test_poly_fit.py

# -*- coding: utf-8 -*-
"""
Created on Thu Oct 19 11:10:32 2017

@author: ben
"""

# poly_ref_surf test
import numpy as np
from poly_ref_surf import poly_ref_surf


degree_x=3
degree_y=3
x0=0
y0=0

xg, yg=np.meshgrid(np.arange(-1., 1., .1), np.arange(-1., 1., .1));
xg.dtype
poly_coeffs=[0, 2., 3., 4., 5., 6]
poly_deg_x=np.array([0, 1, 0, 1, 2, 0])
poly_deg_y=np.array([0, 0, 1, 1, 0, 2])

zg=np.zeros_like(xg)
for ii in np.arange(len(poly_coeffs)):
    zg=zg+poly_coeffs[ii]*(xg**poly_deg_x[ii])*(yg**poly_deg_y[ii])
zg[0,0]=-20.0    
P=poly_ref_surf(degree_x, degree_y, x0, y0, skip_constant=True)

m, rr, X2r=P.fit(xg, yg, zg, sigma_d=np.zeros_like(zg)+0.1, max_iterations=5) 
for k, ij in enumerate(zip(P.exp_x, P.exp_y)):
    this=np.where(np.logical_and(poly_deg_x==ij[0], poly_deg_y==ij[1]))[0]
    if np.array(this).size > 0:
        print('%d %d %f %f'%( ij[0], ij[1], poly_coeffs[this], m[k] ))