76 lines
1.8 KiB
Python
76 lines
1.8 KiB
Python
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import numpy as np
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from numpy.testing import assert_equal, assert_allclose
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from scipy.integrate import odeint
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import scipy.integrate._test_odeint_banded as banded5x5
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def rhs(y, t):
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dydt = np.zeros_like(y)
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banded5x5.banded5x5(t, y, dydt)
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return dydt
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def jac(y, t):
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n = len(y)
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jac = np.zeros((n, n), order='F')
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banded5x5.banded5x5_jac(t, y, 1, 1, jac)
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return jac
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def bjac(y, t):
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n = len(y)
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bjac = np.zeros((4, n), order='F')
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banded5x5.banded5x5_bjac(t, y, 1, 1, bjac)
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return bjac
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JACTYPE_FULL = 1
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JACTYPE_BANDED = 4
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def check_odeint(jactype):
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if jactype == JACTYPE_FULL:
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ml = None
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mu = None
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jacobian = jac
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elif jactype == JACTYPE_BANDED:
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ml = 2
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mu = 1
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jacobian = bjac
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else:
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raise ValueError("invalid jactype: %r" % (jactype,))
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y0 = np.arange(1.0, 6.0)
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# These tolerances must match the tolerances used in banded5x5.f.
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rtol = 1e-11
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atol = 1e-13
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dt = 0.125
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nsteps = 64
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t = dt * np.arange(nsteps+1)
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sol, info = odeint(rhs, y0, t,
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Dfun=jacobian, ml=ml, mu=mu,
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atol=atol, rtol=rtol, full_output=True)
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yfinal = sol[-1]
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odeint_nst = info['nst'][-1]
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odeint_nfe = info['nfe'][-1]
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odeint_nje = info['nje'][-1]
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y1 = y0.copy()
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# Pure Fortran solution. y1 is modified in-place.
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nst, nfe, nje = banded5x5.banded5x5_solve(y1, nsteps, dt, jactype)
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# It is likely that yfinal and y1 are *exactly* the same, but
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# we'll be cautious and use assert_allclose.
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assert_allclose(yfinal, y1, rtol=1e-12)
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assert_equal((odeint_nst, odeint_nfe, odeint_nje), (nst, nfe, nje))
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def test_odeint_full_jac():
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check_odeint(JACTYPE_FULL)
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def test_odeint_banded_jac():
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check_odeint(JACTYPE_BANDED)
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