bio-nica.info/biblioteca/Lee2004GuideGarp.pdf

Please be patient with the Layerset Manager of DesktopGarp, it may be unstable sometimes. When you install DesktopGarp on your computer, both Layerset Manager and DesktopGarp are included in the installation process.

I hope this comments can help you, if you have some trouble please leave a message, there are also a modeling platform called "OpenModeller Desktop" that runs the GARP and GARP Best Subsets algorithms.

Greetings from Colombia, Luís Enrique.

Hello Luis,

Many thanks for your help, your suggestions were so useful and I ran the model by ascii files. But now, I have another problem. All of the outputs (.bmp format) are in one color, for example the task0.bmp is green, task1.bmp is gray, etc. Could please help me why this happened?

By the way, I've run the OpenModeller Platform and I got the suitable predictions. But, is it possible that the outputs of OpenModeller (for both GARP and GARP best subset) have different results with the outputs of the GARP Desktop software?

Best,

Hello Ali, I´m glad to hear you that your analysis works fine.

The outputs represents every run in your GARP analysis, a simple and robust way to get a better (and a few representative results) result, is better turn on the "best subset options".  When you have only the best subset results (for example 15 results of 100 runs) you can make a map algebra and make an average map for the potential distribution of the specie. Several authors state that OpenModeller outputs are different of the DesktopGarp software because OpenModeller don´t allow you to modify all the relevant options in the algorithm, this is commonly called as "Tailored software", please use the OpenModeller platform only if you can´t do it in DesktopGARP.

If you have any trouble please don´t hesitate to ask, best regards from Colombia.

Luís Enrique.

PD: In order to get good results in your potential distribution modeling, remember that you need a good quantity of points (about 80, there are no a magical number) for the best subset analysis because you use a dataset of points to create and test the GARP models, and another dataset of points for select the best subset models. 

As a fellow ENM fan, I was wondering if either of you have come across a non-ESRI solution to creating the right ascii files using R. I am trying to write Geo TIFFs as ascii, and have a script that works in R, but GARP doesn't like the file - any thoughts on what ArcGIS might be doing to the files?

You might have already figured that out. If not, here is the r code:

###RASTER to ASCII###

library(raster)

r