def test_not_last_axis_success(self):
ar, ai = np.random.random((2, 16, 8, 32))
a = ar + 1j*ai
axes = (-2,)
# Should not raise error
fft.irfftn(a, axes=axes)
def test_not_last_axis_success(self):
ar, ai = np.random.random((2, 16, 8, 32))
a = ar + 1j * ai
axes = (-2, )
# Should not raise error
fft.irfftn(a, axes=axes)
def __compute_contrasts(im, sigma_g1s, sigma_g2s):
"""
Compute the contrasts for measuring contrast enhancement. This computes c_σ_g₁ from [1] for each
pixel across all of the frequencies, which is defined as:
c_σ_g₁(x,y) = O(x,y) / S(x,y) for each σ_g1 (eq 22)
O(x,y) = C(x,y) - S(x,y) (eq 19)
C(x,y) = im ⊗ g₁(x,y) (eq 20)
S(x,y) = im ⊗ g₂(x,y) (eq 21)
σ_g₁ = 2 log(1/M²)/(1-M²) /𝜈² for 𝜈∈[0,π] (eq 23)
𝜈 = 72π/80, 69π/80, ..., 6π/80, 3π/80
g(x,y) = exp(-1/(2σ²(x²+y²))) - a Gaussian with σ_g1 given above or σ_g₂=M*σ_g₁
where ⊗ is a convolution. All of these are fairly easily expanded to any number of dimensions by
using a higher-dimensional Gaussian kernel (actually a 1D Gaussian kernel is applied along each
dimension).
The g₁ and g₂ kernels are given for all σs along with the image.
REFERENCES:
1. Sen D and Pal S K, May 2011, "Automatic Exact Histogram Specification for Contrast
Enhancement and Visual System Based Quantitative Evaluation", IEEE Transactions on Image
Processing, 20(5):1211-1220.
"""
from .util import EPS
from scipy.ndimage import fourier_gaussian
contrasts = empty(im.shape + (len(sigma_g1s), ))
rfftn, irfftn, empty_aligned = __get_rfft()
im = rfftn(im.astype(float, copy=False))
temp = empty_aligned(im.shape, im.dtype)
for i, (sigma_g1, sigma_g2) in enumerate(zip(sigma_g1s, sigma_g2s)):
# Using real-space correlations (also need to remove rfftn() above but keep the astype)
# The real-space correlations produce lower values
#center = im if g_1.size == 1 else ndi.gaussian_filter(im, sigma_g1, truncate=3)
#surround = ndi.gaussian_filter(im, sigma_g2, output=temp, truncate=3)
center = irfftn(
fourier_gaussian(im, sigma_g1, im.shape[-1], output=temp))
surround = irfftn(
fourier_gaussian(im, sigma_g2, im.shape[-1], output=temp))
surround[surround == 0] = EPS
contrast = contrasts[..., i]
subtract(center, surround, contrast)
contrast /= surround
#abs(contrast, contrast) # norm will automatically take the absolute value for us
return contrasts
def test_energy(self):
tol = 1e-10
L = 2 + rand() # domain length
a = 3 + rand() # amplitude of force
E = 4 + rand() # Young's Mod
for res in [4, 8, 16]:
area_per_pt = L / res
x = np.arange(res) * area_per_pt
force = a * np.cos(2 * np.pi / L * x)
# theoretical FFT of force
Fforce = np.zeros_like(x)
Fforce[1] = Fforce[-1] = res / 2. * a
# theoretical FFT of disp
Fdisp = np.zeros_like(x)
Fdisp[1] = Fdisp[-1] = res / 2. * a / E * L / (np.pi)
# verify consistency
hs = PeriodicFFTElasticHalfSpace(res, E, L)
fforce = rfftn(force.T).T
fdisp = hs.greens_function * fforce
self.assertTrue(
Tools.mean_err(fforce, Fforce, rfft=True) < tol,
"fforce = \n{},\nFforce = \n{}".format(fforce.real, Fforce))
self.assertTrue(
Tools.mean_err(fdisp, Fdisp, rfft=True) < tol,
"fdisp = \n{},\nFdisp = \n{}".format(fdisp.real, Fdisp))
# Fourier energy
E = .5 * np.dot(Fforce / area_per_pt, Fdisp) / res
disp = hs.evaluate_disp(force)
e = hs.evaluate_elastic_energy(force, disp)
kdisp = hs.evaluate_k_disp(force)
self.assertTrue(
abs(disp - irfftn(kdisp.T).T).sum() < tol,
("disp = {}\n"
"ikdisp = {}").format(disp,
irfftn(kdisp.T).T))
ee = hs.evaluate_elastic_energy_k_space(fforce, kdisp)
self.assertTrue(
abs(e - ee) < tol,
"violate Parseval: e = {}, ee = {}, ee/e = {}".format(
e, ee, ee / e))
self.assertTrue(
abs(E - e) < tol,
"theoretical E = {}, computed e = {}, diff(tol) = {}({})".
format(E, e, E - e, tol))
def getCovMatrix(IQdata, lags=100, hp=False): # 0: <I1I2> # 1: <Q1Q2> # 2: <I1Q2> # 3: <Q1I2> # 4: <Squeezing> Magnitude # 5: <Squeezing> Phase lags = int(lags) I1 = np.asarray(IQdata[0]) Q1 = np.asarray(IQdata[1]) I2 = np.asarray(IQdata[2]) Q2 = np.asarray(IQdata[3]) CovMat = np.zeros([10, lags * 2 + 1]) start = len(I1) - lags - 1 stop = len(I1) + lags sI1 = np.array(I1.shape) shape0 = sI1 * 2 - 1 fshape = [_next_regular(int(d)) for d in shape0] # padding to optimal size for FFTPACK fslice = tuple([slice(0, int(sz)) for sz in shape0]) # Do FFTs and get Cov Matrix fftI1 = rfftn(I1, fshape) fftQ1 = rfftn(Q1, fshape) fftI2 = rfftn(I2, fshape) fftQ2 = rfftn(Q2, fshape) rfftI1 = rfftn(I1[::-1], fshape) # there should be a simple relationship to fftI1 rfftQ1 = rfftn(Q1[::-1], fshape) rfftI2 = rfftn(I2[::-1], fshape) rfftQ2 = rfftn(Q2[::-1], fshape) CovMat[0, :] = irfftn((fftI1 * rfftI2))[fslice].copy()[start:stop] / fshape CovMat[1, :] = irfftn((fftQ1 * rfftQ2))[fslice].copy()[start:stop] / fshape CovMat[2, :] = irfftn((fftI1 * rfftQ2))[fslice].copy()[start:stop] / fshape CovMat[3, :] = irfftn((fftQ1 * rfftI2))[fslice].copy()[start:stop] / fshape psi = (1j * (CovMat[2, :] + CovMat[3, :]) + (CovMat[0, :] - CovMat[1, :])) CovMat[4, :] = abs(psi) CovMat[5, :] = np.angle(psi) CovMat[6, :] = irfftn((fftI1 * rfftI1))[fslice].copy()[start:stop] / fshape CovMat[7, :] = irfftn((fftQ1 * rfftQ1))[fslice].copy()[start:stop] / fshape CovMat[8, :] = irfftn((fftI2 * rfftI2))[fslice].copy()[start:stop] / fshape CovMat[9, :] = irfftn((fftQ2 * rfftQ2))[fslice].copy()[start:stop] / fshape return CovMat
def convolve_3d_same(cube, psf, compute_fourier=True):
"""
Convolve a 3D cube with PSF & LSF.
PSF can be the PSF data or its Fourier transform.
if compute_fourier then compute the fft transform of the PSF.
if False then assumes that the fft is given.
This convolution has edge effects (and is slower when using numpy than pyfftw).
cube: The cube we want to convolve
psf: The Point Spread Function or its Fast Fourier Transform
"""
size = np.array(np.shape(cube)[slice(0, 3)])
#import ipdb; ipdb.set_trace()
if compute_fourier:
fft_psf = rfftn(psf, axes=[0, 1, 2])
else:
fft_psf = psf
fft_img = rfftn(cube, axes=[0, 1, 2])
# Convolution
#fft_cube = np.real(fftshift(irfftn(fft_img * fft_psf, size=size, axes=[0, 1, 2]), axes=[0, 1, 2]))
convolved_cube = np.real(
fftshift(irfftn(fft_img * fft_psf, axes=[0, 1, 2]), axes=[0, 1, 2]))
return convolved_cube, fft_psf, fft_img
def ifftn_mpi(fu, u):
"""ifft in three directions using mpi.
Need to do ifft in reversed order of fft
"""
if num_processes == 1:
#u[:] = irfft(ifft(ifft(fu, axis=0), axis=2), axis=1)
u[:] = irfftn(fu, axes=(0,2,1))
return
# Do first owned direction
Uc_hat[:] = ifft(fu, axis=0)
# Communicate all values
comm.Alltoall([Uc_hat, MPI.DOUBLE_COMPLEX], [U_mpi, MPI.DOUBLE_COMPLEX])
for i in range(num_processes):
Uc_hatT[:, :, i*Np:(i+1)*Np] = U_mpi[i]
#for i in range(num_processes):
# if not i == rank:
# comm.Sendrecv_replace([Uc_send[i], MPI.DOUBLE_COMPLEX], i, 0, i, 0)
# Uc_hatT[:, :, i*Np:(i+1)*Np] = Uc_send[i]
# Do last two directions
#u[:] = irfft(ifft(Uc_hatT, axis=2), axis=1)
u[:] = irfft2(Uc_hatT, axes=(2,1))
def compute(a, b):
"""
Compute an optimal displacement between two ndarrays.
Finds the displacement between two ndimensional arrays. Arrays must be
of the same size. Algorithm uses a cross correlation, computed efficiently
through an n-dimensional fft.
Parameters
----------
a : ndarray
The first array
b : ndarray
The second array
"""
from numpy.fft import rfftn, irfftn
from numpy import unravel_index, argmax
# compute real-valued cross-correlation in fourier domain
s = a.shape
f = rfftn(a)
f *= rfftn(b).conjugate()
c = abs(irfftn(f, s))
# find location of maximum
inds = unravel_index(argmax(c), s)
# fix displacements that are greater than half the total size
pairs = zip(inds, a.shape)
# cast to basic python int for serialization
adjusted = [int(d - n) if d > n // 2 else int(d) for (d, n) in pairs]
return Displacement(adjusted)
def fft_gaussian_filter(img, sigma):
"""FFT gaussian convolution.
