ffsim.testing

Testing utilities.

ffsim.testing.assert_allclose_up_to_global_phase(actual, desired, rtol=1e-07, atol=0, equal_nan=True, err_msg='', verbose=True)

Check if a == b * exp(i phi) for some real number phi.

Parameters:

• actual (ndarray) – A Numpy array.

• desired (ndarray) – Another Numpy array.

• rtol (float) – Relative tolerance.

• atol (float) – Absolute tolerance.

• equal_nan (bool) – If True, NaNs will compare equal.

• err_msg (str) – The error message to be printed in case of failure.

• verbose (bool) – If True, the conflicting values are appended to the error message.

Raises:

AssertionError – If a and b are not equal up to global phase, up to the specified precision.

ffsim.testing.generate_norb_nelec(norb_range)

Generate (norb, nelec) tuples for testing.

Given a range of choices for norb, generates all possible (norb, nelec) pairs.

Return type:

Iterator[tuple[int, tuple[int, int]]]

ffsim.testing.generate_norb_nelec_spin(norb_range)

Generate (norb, nelec, spin) tuples for testing.

Given a range of choices for norb, generates all possible (norb, nelec, spin) triplets.

Return type:

Iterator[tuple[int, tuple[int, int], Spin]]

ffsim.testing.generate_norb_nocc(norb_range)

Generate (norb, nocc) tuples for testing.

Given a range of choices for norb, generates all possible (norb, nocc) pairs. nocc refers to the occupation of a single spin species, so it ranges from 0 to norb.

Return type:

Iterator[tuple[int, int]]

ffsim.testing.generate_norb_spin(norb_range)

Generate (norb, spin) tuples for testing.

Given a range of choices for norb, generates all possible (norb, spin) pairs.

Return type:

Iterator[tuple[int, Spin]]

ffsim.testing.random_nelec(norb, *, seed=None)

Return a random pair of (n_alpha, n_beta) particle numbers.

Parameters:

• norb (int) – The number of spatial orbitals.

• seed – A seed to initialize the pseudorandom number generator. Should be a valid input to np.random.default_rng.

Return type:

tuple[int, int]

Returns:

The sampled pair of (n_alpha, n_beta) particle numbers.

ffsim.testing.random_occupied_orbitals(norb, nelec, *, seed=None)

Return a random pair of occupied orbitals lists.

Parameters:

• norb (int) – The number of spatial orbitals.

• nelec (int | tuple[int, int]) – Either a single integer representing the number of fermions for a spinless system, or a pair of integers storing the numbers of spin alpha and spin beta fermions.

• seed – A seed to initialize the pseudorandom number generator. Should be a valid input to np.random.default_rng.

Return type:

list[int] | tuple[list[int], list[int]]

Returns:

The sampled pair of (occ_a, occ_b) occupied orbitals lists.