def test_2D_fitting(self):
xdata = np.random.randint(-10, 11, size=(2, 400))
zdata = 2.5*xdata[0]**2 + 7.0*xdata[1]**2
a = Parameter()
b = Parameter()
x = Variable()
y = Variable()
new = a*x**2 + b*y**2
fit = Fit(new, xdata[0], xdata[1], zdata)
# result = fit.scipy_func(fit.xdata, [2, 3])
result = fit.model(xdata[0], xdata[1], 2, 3)
for arg_name, name in zip(('x', 'y', 'a', 'b'), inspect_sig.signature(fit.model).parameters):
self.assertEqual(arg_name, name)
fit_result = fit.execute()
self.assertIsInstance(fit_result, FitResults)
