Function py_gpfa_transform 

pub(crate) fn py_gpfa_transform(
    py: Python<'_>,
    new_trains: Vec<PyReadonlyArray1<'_, i32>>,
    c: PyReadonlyArray1<'_, f64>,
    d: PyReadonlyArray1<'_, f64>,
    r: PyReadonlyArray1<'_, f64>,
    tau: PyReadonlyArray1<'_, f64>,
    n_latents: usize,
    bin_ms: f64,
    dt: f64,
) -> Py<PyArray1<f64>>