46 lines
1.2 KiB
Python
46 lines
1.2 KiB
Python
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from __future__ import division, print_function, absolute_import
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import numpy as np
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from numpy.testing import assert_, assert_allclose
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import scipy.linalg
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from scipy.optimize import minimize
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def test_1():
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def f(x):
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return x**4, 4*x**3
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for gtol in [1e-8, 1e-12, 1e-20]:
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for maxcor in range(20, 35):
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result = minimize(fun=f, jac=True, method='L-BFGS-B', x0=20,
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options={'gtol': gtol, 'maxcor': maxcor})
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H1 = result.hess_inv(np.array([1])).reshape(1,1)
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H2 = result.hess_inv.todense()
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assert_allclose(H1, H2)
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def test_2():
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H0 = [[3, 0], [1, 2]]
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def f(x):
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return np.dot(x, np.dot(scipy.linalg.inv(H0), x))
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result1 = minimize(fun=f, method='L-BFGS-B', x0=[10, 20])
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result2 = minimize(fun=f, method='BFGS', x0=[10, 20])
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H1 = result1.hess_inv.todense()
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H2 = np.vstack((
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result1.hess_inv(np.array([1, 0])),
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result1.hess_inv(np.array([0, 1]))))
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assert_allclose(
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result1.hess_inv(np.array([1, 0]).reshape(2,1)).reshape(-1),
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result1.hess_inv(np.array([1, 0])))
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assert_allclose(H1, H2)
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assert_allclose(H1, result2.hess_inv, rtol=1e-2, atol=0.03)
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