How to pass an array in Psi4 plugin development?

Developer News & Discussion
1

I’m trying to develop a Psi4 plugin where I want to pass a NumPy array of doubles along with the ref_wfn, but I couldn’t find any API for that, It’s accepting wfn only.

my_wfn = psi4.core.plugin('my_plugin.so', ref_wfn)

and

extern "C" PSI_API
SharedWavefunction ddcc_psi4(SharedWavefunction ref_wfn, Options& options)
{
    int print = options.get_int("PRINT");
    return ref_wfn;
}

Even I tried to change these arguments but it’s still the same it seems there’s some abstract layer between these two codes.

2

The plugin interface is admittedly pretty limited. What you can do if you have a numpy array Py-side is to wfn.set_variable("SOME LABEL IN CAPS", my_np_array) . That’ll get converted to a psi4.core.Matrix and attached to the wfn, passed to the plugin, then you can retrieve it as wfn.variable("SOME LABEL IN CAPS").