Pass a 2D vector to a parameter

[xyyrly]

Dear Team:

I am trying to process interfacial current density calculated by DFN model to my thermal model as a parameter, which should be a 2D spatio-temporal vector. I found an example like this:
current_interpolant = pybamm.Interpolant(drive_cycle[:, 0], drive_cycle[:, 1], pybamm.t)
param["Current function [A]"] = current_interpolant

But how does pybamm.Interpolant work on 2D? And how can I set the spatial positions to interpolate?(can I define and use a SpatialVariable like "x_p"?）

Thank you for your time~

[valentinsulzer]

See https://github.com/pybamm-team/PyBaMM/blob/develop/tests/unit/test_expression_tree/test_interpolant.py#L93-L108

[xyyrly]

Thank you very much@tinosulzer
But I am still confused about how to set var1 and var2. As my understand, one of them I can use pybamm.t for the discretised time vector, but how to set the space vector?
It looks not correct when I set as:
x = (Xn[:,0],np.linspace(0, 1, 10))#shape(20,10)
z = J_V#shape(20,10)
x_n = pybamm.SpatialVariable("x_n", domain=["negative electrode"], coord_sys="cartesian")
param = pybamm.ParameterValues(
{
"Negative electrode volumetric interfacial current density [A.m-3]": pybamm.Interpolant(x, z, (x_n, pybamm.t), interpolator="linear"),
}
)