parameters can be models

par_models.py

from astropy.modeling.core import Model
from astropy.modeling.models import Polynomial2D, Polynomial1D
from astropy.modeling.parameters import Parameter


class MyModel(Model):

    inputs = ('x', 'y', 't')
    outputs = ('z',)
   
    def __init__(self, c0, c1, **kwargs):
        '''
        c0, c1 are Poly models
        '''
        self.c0 = c0 # poly1d(degree=1)
        self.c1 = c1 # deg = 2

        super(MyModel, self).__init__(**kwargs)

    def evaluate(self, x, y, t):
        """
        x, y = coordinates
        t - order
        """
        p2 = Polynomial2D(1, c0_0=self.c0(t), c0_1=self.c1(t), c1_0=1)
        return p2(x,y)
   
 
c0 = Polynomial1D(1, c0=1, c1=2)
c1 = Polynomial1D(2, c0=1, c1=2, c2=3)
m = MyModel(c0, c1)
m(1, 2, 1)
# 16
m(1, 2, 2)
#40