Parameters
----------
img : ndarray
Image to convolve with a gaussian kernel
sigma : int or sequence
The sigma(s) of the gaussian kernel in _real space_
Returns
-------
filt_img : ndarray
The filtered image
"""
# This doesn't help agreement but it will make things faster
# pull the shape
s1 = np.array(img.shape)
# s2 = np.array([int(s * 4) for s in _normalize_sequence(sigma, img.ndim)])
shape = s1 # + s2 - 1
# calculate a nice shape
fshape = [next_fast_len(int(d)) for d in shape]
# pad out with reflection
pad_img = fft_pad(img, fshape, "reflect")
# calculate the padding
padding = tuple(_calc_pad(o, n) for o, n in zip(img.shape, pad_img.shape))
# so that we can calculate the cropping, maybe this should be integrated
# into `fft_pad` ...
fslice = tuple(
slice(s, -e) if e != 0 else slice(s, None) for s, e in padding)
# fourier transfrom and apply the filter
kimg = rfftn(pad_img, fshape)
filt_kimg = fourier_gaussian(kimg, sigma, pad_img.shape[-1])
# inverse FFT and return.
return irfftn(filt_kimg, fshape)[fslice]
def c2f(self, x_h):
'see class doc'
assert x_h.shape == (self.n*2, self.n*2, self.n+1)
x_h[:,:,[0,-1]] *= sqrt(2)
x = irfftn(self.extend(x_h)) * self.n32**3
x_h[:,:,[0,-1]] /= sqrt(2)
return x
def get_V(self):
"""
get_V - computes and stores the gravitational potential
Parameters
----------
None.
Returns
-------
None.
"""
if not self.gpu:
self.rho[...] = conj_square(self.psi)
self.fourier_grid[...] = fft.rfftn(self.rho)
ft_inv_laplace(self.fourier_grid)
self.fourier_grid *= 4 * np.pi * G
self.V[...] = fft.irfftn(self.fourier_grid)
self.V[...] += self.lam * self.rho**2
else:
self.g_conj_square(self.g_psi, self.g_rho)
cufft.cufftExecD2Z(self.rho_plan, self.g_rho.ptr,
self.g_fourier.ptr)
self.g_fourier /= self.psi.shape[0]**3
self.g_pot_func(self.g_fourier,
np.float64(4 * np.pi * G / self.N),
np.int64(self.fourier_grid.shape[0]),
np.int64(self.fourier_grid.shape[1]),
np.int64(self.fourier_grid.shape[2]),
block=(8, 8, 8),
grid=tuple([(i + 7) / 8
for i in self.psi_hat.shape]))
cufft.cufftExecZ2D(self.inv_plan, self.g_fourier.ptr, self.g_V.ptr)
self.g_V += self.lam * self.g_rho**2
def hg_conv(f, g): ub = tuple(array(f.shape) + array(g.shape) - 1); fh = rfftn(cpad(f,ub)); gh = rfftn(cpad(g,ub)); res = ifftshift(irfftn(fh * sp.conjugate(gh))); del fh, gh; return res;
def computeDisplacement(arry1, arry2):
"""
Compute an optimal displacement between two ndarrays.
Finds the displacement between two ndimensional arrays. Arrays must be
of the same size. Algorithm uses a cross correlation, computed efficiently
through an n-dimensional fft.
Parameters
----------
arry1 : ndarray
The first array
arry2 : ndarray
The second array
"""
from numpy.fft import rfftn, irfftn
from numpy import unravel_index, argmax
# compute real-valued cross-correlation in fourier domain
s = arry1.shape
f = rfftn(arry1)
f *= rfftn(arry2).conjugate()
c = abs(irfftn(f, s))
# find location of maximum
inds = unravel_index(argmax(c), s)
# fix displacements that are greater than half the total size
pairs = zip(inds, arry1.shape)
# cast to basic python int for serialization
adjusted = [int(d - n) if d > n // 2 else int(d) for (d, n) in pairs]
return adjusted
def customfftconvolve(in1, in2, mode="full", types=('','')):
""" Pretty much the same as original fftconvolve, but supports
having operands as fft already
"""
in1 = asarray(in1)
in2 = asarray(in2)
if in1.ndim == in2.ndim == 0: # scalar inputs
return in1 * in2
elif not in1.ndim == in2.ndim:
raise ValueError("in1 and in2 should have the same dimensionality")
elif in1.size == 0 or in2.size == 0: # empty arrays
return array([])
s1 = array(in1.shape)
s2 = array(in2.shape)
complex_result = False
#complex_result = (np.issubdtype(in1.dtype, np.complex) or
# np.issubdtype(in2.dtype, np.complex))
shape = s1 + s2 - 1
if mode == "valid":
_check_valid_mode_shapes(s1, s2)
# Speed up FFT by padding to optimal size for FFTPACK
fshape = [_next_regular(int(d)) for d in shape]
fslice = tuple([slice(0, int(sz)) for sz in shape])
if not complex_result:
if types[0] == 'fft':
fin1 = in1#_unfold_fft(in1, fshape)
else:
fin1 = rfftn(in1, fshape)
if types[1] == 'fft':
fin2 = in2#_unfold_fft(in2, fshape)
else:
fin2 = rfftn(in2, fshape)
ret = irfftn(fin1 * fin2, fshape)[fslice].copy()
else:
if types[0] == 'fft':
fin1 = _unfold_fft(in1, fshape)
else:
fin1 = fftn(in1, fshape)
if types[1] == 'fft':
fin2 = _unfold_fft(in2, fshape)
else:
fin2 = fftn(in2, fshape)
ret = ifftn(fin1 * fin2)[fslice].copy()
if mode == "full":
return ret
elif mode == "same":
return _centered(ret, s1)
elif mode == "valid":
return _centered(ret, s1 - s2 + 1)
else:
raise ValueError("Acceptable mode flags are 'valid',"
" 'same', or 'full'.")
def GaussianRandomInitializer(gridShape, sigma=0.2, seed=None, slipSystem=None, slipPlanes=None, slipDirections=None, vacancy=None, smectic=None):
oldgrid = copy.copy(gridShape)
if len(gridShape) == 1:
gridShape = (128,)
if len(gridShape) == 2:
gridShape = (128,128)
if len(gridShape) == 3:
gridShape = (128,128,128)
""" Returns a random initial set of fields of class type PlasticityState """
if slipSystem=='gamma':
state = SlipSystemState.SlipSystemState(gridShape,slipPlanes=slipPlanes,slipDirections=slipDirections)
elif slipSystem=='betaP':
state = SlipSystemBetaPState.SlipSystemState(gridShape,slipPlanes=slipPlanes,slipDirections=slipDirections)
else:
if vacancy is not None:
state = VacancyState.VacancyState(gridShape,alpha=vacancy)
elif smectic is not None:
state = SmecticState.SmecticState(gridShape)
else:
state = PlasticityState.PlasticityState(gridShape)
field = state.GetOrderParameterField()
Ksq_prime = FourierSpaceTools.FourierSpaceTools(gridShape).kSq * (-sigma**2/4.)
if seed is None:
seed = 0
n = 0
random.seed(seed)
Ksq = FourierSpaceTools.FourierSpaceTools(gridShape).kSq.numpy_array()
for component in field.components:
temp = random.normal(scale=gridShape[0],size=gridShape)
ktemp = fft.rfftn(temp)*(sqrt(pi)*sigma)**len(gridShape)*exp(-Ksq*sigma**2/4.)
field[component] = numpy.real(fft.irfftn(ktemp))
#field[component] = GenerateGaussianRandomArray(gridShape, temp ,sigma)
n += 1
"""
t, s = LoadState("2dstate32.save", 0)
for component in field.components:
for j in range(0,32):
field[component][:,:,j] = s.betaP[component].numpy_array()
"""
## To make seed consistent across grid sizes and convergence comparison
gridShape = copy.copy(oldgrid)
if gridShape[0] != 128:
state = ResizeState(state,gridShape[0],Dim=len(gridShape))
state = ReformatState(state)
state.ktools = FourierSpaceTools.FourierSpaceTools(gridShape)
return state
def density(self):
self._transformer.density()
fft_grid = rfftn(self.xmap.array)
fft_grid[self._fft_mask] = 0
grid = irfftn(fft_grid)
if self.b_add is not None:
pass
self.xmap.array[:] = grid.real
def __call__(self, image):
assert alltrue(
image.shape == self._expected_shape
), "Shape of image to be convolved is not correct. Re-run setup."
