def _sincinterp(M, iava, dims=None, dir=0, dtype='float64'):
"""Sinc interpolation.
"""
ncp = get_array_module(iava)
_checkunique(iava)
# create sinc interpolation matrix
nreg = M if dims is None else dims[dir]
ireg = ncp.arange(nreg)
sinc = ncp.tile(iava[:, np.newaxis], (1, nreg)) - \
ncp.tile(ireg, (len(iava), 1))
sinc = ncp.sinc(sinc)
# identify additional dimensions and create MatrixMult operator
otherdims = None
if dims is not None:
otherdims = ncp.array(dims)
otherdims = ncp.roll(otherdims, -dir)
otherdims = otherdims[1:]
Op = MatrixMult(sinc, dims=otherdims, dtype=dtype)
# create Transpose operator that brings dir to first dimension
if dir > 0:
axes = np.arange(len(dims), dtype=np.int)
axes = np.roll(axes, -dir)
dimsd = list(dims)
dimsd[dir] = len(iava)
Top = Transpose(dims, axes=axes, dtype=dtype)
T1op = Transpose(dimsd, axes=axes, dtype=dtype)
Op = T1op.H * Op * Top
return Op
def test_Transpose_3dsignal(par):
"""Dot-test and adjoint for Transpose operator for 3d signals
"""
dims = (par['ny'], par['nx'], par['nt'])
x = np.arange(par['ny']*par['nx']*par['nt']).reshape(dims) + \
par['imag'] * np.arange(par['ny']*par['nx']*par['nt']).reshape(dims)
Top = Transpose(dims=dims, axes=(2, 1, 0))
assert dottest(Top, np.prod(dims), np.prod(dims),
complexflag = 0 if par['imag'] == 0 else 3)
y = Top * x.ravel()
xadj = Top.H * y
y = y.reshape(Top.dimsd)
xadj = xadj.reshape(Top.dims)
assert_equal(x, xadj)
def test_Transpose_2dsignal(par):
"""Dot-test and adjoint for Transpose operator for 2d signals"""
dims = (par["ny"], par["nx"])
x = np.arange(par["ny"] * par["nx"]).reshape(dims) + par["imag"] * np.arange(
par["ny"] * par["nx"]
).reshape(dims)
Top = Transpose(dims=dims, axes=(1, 0), dtype=par["dtype"])
assert dottest(
Top, np.prod(dims), np.prod(dims), complexflag=0 if par["imag"] == 0 else 3
)
y = Top * x.ravel()
xadj = Top.H * y
y = y.reshape(Top.dimsd)
xadj = xadj.reshape(Top.dims)
assert_equal(x, xadj)
assert_equal(y, x.T)