Dear R community, I’m new in R (coming from SAS). If possible, I’d like to know your thoughts regarding the following. I’m working on a regression problem, where my dependent variable is a ratio of two variables (i.e. dep.var=A/B). The variable A takes a value of zero for the vast majority of observations and, of course, so does the dependent variable. I thought I should do a weighted analysis (weighting on the denominator of the ratio). I could accomplish this with a GLM (using a Poisson ~ for the dependent variable with weights=B) . However, I’d like to try a data mining approach. Specifically, I’m thinking of using a Neural Network with activation function for the target layer=exponential and error function=Poisson with weights=B. Is there any package that would allow me to do this? Alternatively, is there any other package with an algorithmic approach (as opposed the classical statistical analysis) that would allow me to accomplish what I want do? Thanks in advance for your help! Axel. [[alternative HTML version deleted]]