ret = irfftn(rfftn(image, self._fshape) * self._psf_fft,
self._fshape)[self._fslice].copy()
return _centered(ret, self._expected_shape)
def getCovMatrix(I1, Q1, I2, Q2, lags=20):
# calc <I1I2>, <I1Q2>, Q1I2, Q1Q2
lags = int(lags)
I1 = np.asarray(I1)
Q1 = np.asarray(Q1)
I2 = np.asarray(I2)
Q2 = np.asarray(Q2)
CovMat = np.zeros([6, lags*2-1])
start = len(I1*2-1)-lags
stop = len(I1*2-1)-1+lags
sI1 = np.array(I1.shape)
sQ2 = np.array(Q2.shape)
shape = sI1 + sQ2 - 1
HPfilt = (int(sI1/(lags*4))) # smallest features visible is lamda/4
fshape = [_next_regular(int(d)) for d in shape] # padding to optimal size for FFTPACK
fslice = tuple([slice(0, int(sz)) for sz in shape])
# Do FFTs and get Cov Matrix
fftI1 = rfftn(I1, fshape)
fftQ1 = rfftn(Q1, fshape)
fftI2 = rfftn(I2, fshape)
fftQ2 = rfftn(Q2, fshape)
rfftI1 = rfftn(I1[::-1], fshape)
rfftQ1 = rfftn(Q1[::-1], fshape)
rfftI2 = rfftn(I2[::-1], fshape)
rfftQ2 = rfftn(Q2[::-1], fshape)
# filter frequencies outside the lags range
fftI1 = np.concatenate((np.zeros(HPfilt), fftI1[HPfilt:]))
fftQ1 = np.concatenate((np.zeros(HPfilt), fftQ1[HPfilt:]))
fftI2 = np.concatenate((np.zeros(HPfilt), fftI2[HPfilt:]))
fftQ2 = np.concatenate((np.zeros(HPfilt), fftQ2[HPfilt:]))
# filter frequencies outside the lags range
rfftI1 = np.concatenate((np.zeros(HPfilt), rfftI1[HPfilt:]))
rfftQ1 = np.concatenate((np.zeros(HPfilt), rfftQ1[HPfilt:]))
rfftI2 = np.concatenate((np.zeros(HPfilt), rfftI2[HPfilt:]))
rfftQ2 = np.concatenate((np.zeros(HPfilt), rfftQ2[HPfilt:]))
CovMat[0, :] = (irfftn((fftI1*rfftI2))[fslice].copy()[start:stop] / len(fftI1)) # 0: <I1I2>
CovMat[1, :] = (irfftn((fftQ1*rfftQ2))[fslice].copy()[start:stop] / len(fftI1)) # 1: <Q1Q2>
CovMat[2, :] = (irfftn((fftI1*rfftQ2))[fslice].copy()[start:stop] / len(fftI1)) # 2: <I1Q2>
CovMat[3, :] = (irfftn((fftQ1*rfftI2))[fslice].copy()[start:stop] / len(fftI1)) # 3: <Q1I2>
CovMat[4, :] = (abs(1j*(CovMat[2, :]+CovMat[3, :]) + (CovMat[0, :] - CovMat[1, :]))) # 4: <Squeezing> Magnitude
CovMat[5, :] = np.angle(1j*(CovMat[2, :]+CovMat[3, :]) + (CovMat[0, :] - CovMat[1, :])) # 5: <Squeezing> Angle
return CovMat
def extended_source_image(self, ideal_image):
# Convolve
assert np.alltrue(ideal_image.shape == self._expected_shape), "Shape of image to be convolved is not correct."
ret = irfftn(rfftn(ideal_image, self._fshape) * self._psf_fft, self._fshape)[self._fslice].copy()
conv = _centered(ret, self._expected_shape)
return conv
def GenerateGaussianRandomArray(gridShape, temp, sigma):
dimension = len(gridShape)
if dimension == 1:
kfactor = fromfunction(lambda kz: exp(-0.5*(sigma*kz)**2),[gridShape[0]/2+1,])
ktemp = fft.rfft(temp)
ktemp *= kfactor
data = fft.irfft(ktemp)
elif dimension == 2:
X,Y = gridShape
kfactor = fromfunction(lambda kx,ky: exp(-0.5*sigma**2*((kx*(kx<X/2)+(X-kx)*(kx>=X/2))**2+ky**2)),[X,Y/2+1])
ktemp = fft.rfftn(temp)
ktemp *= kfactor
data = fft.irfftn(ktemp)
elif dimension == 3:
X,Y,Z = gridShape
kfactor = fromfunction(lambda kx,ky,kz: exp(-0.5*sigma**2*( (kx*(kx<X/2)+(X-kx)*(kx>=X/2))**2 + \
(ky*(ky<Y/2)+(Y-ky)*(ky>=Y/2))**2 + kz**2)),[X,Y,Z/2+1])
ktemp = fft.rfftn(temp)
ktemp *= kfactor
data = fft.irfftn(ktemp)
return data
def fftconvolve(in1, in2):
"""Convolve two N-dimensional arrays using FFT.
This is a modified version of the scipy.signal.fftconvolve.
The new feature is derived from the fftconvolve algorithm used in the IDL package.
Parameters
----------
in1 : array_like
First input.
in2 : array_like
Second input. Should have the same number of dimensions as `in1`;
if sizes of `in1` and `in2` are not equal then `in1` has to be the
larger array.
Returns
-------
out : array
An N-dimensional array containing a subset of the discrete linear
convolution of `in1` with `in2`.
"""
in1 = asarray(in1)
in2 = asarray(in2)
#if matrix_rank(in1) == matrix_rank(in2) == 0: # scalar inputs
# return in1 * in2
#elif not in1.ndim == in2.ndim:
if not in1.ndim == in2.ndim:
raise ValueError("in1 and in2 should have the same rank")
elif in1.size == 0 or in2.size == 0: # empty arrays
return array([])
s1 = np.array(in1.shape)
s2 = np.array(in2.shape)
complex_result = (np.issubdtype(in1.dtype, np.complex128)
or np.issubdtype(in2.dtype, np.complex128))
fsize = s1
fslice = tuple([slice(0, int(sz)) for sz in fsize])
if not complex_result:
ret = irfftn(rfftn(in1, fsize) * rfftn(in2, fsize),
fsize)[fslice].copy()
ret = ret.real
else:
ret = ifftn(fftn(in1, fsize) * fftn(in2, fsize))[fslice].copy()
# Shift the axes back
shift = np.floor(fsize * 0.5).astype(int)
list_of_axes = tuple(np.arange(0, shift.size))
ret = roll(ret, -shift, axis=list_of_axes)
return ret
def zeroextract2d(N,filename):
a = fromfile(filename)
a = a.reshape(9,N,N)
b = numpy.zeros((9,N/2,N/2),float)
for i in range(9):
ka = fft.rfftn(a[i])
kb = numpy.zeros((N/2,N/4+1),complex)
kb[:N/4,:]=ka[:N/4,:N/4+1]
kb[-N/4:,:]=ka[-N/4:,:N/4+1]
b[i] = fft.irfftn(kb)
b /= 4.
b.tofile(filename.replace(str(N),str(N/2)))
def SpatialCorrelationFunctionA(Field1, Field2):
"""
Designed for Periodic Boundary Condition.
Corr_12(r) = <Phi_1(r)Phi_2(0)>
Corr_12(k) = Phi_1(k)* Phi_2(k)/V
"""
V = float(numpy.array(Field1.shape).prod())
KField1 = fft.rfftn(Field1).conj()
KField2 = fft.rfftn(Field2)
KCorr = KField1 * KField2 / V
Corr = fft.irfftn(KCorr)
return Corr
def fftconvolve(in1, in2):
"""Convolve two N-dimensional arrays using FFT.
This is a modified version of the scipy.signal.fftconvolve.
The new feature is derived from the fftconvolve algorithm used in the IDL package.
Parameters
----------
in1 : array_like
First input.
in2 : array_like
Second input. Should have the same number of dimensions as `in1`;
if sizes of `in1` and `in2` are not equal then `in1` has to be the
larger array.
Returns
-------
out : array
An N-dimensional array containing a subset of the discrete linear
convolution of `in1` with `in2`.
"""
in1 = asarray(in1)
in2 = asarray(in2)
if matrix_rank(in1) == matrix_rank(in2) == 0: # scalar inputs
return in1 * in2
elif not in1.ndim == in2.ndim:
raise ValueError("in1 and in2 should have the same rank")
elif in1.size == 0 or in2.size == 0: # empty arrays
return array([])
s1 = np.array(in1.shape)
s2 = np.array(in2.shape)
complex_result = (np.issubdtype(in1.dtype, np.complex) or
np.issubdtype(in2.dtype, np.complex))
fsize = s1
fslice = tuple([slice(0, int(sz)) for sz in fsize])
if not complex_result:
ret = irfftn(rfftn(in1, fsize) *
rfftn(in2, fsize), fsize)[fslice].copy()
ret = ret.real
else:
ret = ifftn(fftn(in1, fsize) * fftn(in2, fsize))[fslice].copy()
shift = array([int(floor(fsize[0]/2.0)), int(floor(fsize[1]/2.0))])
ret = roll(roll(ret, -shift[0], axis=0), -shift[1], axis=1)
return ret
def comp_ifftn(values, axes_list, is_real=True):
"""Computes the Inverse Fourier Transform
Parameters
----------
values: ndarray
ndarray of the FT
Returns
-------
IFT
"""
axes = []
shape = []
is_onereal = False
is_half = False
axis_names = [axis.name for axis in axes_list]
for axis in axes_list:
if axis.transform == "ifft":
if is_real and axis.name == "time":
axes.append(axis.index)
shape.append(2 * (values.shape[axis.index] - 1))
is_onereal = True
elif is_real and axis.name == "angle" and "time" not in axis_names:
axes.append(axis.index)
shape.append(values.shape[axis.index])
is_half = True
else:
axes = [axis.index] + axes
shape = [values.shape[axis.index]] + shape
size = array(shape).prod()
if is_onereal:
values = values * size / 2
values_shift = ifftshift(values, axes=axes[:-1])
slice_0 = take(values_shift, 0, axis=axes[-1])
slice_0 *= 2
other_values = delete(values_shift, 0, axis=axes[-1])
values = insert(other_values, 0, slice_0, axis=axes[-1])
values_IFT = irfftn(values, axes=axes)
elif is_half:
values = values * size / 2
values_shift = ifftshift(values, axes=axes[:-1])
slice_0 = take(values_shift, 0, axis=axes[-1])
slice_0 *= 2
other_values = delete(values_shift, 0, axis=axes[-1])
values = insert(other_values, 0, slice_0, axis=axes[-1])
values_IFT = ifftn(values, axes=axes)
else:
values_shift = ifftshift(values, axes=axes) * size
values_IFT = ifftn(values_shift, axes=axes)
return values_IFT
def get_covariance_submatrix(IQdata, lags, q):
logging.debug('Calculating Submatrix')
I1 = np.asarray(IQdata[0])
Q1 = np.asarray(IQdata[1])
I2 = np.asarray(IQdata[2])
Q2 = np.asarray(IQdata[3])
lags = int(lags)
start = len(I1) - lags - 1
stop = len(I1) + lags
sub_matrix = np.zeros([4, lags * 2 + 1])
sI1 = np.array(I1.shape)
shape0 = sI1*2 - 1
fshape = [_next_regular(int(d)) for d in shape0] # padding to optimal size for FFTPACK
fslice = tuple([slice(0, int(sz)) for sz in shape0]) # remove padding later
fftI1 = rfftn(I1, fshape)/fshape
fftQ1 = rfftn(Q1, fshape)/fshape
rfftI2 = rfftn(I2[::-1], fshape)/fshape
rfftQ2 = rfftn(Q2[::-1], fshape)/fshape
sub_matrix[0] = irfftn((fftI1 * rfftI2))[fslice].copy()[start:stop] # <II>
sub_matrix[1] = irfftn((fftI1 * rfftQ2))[fslice].copy()[start:stop] # <IQ>
sub_matrix[2] = irfftn((fftQ1 * rfftI2))[fslice].copy()[start:stop] # <QI>
sub_matrix[3] = irfftn((fftQ1 * rfftQ2))[fslice].copy()[start:stop] # <QQ>
q.put(sub_matrix)
def KspaceInitializer(gridShape, fileDictionary, state = None):
"""
Initialize plasticity state by reading from files given by the file
dictionary.
