[R-sig-Geo] dismo library: species distribution modelling and obtaining thresholds values

[Alastair Potts]

Good day all,
I am using the dismo library for species distribution modelling using a 
number of models. I would like to select different threshold levels. The 
sdm.pdf vignette only gives an example to obtain the Maximum training 
(or testing) sensitivity plus specificity threshold:
e at t[which.max(e at TPR + e at TNR)]

I was wondering how one would go about obtaining the following 
thresholds from a ModelEvaluation object:
Equal training sensitivity and specificity
Balance training omission, predicted area and threshold value
Equate entropy of thresholded and original distributions

Thanks in advance for your time,
Cheers,
Alastair Potts