Hi Nan,
Thanks for running your test again and I'm glad to hear that the classifier output does no longer differ when performing training and testing multiple times using the same command-line options. Most people probably would not have noticed, since these differences are smaller than single-precision. I will take a look at the multi-class predictions (DAG, vote) and check why the output is not identical, but I suspect it's for the same reason. I would not necessary call this a bug, but reaching the precision limit of 3dsvm. That being said, the output should be identical so thank you for letting us know.
I agree, if desired (-nomodelfile) no model file should be written to disc when performing training and testing simultaneously. This was always the plan, but we rarely used this and never finished coding it up. This should not take too long - I'll update 3dsvm soon.
Jonathan