File dictionary must be a dictionary(hash) with component of field as
its keys and filename pair(for real and imaginary) as its values.
State must first be initialized and passed in for non default plasticity
states.
example:
fileDictionary = {('x','z') : \
("InitialConditions/InitFourierCoeffXZ_real256.dat", \
"InitialConditions/InitFourierCoeffXZ_im256.dat"),\
('y','z') : ("InitialConditions/InitFourierCoeffYZ_real256.dat", \
"InitialConditions/InitFourierCoeffYZ_im256.dat"),\
('z','x') : ("InitialConditions/InitFourierCoeffZX_real256.dat", \
"InitialConditions/InitFourierCoeffZX_im256.dat")}
"""
if state is None:
state = PlasticityState.PlasticityState(gridShape)
field = state.GetOrderParameterField()
kGridShape = list(gridShape)
kGridShape[-1] = int(kGridShape[-1]/2)+1
kGridShape = tuple(kGridShape)
totalSize = 1
for sz in kGridShape:
totalSize *= sz
for component in fileDictionary:
rePart = numpy.fromfile(fileDictionary[component][0])
imPart = numpy.fromfile(fileDictionary[component][1])
kSpaceArray = rePart + 1.0j*imPart
"""
Strip down only first half rows as this is the only data that gets
used. Notice that we are actually taking real fourier transform on
last axis, nevertheless we only take half data from the top. i.e.
this may not very intuitive, but is coded this way for compatibility
with Yor's old C++ version. i.e., strip down only half rows, and re-
arrange so that column is halved. (That is, second half of first row
becomes the second row and first half of second row becomes the third.
"""
kSpaceArray = kSpaceArray[:totalSize].reshape(kGridShape)
field[component] = fft.irfftn(kSpaceArray)
return state
def _cpu_search(self):
d = self.data
c = self.cpu_data
time0 = _time()
for n in xrange(c['rotmat'].shape[0]):
# rotate ligand image
rotate_image3d(c['im_lsurf'], c['vlength'],
np.linalg.inv(c['rotmat'][n]), d['im_center'], c['lsurf'])
c['ft_lsurf'] = rfftn(c['lsurf']).conj()
c['clashvol'] = irfftn(c['ft_lsurf'] * c['ft_rcore'], s=c['shape'])
c['intervol'] = irfftn(c['ft_lsurf'] * c['ft_rsurf'], s=c['shape'])
np.logical_and(c['clashvol'] < c['max_clash'],
c['intervol'] > c['min_interaction'],
c['interspace'])
print('Number of complexes to analyze: ', c['interspace'].sum())
c['chi2'].fill(0)
calc_chi2(c['interspace'], c['q'], c['base_Iq'],
c['rind'], c['rxyz'], c['lind'], (np.mat(c['rotmat'][n])*np.mat(c['lxyz']).T).T,
c['origin'], self.voxelspacing,
c['fifj'], c['targetIq'], c['sq'], c['chi2'])
ind = c['chi2'] > c['best_chi2']
c['best_chi2'][ind] = c['chi2'][ind]
c['rot_ind'][ind] = n
if _stdout.isatty():
self._print_progress(n, c['nrot'], time0)
d['best_chi2'] = c['best_chi2']
d['rot_ind'] = c['rot_ind']
def SpatialCorrelationFunction(Field1,Field2):
"""
Designed for Periodic Boundary Condition.
.. math::
C_{12}(r) = <F_1(r) F_2(0)>
C_{12}(k) = F_1(k)* F_2(k)/V
"""
V = float(numpy.array(Field1.shape).prod())
KField1 = fft.rfftn(Field1).conj()
KField2 = fft.rfftn(Field2)
KCorr = KField1*KField2/V
Corr = fft.irfftn(KCorr)
return Corr
def multichannel_overlap_add_fftconvolve(x, h, mode='valid'):
"""Given a signal x compute the convolution with h using the overlap-add algorithm.
This is an fft based convolution algorithm optimized to work on a signal x
and filter, h, where x is much longer than h.
Input:
x: float array with dimensions (N, num_channel)
h: float array with dimensions (filter_len, num_channel)
mode: only accepts valid - same profile scipy.convolve
Returns:
float array of length N-filter_len+1 (for mode = valid)
"""
assert mode == 'valid'
# pad x so that the boundaries are dealt with correctly
x_len = x.shape[0]
num_channels = h.shape[1]
h_len = h.shape[0]
assert x.shape[1] == num_channels
assert x_len >= h_len, \
"The signal needs to be at least as long as the filter"
#x = np.vstack((np.zeros((h_len, num_channels)),
# x,
# np.zeros((h_len, num_channels))))
# make sure that the desired block size is long enough to capture the motif
block_size = max(2**OVERLAP_ADD_BLOCK_POWER, h_len)
N = int(2**math.ceil(np.log2(block_size+h_len-1)))
step_size = N-h_len+1
H = rfftn(h,(N,num_channels))
n_blocks = int(math.ceil(float(len(x))/step_size))
y = np.zeros((n_blocks+1)*step_size)
for block_index in xrange(n_blocks):
start = block_index*step_size
yt = irfftn( rfftn(x[start:start+step_size,:],(N, num_channels))*H,
(N, num_channels) )
y[start:start+N] += yt[:,num_channels-1]
#y = y[h_len:2*h_len+x_len-1]
if mode == 'full':
return y
elif mode == 'valid':
return y[h_len-1:x_len]
elif mode == 'same':
raise NotImplementedError, "'same' mode is not implemented"
def multichannel_overlap_add_fftconvolve(x, h, mode='valid'):
"""Given a signal x compute the convolution with h using the overlap-add algorithm.
This is an fft based convolution algorithm optimized to work on a signal x
and filter, h, where x is much longer than h.
Input:
x: float array with dimensions (N, num_channel)
h: float array with dimensions (filter_len, num_channel)
mode: only accepts valid - same profile scipy.convolve
Returns:
float array of length N-filter_len+1 (for mode = valid)
"""
assert mode == 'valid'
# pad x so that the boundaries are dealt with correctly
x_len = x.shape[0]
num_channels = h.shape[1]
h_len = h.shape[0]
assert x.shape[1] == num_channels
assert x_len >= h_len, \
"The signal needs to be at least as long as the filter"
#x = np.vstack((np.zeros((h_len, num_channels)),
# x,
# np.zeros((h_len, num_channels))))
# make sure that the desired block size is long enough to capture the motif
block_size = max(2**OVERLAP_ADD_BLOCK_POWER, h_len)
N = int(2**math.ceil(np.log2(block_size+h_len-1)))
step_size = N-h_len+1
H = rfftn(h,(N,num_channels))
n_blocks = int(math.ceil(float(len(x))/step_size))
y = np.zeros((n_blocks+1)*step_size)
for block_index in xrange(n_blocks):
start = block_index*step_size
yt = irfftn( rfftn(x[start:start+step_size,:],(N, num_channels))*H,
(N, num_channels) )
y[start:start+N] += yt[:,num_channels-1]
#y = y[h_len:2*h_len+x_len-1]
if mode == 'full':
return y
elif mode == 'valid':
return y[h_len-1:x_len]
elif mode == 'same':
raise NotImplementedError, "'same' mode is not implemented"
def cross_correlation(seqs):
# deal with the shape, and upcast to the next reasonable shape
shape = np.array(seqs.shape[1:]) + np.array(seqs.shape[1:]) - 1
fshape = [next_good_fshape(x) for x in shape]
fslice = tuple([slice(0, int(sz)) for sz in shape])
flipped_seqs_fft = np.zeros([seqs.shape[0],] + fshape[:-1] + [fshape[-1]//2+1,], dtype='complex')
for i in xrange(seqs.shape[0]):
rev_slice = tuple([i,] + [slice(None, None, -1) for sz in shape])
flipped_seqs_fft[i] = rfftn(seqs[rev_slice], fshape)
rv = np.zeros((seqs.shape[0], seqs.shape[0]), dtype='float32')
for i in xrange(seqs.shape[0]):
fft_seq = rfftn(seqs[i], fshape)
for j in xrange(i+1, seqs.shape[0]):
rv[i,j] = irfftn(fft_seq*flipped_seqs_fft[j], fshape)[fslice].max()
#print rv[i,j], correlate(seqs[i], seqs[j]).max()
return rv
def get_g2(P1, P2, lags=20):
''' Returns the Top part of the G2 equation (<P1P2> - <P1><P2>)'''
lags = int(lags)
P1 = np.asarray(P1)
P2 = np.asarray(P2)
# G2 = np.zeros([lags*2-1])
start = len(P1*2-1)-lags
stop = len(P1*2-1)-1+lags
# assume I1 Q1 have the same shape
sP1 = np.array(P1.shape)
complex_result = np.issubdtype(P1.dtype, np.complex)
shape = sP1 - 1
HPfilt = (int(sP1/(lags*4))) # smallest features visible is lamda/4
# Speed up FFT by padding to optimal size for FFTPACK
fshape = [_next_regular(int(d)) for d in shape]
fslice = tuple([slice(0, int(sz)) for sz in shape])
# Pre-1.9 NumPy FFT routines are not threadsafe. For older NumPys, make
# sure we only call rfftn/irfftn from one thread at a time.
if not complex_result and _rfft_lock.acquire(False):
try:
fftP1 = rfftn(P1, fshape)
rfftP2 = rfftn(P2[::-1], fshape)
fftP1 = np.concatenate((np.zeros(HPfilt), fftP1[HPfilt:]))
rfftP2 = np.concatenate((np.zeros(HPfilt), rfftP2[HPfilt:]))
G2 = irfftn((fftP1*rfftP2))[fslice].copy()[start:stop]/len(fftP1)
return
finally:
_rfft_lock.release()
else:
