[R-sig-Geo] data.frame methods for maxlike and maxent

[Gerardo Martin]

Hi all. I'm trying to implement some species distribution models with my 
data sets. Because of the nature of the organisms i'm working with I 
need specifically to fit models with data contained in a data.frame 
instead of providing the x,y locations to be sampled from a rasterStack.
Firstly i've found one way of doing it with dismo's maxent 
implementation, by providing a vector with 1's ans 0's, 0 values 
correspond to values extracted with randomPonints. However, I haven't 
found a way of providing the data.fame as background data, instead of 
pseudoabsences as described.
Secondly, I also want to fit a maxlike model, but haven't found if 
there's a data.frame method. Like I said, I can't do it with the 
traditional rasterStack method, because the information to fit the model 
is seasonal.

Any help is really appreciated.

Regards

Gerardo