def test_approx_spectral_function(self, fn_matrix_rtol, bsz, mpi):
fn, matrix, rtol = fn_matrix_rtol
a = matrix(2**7)
pos = fn == np.sqrt
actual_x = sum(fn(eigvalsh(a)))
approx_x = approx_spectral_function(a, fn, mpi=mpi, pos=pos,
bsz=bsz, verbosity=2)
assert_allclose(actual_x, approx_x, rtol=rtol)
def test_approx_spectral_function_ptr_ppt_lin_op(self, fn_approx_rtol,
psi_abc, psi_ab, bsz):
fn, approx, rtol = fn_approx_rtol
rho_ab_ppt = partial_transpose(psi_abc.ptr(DIMS, [0, 1]), DIMS[:-1], 0)
actual_x = sum(fn(eigvalsh(rho_ab_ppt)))
lo = lazy_ptr_ppt_linop(psi_abc, DIMS, sysa=0, sysb=1)
approx_x = approx_spectral_function(lo, fn, K=20, R=20, bsz=bsz)
assert_allclose(actual_x, approx_x, rtol=rtol)
def test_approx_spectral_function_with_v0(self, fn_matrix_rtol, bsz):
fn, matrix, rtol = fn_matrix_rtol
a = matrix(2**7)
actual_x = sum(fn(eigvals(a)))
# check un-normalized state work properly
v0 = (neel_state(7) + neel_state(7, down_first=True))
v0 = v0.A.reshape(-1)
pos = fn == np.sqrt
approx_x = approx_spectral_function(a, fn, K=20, v0=v0, pos=pos,
bsz=bsz)
assert_allclose(actual_x, approx_x, rtol=rtol)