# If we're here, it's either because we need a complex result, or we
# failed to acquire _rfft_lock (meaning rfftn isn't threadsafe and
# is already in use by another thread). In either case, use the
# (threadsafe but slower) SciPy complex-FFT routines instead.
# ret = ifftn(fftn(in1, fshape) * fftn(in2, fshape))[fslice].copy()
print 'Abort, reason:complex input or Multithreaded FFT not available'
if not complex_result:
pass # ret = ret.real
P12var = np.var(P1)*np.var(P2)
return G2-P12var
def SpatialCorrelationFunctionA(Field1,Field2):
"""
Corr_12(r) = <Phi_1(r)Phi_2(0)>
Corr_12(k) = Phi_1(k)* Phi_2(k)/V
"""
dim = len(Field1.shape)
if dim == 1:
V=float(Field1.shape[0])
elif dim == 2:
V=float(Field1.shape[0]*Field1.shape[1])
elif dim == 3:
V=float(Field1.shape[0]*Field1.shape[1]*Field1.shape[2])
KField1 = fft.rfftn(Field1).conj()
KField2 = fft.rfftn(Field2)
KCorr = KField1*KField2/V
Corr = fft.irfftn(KCorr)
return Corr
def pivCrossCorrelation2D(voxA,voxB,width,offset1,offset2):
vox1 = np.array(voxA[offset1[0]:offset1[0]+width,\
offset1[1]:offset1[1]+width ],dtype="float");
#
vox2 = np.array(voxB[offset2[0]:offset2[0]+width,\
offset2[1]:offset2[1]+width ],dtype="float");
#
#
siz = np.array(vox1.shape)*2;
#
#
# remove median
vox1 -= np.mean( vox1 );
vox2 -= np.mean( vox2 );
#
# cross correlation - padded with zeros
R=(1.0/(width*width))*np.real(fftshift(irfftn( np.conj(rfftn(vox1,siz)) * rfftn(vox2,siz) )));
return R
def extended_source_image_(self, ideal_image):
# Convolve
assert np.alltrue(ideal_image.shape == self._expected_shape
), "Shape of image to be convolved is not correct."
ret = irfftn(
rfftn(ideal_image, self._fshape) * self._psf_fft,
self._fshape)[self._fslice].copy()
conv = _centered(ret, self._expected_shape)
#
# fig, sub = plt.subplots(1,1)
#
# #sub[0].imshow(ideal_image, interpolation='none', cmap='gist_heat')
# sub.imshow(conv, interpolation='none', cmap='gist_heat')
#
# fig.savefig("convolution.png")
return conv
def fourier_lowpass(x, r):
'''
Fourier lowpass of a 3-D volume
Parameters
==========
x : numpy.ndarray
x.ndim == 3
r : double
Cut-off frequency for Fourier lowpass.
The unit of r is the number of voxels.
The resolution is box_size * voxel_size / r.
'''
fx = rfftn(fftshift(x), norm='ortho')
for (i, j, k) in np.ndindex(fx.shape):
ii = i if i < fx.shape[0] // 2 else i - fx.shape[0]
jj = j if j < fx.shape[1] // 2 else j - fx.shape[1]
kk = k
rho = sqrt(ii**2 + jj**2 + kk**2)
if rho > r:
fx[i, j, k] = 0
return ifftshift(irfftn(fx, norm='ortho'))
def get_covariance_submatrix_full(IQdata, lags):
I1 = np.asarray(IQdata[0])
# Q1 = np.asarray(IQdata[1])
# I2 = np.asarray(IQdata[2])
Q2 = np.asarray(IQdata[3])
lags = int(lags)
start = len(I1) - lags - 1
stop = len(I1) + lags
sub_matrix = np.zeros([16, lags * 2 + 1])
sI1 = np.array(I1.shape)
shap0 = sI1*2 - 1
fshape = [_next_regular(int(d)) for d in shap0] # padding to optimal size for FFTPACK
fslice = tuple([slice(0, int(sz)) for sz in shap0]) # remove padding later
fftIQ = 4*[None]
rfftIQ = 4*[None]
for i in range(4):
fftIQ[i] = rfftn(IQdata[i], fshape)
rfftIQ[i] = rfftn(IQdata[i][::-1], fshape)
for j in range(4):
for i in range(4):
idx = i + j*4
sub_matrix[idx] = (irfftn(fftIQ[i]*rfftIQ[j]))[fslice].copy()[start:stop]/len(fftIQ[i])
return sub_matrix
def SmecticInitializer(gridShape, sigma=0.2, seed=None):
if seed is None:
seed = 0
random.seed(seed)
state = SmecticState.SmecticState(gridShape)
field = state.GetOrderParameterField()
Ksq = FourierSpaceTools.FourierSpaceTools(gridShape).kSq.numpy_array()
for component in field.components:
temp = random.normal(scale=gridShape[0],size=gridShape)
ktemp = fft.rfftn(temp)*(sqrt(pi)*sigma)**len(gridShape)*exp(-Ksq*sigma**2/4.)
field[component] = numpy.real(fft.irfftn(ktemp))
## To make seed consistent across grid sizes and convergence comparison
gridShape = copy.copy(oldgrid)
if gridShape[0] != 128:
state = ResizeState(state,gridShape[0],Dim=len(gridShape))
state = ReformatState(state)
state.ktools = FourierSpaceTools.FourierSpaceTools(gridShape)
return state
def fftconvolve_fast(data, kernel, **kwargs):
"""FFT convolution, a faster version than scipy.
In this case the kernel ifftshifted before FFT but the data is not.
This can be done because the effect of fourier convolution is to
"wrap" around the data edges so whether we ifftshift before FFT
and then fftshift after it makes no difference so we can skip the
step entirely.
"""
# TODO: add error checking like in the above and add functionality
# for complex inputs. Also could add options for different types of
# padding.
dshape = np.array(data.shape)
kshape = np.array(kernel.shape)
# find maximum dimensions
maxshape = np.max((dshape, kshape), 0)
# calculate a nice shape
fshape = [next_fast_len(int(d)) for d in maxshape]
# pad out with reflection
pad_data = fft_pad(data, fshape, "reflect")
# calculate padding
padding = tuple(
_calc_pad(o, n) for o, n in zip(data.shape, pad_data.shape))
# so that we can calculate the cropping, maybe this should be integrated
# into `fft_pad` ...
fslice = tuple(
slice(s, -e) if e != 0 else slice(s, None) for s, e in padding)
if kernel.shape != pad_data.shape:
# its been assumed that the background of the kernel has already been
# removed and that the kernel has already been centered
kernel = fft_pad(kernel, pad_data.shape, mode="constant")
k_kernel = rfftn(ifftshift(kernel), pad_data.shape, **kwargs)
k_data = rfftn(pad_data, pad_data.shape, **kwargs)
convolve_data = irfftn(k_kernel * k_data, pad_data.shape, **kwargs)
# return data with same shape as original data
return convolve_data[fslice]
def smooth(self, in_data, clean=False, is_fft=False):
"""Apply smoothing to `in_data`
Parameters
----------
in_data: array_like
The array to be smoothed. should be same shape as the
shape provided during instantiation of this object
clean: bool, optional
Should we call ``nan_to_num`` on the data before smoothing?
is_fft: bool, optional
Has the data already been fft'd?
Returns
-------
_out: array of same shape as input nin_data
smoothed in_data
Notes
-----
XXX: is the manual garbage collection --via calls to gc.collect()--
actually necessary ? Is it dangerous ?
"""
