I’ve looked at the standard examples, and they seem to have the means and standard deviations they pass to NormalMixture either be a random variable that has a shape – so is only implicitly a vector of values – or a function of a pair of such values – so again only implicitly a vector of values. In both cases the value of the keyword argument looks to python like a singleton, so doesn’t trigger the error I see.s
This is really a problem for me, because I was trying to use the NormalMixture because the simple Mixture didn’t work for me for a different reason (see my other question).
If anyone has a work-around, I would be very grateful!