Okay, so I see that the the line in their code
@theano.compile.ops.as_op(itypes=[t.dscalar,t.dscalar,t.dscalar],otypes=[t.dvector])
is probably what helps with this. I am still getting an error, however, and a more complex use case than this that requires some more follow up. I have the whole MCMC process wrapped up in a Python class (because I have lots of parameters that aren’t part of the MCMC that have to go into the model). I have no intuition as to how this wrapper function can be written to handle other non-Theano inputs. If Theano makes it so difficult to simply print out an individual realization of the tensor values, then I should probably just do what I know needs to be done - decouple the Fortran from txt I/O and get that working as its own module in Python before trying the MCMC.