# nothing to do ?
if not np.sum(self._fwhm) > 0:
return in_data
# get dimensionality of input data
in_data = np.array(in_data)
ndim = in_data.ndim
if ndim == 4:
_out = np.ndarray(in_data.shape)
n_scans = in_data.shape[-1]
elif ndim == 3:
n_scans = 1
else:
raise ValueError('expecting either 3 or 4-d image')
slices = [
slice(0, self._bshape[i], 1) for i in range(len(self._shape))
]
for _scan in range(n_scans):
if ndim == 4:
data = in_data[..., _scan]
elif ndim == 3:
data = in_data[:]
if clean:
data = np.nan_to_num(data)
if not is_fft:
data = self._presmooth(data, slices)
data *= self.fkernel
data = npfft.irfftn(data) / self._norm
gc.collect()
_dslice = [slice(0, self._bshape[i], 1) for i in range(3)]
if self._scale != 1:
data = self._scale * data[_dslice]
if self._location != 0.0:
data += self._location
gc.collect()
# Write out data
if ndim == 4:
_out[..., _scan] = data
else:
_out = data
# collect output
_out = _out[[
slice(self._kernel.shape[i] // 2,
self._bshape[i] + self._kernel.shape[i] // 2)
for i in range(len(self._bshape))
]]
# return output
return _out
if __name__ == "__main__":
if torch.cuda.is_available():
nfft3 = lambda x: nfft.fftn(x, axes=(1, 2, 3))
nifft3 = lambda x: nfft.ifftn(x, axes=(1, 2, 3))
cfs = [cfft.fft, cfft.fft2, cfft.fft3]
nfs = [nfft.fft, nfft.fft2, nfft3]
cifs = [cfft.ifft, cfft.ifft2, cfft.ifft3]
nifs = [nfft.ifft, nfft.ifft2, nifft3]
for args in zip(cfs, nfs, cifs, nifs):
test_c2c(*args)
nrfft3 = lambda x: nfft.rfftn(x, axes=(1, 2, 3))
nirfft3 = lambda x: nfft.irfftn(x, axes=(1, 2, 3))
cfs = [cfft.rfft, cfft.rfft2, cfft.rfft3]
nfs = [nfft.rfft, nfft.rfft2, nrfft3]
cifs = [cfft.irfft, cfft.irfft2, cfft.irfft3]
nifs = [nfft.irfft, nfft.irfft2, nirfft3]
for args in zip(cfs, nfs, cifs, nifs):
test_r2c(*args)
test_expand()
test_fft_gradcheck()
test_ifft_gradcheck()
test_fft2d_gradcheck()
test_ifft2d_gradcheck()
test_fft3d_gradcheck()
def irfftn(self, shape=None):
return NumpyArray(fft.irfftn(self, shape))
def calculate_6d_integral(self, n_g, q0_g, a2_g=None, e_LDAc_g=None, v_LDAc_g=None, v_g=None, deda2_g=None):
self.timer.start("VdW-DF integral")
self.timer.start("splines")
if self.C_aip is None:
self.construct_cubic_splines()
self.construct_fourier_transformed_kernels()
self.timer.stop("splines")
gd = self.gd
N = self.Nalpha
world = self.world
vdwcomm = self.vdwcomm
if self.alphas:
self.timer.start("hmm1")
i_g = (np.log(q0_g / self.q_a[1] * (self.lambd - 1) + 1) / log(self.lambd)).astype(int)
dq0_g = q0_g - self.q_a[i_g]
self.timer.stop("hmm1")
else:
i_g = None
dq0_g = None
if self.verbose:
print "VDW: fft:",
theta_ak = {}
p_ag = {}
for a in self.alphas:
self.timer.start("hmm2")
C_pg = self.C_aip[a, i_g].transpose((3, 0, 1, 2))
pa_g = C_pg[0] + dq0_g * (C_pg[1] + dq0_g * (C_pg[2] + dq0_g * C_pg[3]))
self.timer.stop("hmm2")
del C_pg
self.timer.start("FFT")
theta_ak[a] = rfftn(n_g * pa_g, self.shape).copy()
if extra_parameters.get("vdw0"):
theta_ak[a][0, 0, 0] = 0.0
self.timer.stop()
if not self.energy_only:
p_ag[a] = pa_g
del pa_g
if self.verbose:
print a,
sys.stdout.flush()
if self.energy_only:
del i_g
del dq0_g
if self.verbose:
print
print "VDW: convolution:",
F_ak = {}
dj_k = self.dj_k
energy = 0.0
for a in range(N):
if vdwcomm is not None:
vdw_ranka = a * vdwcomm.size // N
F_k = np.zeros((self.shape[0], self.shape[1], self.shape[2] // 2 + 1), complex)
self.timer.start("Convolution")
for b in self.alphas:
_gpaw.vdw2(self.phi_aajp[a, b], self.j_k, dj_k, theta_ak[b], F_k)
self.timer.stop()
if vdwcomm is not None:
self.timer.start("gather")
for F in F_k:
vdwcomm.sum(F, vdw_ranka)
# vdwcomm.sum(F_k, vdw_ranka)
self.timer.stop("gather")
if vdwcomm is not None and vdwcomm.rank == vdw_ranka:
if not self.energy_only:
F_ak[a] = F_k
energy += np.vdot(theta_ak[a][:, :, 0], F_k[:, :, 0]).real
energy += np.vdot(theta_ak[a][:, :, -1], F_k[:, :, -1]).real
energy += 2 * np.vdot(theta_ak[a][:, :, 1:-1], F_k[:, :, 1:-1]).real
if self.verbose:
print a,
sys.stdout.flush()
del theta_ak
if self.verbose:
print
if not self.energy_only:
F_ag = {}
for a in self.alphas:
n1, n2, n3 = gd.get_size_of_global_array()
self.timer.start("iFFT")
F_ag[a] = irfftn(F_ak[a]).real[:n1, :n2, :n3].copy()
self.timer.stop()
del F_ak
self.timer.start("potential")
self.calculate_potential(n_g, a2_g, i_g, dq0_g, p_ag, F_ag, e_LDAc_g, v_LDAc_g, v_g, deda2_g)
self.timer.stop()
self.timer.stop()
return 0.5 * world.sum(energy) * gd.dv / self.shape.prod()
def smooth(self, inimage, clean=False, is_fft=False):
""" Apply smoothing to `inimage`
Parameters
----------
inimage : ``Image``
The image to be smoothed. Should be 3D.
clean : bool, optional
Should we call ``nan_to_num`` on the data before smoothing?
is_fft : bool, optional
Has the data already been fft'd?
Returns
-------
s_image : `Image`
New image, with smoothing applied
"""
if inimage.ndim == 4:
# we need to generalize which axis to iterate over. By
# default it should probably be the last.
raise NotImplementedError('Smoothing volumes in a 4D series '
'is broken, pending a rethink')
_out = np.zeros(inimage.shape)
# iterate over the first (0) axis - this is confusing - see
# above
nslice = inimage.shape[0]
elif inimage.ndim == 3:
nslice = 1
else:
raise NotImplementedError('expecting either 3 or 4-d image')
in_data = inimage.get_data()
for _slice in range(nslice):
if in_data.ndim == 4:
data = in_data[_slice]
elif in_data.ndim == 3:
data = in_data[:]
if clean:
data = np.nan_to_num(data)
if not is_fft:
data = self._presmooth(data)
data *= self.fkernel
data = fft.irfftn(data) / self.norms[self.normalization]
gc.collect()
_dslice = [slice(0, self.bshape[i], 1) for i in range(3)]
if self.scale != 1:
data = self.scale * data[_dslice]
if self.location != 0.0:
data += self.location
gc.collect()
# Write out data
if in_data.ndim == 4:
_out[_slice] = data
else:
_out = data
_slice += 1
gc.collect()
_out = _out[[slice(self._kernel.shape[i]/2, self.bshape[i] +
self._kernel.shape[i]/2) for i in range(len(self.bshape))]]
if inimage.ndim == 3:
return Image(_out, coordmap=self.coordmap)
else:
# This does not work as written. See above
concat_affine = AffineTransform.identity('concat')
return Image(_out, coordmap=product(self.coordmap, concat_affine))
def _irfftn(a, s=None, axes=None):
return npfft.irfftn(a, s, axes).astype(real_dtype(a.dtype))
def irfft(a, normalize=True, nthreads=ncpu):
if normalize:
return fftw.irfftn(a)
else:
return fftw.irfft(a)
def get_real_image(self):
if self.image is None:
self.image = irfftn(self.ft, self.imageshape)
return self.image
def __init__(self, npow=-4., ngrid=256, xmax=1., dx=0.01, seed=27021987):
start = time()
print("Creating 3-D velocity grid with power spectrum P_k~k**{}".\
format(npow))
if ngrid % 2 != 0:
print("Grid points must be an even number. Exiting.")
exit()
nc = int(ngrid / 2) + 1
kmax = 2 * pi / dx
kmin = 2 * pi / xmax
kx = fft.fftfreq(ngrid, d=1 / (2 * kmax))
ky = kx
kz = fft.rfftfreq(ngrid, d=1 / (2 * kmax))
# we produce a 3-D grid of the Fourier coordinates
kxx, kyy, kzz = meshgrid(kx, ky, kz, indexing='ij', sparse=True)
kk = kxx * kxx + kyy * kyy + kzz * kzz + kmin**2
random.seed(seed)
# we sample the components of a vector potential, as we want
# an incompresible velocity field
xi1 = random.random(size=kk.shape)
xi2 = random.random(size=kk.shape)
c = kk**((npow - 2.) / 4.) * sqrt(-log(1 - xi1))
phi = 2 * pi * xi2
akx = c * exp(1j * phi)
xi1 = random.random(size=kk.shape)
xi2 = random.random(size=kk.shape)
c = kk**((npow - 2.) / 4.) * sqrt(-log(1 - xi1))
phi = 2 * pi * xi2
aky = c * exp(1j * phi)
xi1 = random.random(size=kk.shape)
xi2 = random.random(size=kk.shape)
c = kk**((npow - 2.) / 4.) * sqrt(-log(1 - xi1))
phi = 2 * pi * xi2
akz = c * exp(1j * phi)
new_shape = akx.shape + (3, )
kv = zeros(new_shape, dtype=akx.dtype)
kv[:, :, :, 0] = 1j * kxx
kv[:, :, :, 1] = 1j * kyy
kv[:, :, :, 2] = 1j * kzz
ak = zeros(new_shape, dtype=akx.dtype)
ak[:, :, :, 0] = akx
ak[:, :, :, 1] = aky
ak[:, :, :, 2] = akz
# the velocity vector in Fourier space is obtained by
# taking the curl of A, which is
vk = cross(kv, ak)
self.ngrid = ngrid
self.vx = fft.irfftn(vk[:, :, :, 0])
self.vy = fft.irfftn(vk[:, :, :, 1])
self.vz = fft.irfftn(vk[:, :, :, 2])
print("\nInverse Fourier Transform took {:g}s.".format(time() - start))
def test_r2c_outofplace(self):
"""
Test out-of-place R2C transforms
"""
n = 32
for dims in range(1, 5):
if dims >= 3:
ndim_max = min(dims + 1, 2)
else:
ndim_max = min(dims + 1, 3)
for ndim in range(1, ndim_max):
for dtype in [np.float32, np.float64]:
for norm in [0, 1, "ortho"]:
with self.subTest(dims=dims,
ndim=ndim,
dtype=dtype,
norm=norm):
if dtype == np.float32:
rtol = 1e-6
else:
rtol = 1e-12
if dtype == np.float32:
dtype_c = np.complex64
elif dtype == np.float64:
dtype_c = np.complex128
sh = [n] * dims
sh = tuple(sh)
shc = [n] * dims
shc[-1] = n // 2 + 1
shc = tuple(shc)
d = np.random.uniform(0, 1, sh).astype(dtype)
# A pure random array may not be a very good test (too random),
# so add a Gaussian
xx = [
np.fft.fftshift(np.fft.fftfreq(nn))
for nn in sh
]
v = np.zeros_like(d)
for x in np.meshgrid(*xx, indexing='ij'):
v += x**2
d += 10 * np.exp(-v * 2)
n0 = (abs(d)**2).sum()
d_gpu = cua.to_gpu(d)
d1_gpu = cua.empty(shc, dtype=dtype_c)
app = VkFFTApp(d.shape,
d.dtype,
ndim=ndim,
norm=norm,
r2c=True,
inplace=False)
# base FFT scale
s = np.sqrt(np.prod(d.shape[-ndim:]))
d = rfftn(d, axes=list(range(dims))[-ndim:]) / s
d1_gpu = app.fft(d_gpu, d1_gpu)
d1_gpu *= dtype_c(app.get_fft_scale())
self.assertTrue(d1_gpu.shape == tuple(shc))
self.assertTrue(d1_gpu.dtype == dtype_c)
self.assertTrue(
np.allclose(d,
d1_gpu.get(),
rtol=rtol,
atol=abs(d).max() * rtol))
d = irfftn(d, axes=list(range(dims))[-ndim:]) * s
d_gpu = app.ifft(d1_gpu, d_gpu)
d_gpu *= dtype(app.get_ifft_scale())
self.assertTrue(d_gpu.shape == tuple(sh))
self.assertTrue(
np.allclose(d,
d_gpu.get(),
rtol=rtol,
atol=abs(d).max() * rtol))
n1 = (abs(d_gpu.get())**2).sum()
self.assertTrue(np.isclose(n0, n1, rtol=rtol))
def smooth(self, inimage, clean=False, is_fft=False):
""" Apply smoothing to `inimage`
Parameters
----------
inimage : ``Image``
The image to be smoothed. Should be 3D.
clean : bool, optional
Should we call ``nan_to_num`` on the data before smoothing?
is_fft : bool, optional
Has the data already been fft'd?
