This calculator implements multialternative decision field theory as reported in Roe, Busemeyer, and Townsend (2001). The example R code implements the model for the similarity, attraction, and compromise effects. Pressing "run" submits the code to R and generates predictions, or you can edit the code for your own choices. Predictions appear at the bottom of the output page, and give the probability of selecting each gamble in each choice.
Full source code for the model is available, with worked examples.