Returns
-------
s_image : `Image`
New image, with smoothing applied
"""
if inimage.ndim == 4:
# we need to generalize which axis to iterate over. By
# default it should probably be the last.
raise NotImplementedError('Smoothing volumes in a 4D series '
'is broken, pending a rethink')
_out = np.zeros(inimage.shape)
# iterate over the first (0) axis - this is confusing - see
# above
nslice = inimage.shape[0]
elif inimage.ndim == 3:
nslice = 1
else:
raise NotImplementedError('expecting either 3 or 4-d image')
in_data = inimage.get_data()
for _slice in range(nslice):
if in_data.ndim == 4:
data = in_data[_slice]
elif in_data.ndim == 3:
data = in_data[:]
if clean:
data = np.nan_to_num(data)
if not is_fft:
data = self._presmooth(data)
data *= self.fkernel
data = fft.irfftn(data) / self.norms[self.normalization]
gc.collect()
_dslice = [slice(0, self.bshape[i], 1) for i in range(3)]
if self.scale != 1:
data = self.scale * data[_dslice]
if self.location != 0.0:
data += self.location
gc.collect()
# Write out data
if in_data.ndim == 4:
_out[_slice] = data
else:
_out = data
_slice += 1
gc.collect()
_out = _out[[
slice(self._kernel.shape[i] / 2,
self.bshape[i] + self._kernel.shape[i] / 2)
for i in range(len(self.bshape))
]]
if inimage.ndim == 3:
return Image(_out, coordmap=self.coordmap)
else:
# This does not work as written. See above
concat_affine = AffineTransform.identity('concat')
return Image(_out, coordmap=product(self.coordmap, concat_affine))
def ifft(y, ax, ncpu, lastsize):
return irfftn(y, axes=ax)
def fftconvolve(in1, in2, mode="full"):
"""Convolve two N-dimensional arrays using FFT, implemented using the pyfftw module ('Fastest Fourier Transform in the West').
Convolve `in1` and `in2` using the fast Fourier transform method, with
the output size determined by the `mode` argument.
This is generally much faster than `convolve` for large arrays (n > ~500),
but can be slower when only a few output values are needed, and can only
output float arrays (int or object array inputs will be cast to float).
Parameters
----------
in1 : array_like
First input.
in2 : array_like
Second input. Should have the same number of dimensions as `in1`;
if sizes of `in1` and `in2` are not equal then `in1` has to be the
larger array.
mode : str {'full', 'valid', 'same'}, optional
A string indicating the size of the output:
``full``
The output is the full discrete linear convolution
of the inputs. (Default)
``valid``
The output consists only of those elements that do not
rely on the zero-padding.
``same``
The output is the same size as `in1`, centered
with respect to the 'full' output.
Returns
-------
out : array
An N-dimensional array containing a subset of the discrete linear
convolution of `in1` with `in2`.
Examples
--------
Autocorrelation of white noise is an impulse. (This is at least 100 times
as fast as `convolve`.)
>>> from scipy import signal
>>> sig = np.random.randn(1000)
>>> autocorr = signal.fftconvolve(sig, sig[::-1], mode='full')
>>> import matplotlib.pyplot as plt
>>> fig, (ax_orig, ax_mag) = plt.subplots(2, 1)
>>> ax_orig.plot(sig)
>>> ax_orig.set_title('White noise')
>>> ax_mag.plot(np.arange(-len(sig)+1,len(sig)), autocorr)
>>> ax_mag.set_title('Autocorrelation')
>>> fig.show()
Gaussian blur implemented using FFT convolution. Notice the dark borders
around the image, due to the zero-padding beyond its boundaries.
The `convolve2d` function allows for other types of image boundaries,
but is far slower.
>>> from scipy import misc
>>> lena = misc.lena()
>>> kernel = np.outer(signal.gaussian(70, 8), signal.gaussian(70, 8))
>>> blurred = signal.fftconvolve(lena, kernel, mode='same')
>>> fig, (ax_orig, ax_kernel, ax_blurred) = plt.subplots(1, 3)
>>> ax_orig.imshow(lena, cmap='gray')
>>> ax_orig.set_title('Original')
>>> ax_orig.set_axis_off()
>>> ax_kernel.imshow(kernel, cmap='gray')
>>> ax_kernel.set_title('Gaussian kernel')
>>> ax_kernel.set_axis_off()
>>> ax_blurred.imshow(blurred, cmap='gray')
>>> ax_blurred.set_title('Blurred')
>>> ax_blurred.set_axis_off()
>>> fig.show()
"""
# if NTHREADS==0:
# print("WARNING: in fftwconvolve(): NTHREADS = 0, using numpy FFT routines instead...")
in1 = asarray(in1)
in2 = asarray(in2)
if in1.ndim == in2.ndim == 0: # scalar inputs
return in1 * in2
elif not in1.ndim == in2.ndim:
raise ValueError("in1 and in2 should have the same dimensionality")
elif in1.size == 0 or in2.size == 0: # empty arrays
return array([])
s1 = array(in1.shape)
s2 = array(in2.shape)
complex_result = (np.issubdtype(in1.dtype, np.complex) or
np.issubdtype(in2.dtype, np.complex))
shape = s1 + s2 - 1
if mode == "valid":
_check_valid_mode_shapes(s1, s2)
# Speed up FFT by padding to optimal size for FFTPACK
fshape = [_next_regular(int(d)) for d in shape]
fslice = tuple([slice(0, int(sz)) for sz in shape])
# Pre-1.9 NumPy FFT routines are not threadsafe. For older NumPys, make
# sure we only call rfftn/irfftn from one thread at a time.
if not complex_result and (_rfft_mt_safe or _rfft_lock.acquire(False)):
try:
if NTHREADS==0:
ret = irfftn(rfftn(in1, fshape) *
rfftn(in2, fshape), fshape)[fslice].copy()
else:
ret = pyfftw.interfaces.numpy_fft.irfftn(\
pyfftw.interfaces.numpy_fft.rfftn(in1, s=fshape, threads=NTHREADS) * \
pyfftw.interfaces.numpy_fft.rfftn(in2, s=fshape, threads=NTHREADS), \
s=fshape)[fslice].copy()
finally:
if not _rfft_mt_safe:
_rfft_lock.release()
else:
# If we're here, it's either because we need a complex result, or we
# failed to acquire _rfft_lock (meaning rfftn isn't threadsafe and
# is already in use by another thread). In either case, use the
# (threadsafe but slower) SciPy complex-FFT routines instead.
if NTHREADS==0:
ret = ifftn(fftn(in1, fshape) * fftn(in2, fshape))[fslice].copy()
else:
ret = pyfftw.interfaces.numpy_fft.ifftn(\
pyfftw.interfaces.numpy_fft.fftn(in1, fshape) * \
pyfftw.interfaces.numpy_fft.fftn(in2, fshape)\
)[fslice].copy()
if not complex_result:
ret = ret.real
if mode == "full":
return ret
elif mode == "same":
return _centered(ret, s1)
elif mode == "valid":
return _centered(ret, s1 - s2 + 1)
else:
raise ValueError("Acceptable mode flags are 'valid',"
" 'same', or 'full'.")
def invert_jacdict(jacdict, unknowns, targets, tau, test_invertible=False):
"""Given a nested dict of ATI Jacobians that maps unknowns -> targets, e.g. an asymptotic
H_U matrix, get the inverse H_U^(-1) as a nested dict.
This is implemented by inverting the FFT-based multiplication that was implemented above
for ATI, making use of the linearity of the FFT:
- We take the FFT of each ATI Jacobian, padded out to 4*tau-3 as above
(This is done by first packing all Jacobians into a single array A)
- Then, we take the FFT of the identity, centered aroun d2*tau-1 since
we intend it to be the result of a product
- We solve frequency-by-frequency, i.e. for each of 4*tau-3 omegas we solve a k*k
linear system to get A_rfft[omega,...]^(-1)*id_rfft[omega,...]
- We take the inverse FFT of the results, then take only the first 2*tau-1 elements
to get (approximate) inverse Jacobians with times -(tau-1),...,(tau-1), same as
original Jacobians
- We unpack these to get a nested dict of ATI Jacobians that inverts original 'jacdict'
Parameters
----------
jacdict : dict of dict, ATI (or convertible to ATI) Jacobians where jacdict[t][u] gives
asymptotic mapping from unknowns u to targets t in H_U
unknowns : list, names of unknowns in H_U
targets : list, names of targets in H_U
tau : int, convert all ATI Jacobians to size tau and provide inverse in size tau
test_invertible : [optional] bool, use winding number criterion to test whether we should
really be inverting this system (i.e. whether determinate solution)
Returns
-------
inv_jacdict : dict of dict, ATI Jacobians where inv_jacdict[u][t] gives asymptotic mapping
from targets t to unknowns u in H_U^(-1)
"""
k = len(unknowns)
assert k == len(targets)
# stack the k^2 Jacobians relating unknowns to targets into an A matrix
A = jac.pack_asymptotic_jacobians(jacdict, unknowns, targets, tau)
if test_invertible:
# use winding number criterion to test invertibility
if determinacy.winding_criterion(A, N=4096) != 0:
raise ValueError('Trying to invert asymptotic time invariant system of Jacobians' +
' but winding number test says that it is not uniquely invertible!')
# take FFT of first dimension (time) of A (i.e. take FFT separtely of all k^2 Jacobians)
A_rfft = rfftn(A, s=(4*tau-3,), axes=(0,))
# take FFT of identity operator (for efficiency, reuse smaller calc)
id_vec_rfft = rfft(np.arange(4*tau-3)==(2*tau-2))
id_rfft = np.zeros((2*tau-1, k, k), dtype=np.complex128)
for i in range(k):
id_rfft[:, i, i] = id_vec_rfft
# now solve the linear system to invert A frequency-by-frequency
# (since frequency is leading dimension, np.linalg.solve automatically does this)
A_rfft_inv = np.linalg.solve(A_rfft, id_rfft)
# take inverse FFT of this to get full A
# then take first 2*tau-1 entries to get approximate A from -(tau-1),...,0,...,(tau-1)
A_inv = irfftn(A_rfft_inv, s=(4*tau-3,), axes=(0,))[:2*tau-1, :, :]
# unstack this
return jac.unpack_asymptotic_jacobians(A_inv, targets, unknowns, tau)
def sgimgcoeffs(img, *args, **kwargs):
'''
Given a 3-D image img with shape (nx, ny, nz), use Savitzky-Golay
stencils from savgol(*args, **kwargs) to compute compute the filtered
double-precision image coeffs with shape (nx, ny, nz, ns) such that
coeffs[:,:,:,i] holds the convolution of img with the i-th stencil.
If the image is of single precision, the filter correlation will be done
in single-precision; otherwise, double precision will be used.
The pyfftw module will be used, if available, to accelerate FFT
correlations. Otherwise, the stock Numpy FFT will be used.
'''
# Create the stencils first
stencils = savgol(*args, **kwargs)
if not stencils: raise ValueError('Savitzky-Golay stencil list is empty')
# Make sure the array is in double precision
img = np.asarray(img)
if img.ndim != 3: raise ValueError('Image img must be three-dimensional')
# If possible, find the next-larger efficient size
try: from scipy.fftpack.helper import next_fast_len
except ImportError: next_fast_len = lambda x: x
# Half-sizes of kernels along each axis
hsizes = tuple(bsz // 2 for bsz in stencils[0].shape)
# Padded shape for FFT convolution and the R2C FFT output
pshape = tuple(next_fast_len(isz + 2 * bsz)
for isz, bsz in zip(img.shape, hsizes))
if img.dtype == np.dtype('float32'):
ftype, ctype = np.dtype('float32'), np.dtype('complex64')
else:
ftype, ctype = np.dtype('float64'), np.dtype('complex128')
try:
import pyfftw
except ImportError:
from numpy.fft import rfftn, irfftn
empty = np.empty
use_fftw = False
else:
# Cache PyFFTW planning for 5 seconds
empty = pyfftw.empty_aligned
use_fftw = True
# Build working and output arrays
kernel = empty(pshape, dtype=ftype)
output = empty(img.shape + (len(stencils),), dtype=ftype)
if use_fftw:
# Need to create output arrays and plan both FFTs
krfft = empty(pshape[:-1] + (pshape[-1] // 2 + 1,), dtype=ctype)
rfftn = pyfftw.FFTW(kernel, krfft, axes=(0, 1, 2))
irfftn = pyfftw.FFTW(krfft, kernel,
axes=(0, 1, 2), direction='FFTW_BACKWARD')
m,n,p = img.shape
# Copy the image, leaving space for boundaries
kernel[:,:,:] = 0.
kernel[:m,:n,:p] = img
# For right boundaries, watch for running off left end with small arrays
for ax, (ld, hl) in enumerate(zip(img.shape, hsizes)):
# Build the slice for boundary values
lslices = [slice(None)]*3
rslices = [slice(None)]*3
# Left boundaries are straightforward
lslices[ax] = slice(hl, 0, -1)
rslices[ax] = slice(-hl, None)
kernel[rslices] = kernel[lslices]
# Don't walk off left edge when mirroring right boundary
hi = ld - 1
lo = max(hi - hl, 0)
lslices[ax] = slice(lo, hi)
rslices[ax] = slice(2 * hi - lo, hi, -1)
kernel[rslices] = kernel[lslices]
# Compute the image FFT
if use_fftw:
rfftn.execute()
imfft = krfft.copy()
else: imfft = rfftn(kernel)
i,j,k = hsizes
t,u,v = stencils[0].shape
for l, stencil in enumerate(stencils):
# Clear the kernel storage and copy the stencil
kernel[:,:,:] = 0.
kernel[:t,:u,:v] = stencil[::-1,::-1,::-1]
if use_fftw:
rfftn.execute()
krfft[:,:,:] *= imfft
irfftn(normalise_idft=True)
else: kernel = irfftn(rfftn(kernel) * imfft)
output[:,:,:,l] = kernel[i:i+m,j:j+n,k:k+p]
return output
def get_real_image(self):
if self.image is None:
self.image = irfftn(self.ft, self.imageshape)
return self.image
def weightedfftconvolve(in1, in2, mode="full", weighting='none', displayplots=False):
"""Convolve two N-dimensional arrays using FFT.
Convolve `in1` and `in2` using the fast Fourier transform method, with
the output size determined by the `mode` argument.
This is generally much faster than `convolve` for large arrays (n > ~500),
but can be slower when only a few output values are needed, and can only
output float arrays (int or object array inputs will be cast to float).
Parameters
----------
in1 : array_like
First input.
in2 : array_like
Second input. Should have the same number of dimensions as `in1`;
if sizes of `in1` and `in2` are not equal then `in1` has to be the
larger array.
mode : str {'full', 'valid', 'same'}, optional
A string indicating the size of the output:
``full``
The output is the full discrete linear convolution
of the inputs. (Default)
``valid``
The output consists only of those elements that do not
rely on the zero-padding.
``same``
The output is the same size as `in1`, centered
with respect to the 'full' output.
Returns
-------
out : array
An N-dimensional array containing a subset of the discrete linear
convolution of `in1` with `in2`.
"""
in1 = np.asarray(in1)
in2 = np.asarray(in2)
if np.isscalar(in1) and np.isscalar(in2): # scalar inputs
return in1 * in2
elif not in1.ndim == in2.ndim:
raise ValueError("in1 and in2 should have the same rank")
elif in1.size == 0 or in2.size == 0: # empty arrays
return np.array([])
s1 = np.array(in1.shape)
s2 = np.array(in2.shape)
complex_result = (np.issubdtype(in1.dtype, np.complex) or
np.issubdtype(in2.dtype, np.complex))
size = s1 + s2 - 1
if mode == "valid":
_check_valid_mode_shapes(s1, s2)
# Always use 2**n-sized FFT
fsize = 2 ** np.ceil(np.log2(size)).astype(int)
fslice = tuple([slice(0, int(sz)) for sz in size])
if not complex_result:
fft1 = rfftn(in1, fsize)
fft2 = rfftn(in2, fsize)
theorigmax = np.max(np.absolute(irfftn(gccproduct(fft1, fft2, 'none'), fsize)[fslice]))
ret = irfftn(gccproduct(fft1, fft2, weighting, displayplots=displayplots), fsize)[fslice].copy()
ret = irfftn(gccproduct(fft1, fft2, weighting, displayplots=displayplots), fsize)[fslice].copy()
ret = ret.real
ret *= theorigmax / np.max(np.absolute(ret))
else:
fft1 = fftpack.fftn(in1, fsize)
fft2 = fftpack.fftn(in2, fsize)
theorigmax = np.max(np.absolute(fftpack.ifftn(gccproduct(fft1, fft2, 'none'))[fslice]))
ret = fftpack.ifftn(gccproduct(fft1, fft2, weighting, displayplots=displayplots))[fslice].copy()
ret *= theorigmax / np.max(np.absolute(ret))
# scale to preserve the maximum
if mode == "full":
return ret
elif mode == "same":
return _centered(ret, s1)
elif mode == "valid":
return _centered(ret, s1 - s2 + 1)
def smooth(self, inimage, clean=False, is_fft=False):
"""
:Parameters:
inimage : `core.api.Image`
The image to be smoothed
clean : ``bool``
Should we call ``nan_to_num`` on the data before smoothing?
is_fft : ``bool``
Has the data already been fft'd?
:Returns: `Image`
"""
if inimage.ndim == 4:
_out = np.zeros(inimage.shape)
nslice = inimage.shape[0]
elif inimage.ndim == 3:
nslice = 1
else:
raise NotImplementedError, 'expecting either 3 or 4-d image.'
for _slice in range(nslice):
if inimage.ndim == 4:
data = inimage[_slice]
elif inimage.ndim == 3:
data = inimage[:]
if clean:
data = np.nan_to_num(data)
if not is_fft:
data = self._presmooth(data)
data *= self.fkernel
else:
data *= self.fkernel
data = fft.irfftn(data) / self.norms[self.normalization]
gc.collect()
_dslice = [slice(0, self.bshape[i], 1) for i in range(3)]
if self.scale != 1:
data = self.scale * data[_dslice]
if self.location != 0.0:
data += self.location
gc.collect()
# Write out data
if inimage.ndim == 4:
_out[_slice] = data
else:
_out = data
_slice += 1
gc.collect()
_out = _out[[slice(self._kernel.shape[i]/2, self.bshape[i] +
self._kernel.shape[i]/2) for i in range(len(self.bshape))]]
if inimage.ndim == 3:
return Image(_out, coordmap=self.coordmap)
else:
concat_affine = AffineTransform.identity('concat')
return Image(_out, coordmap=product(self.coordmap, concat_affine))
def correlate_windows(window_a,
window_b,
corr_method='fft',
nfftx=None,
nffty=None,
nfftz=None):
"""Compute correlation function between two interrogation windows.
The correlation function can be computed by using the correlation
theorem to speed up the computation.
Parameters
----------
window_a : 2d np.ndarray
a two dimensions array for the first interrogation window,
window_b : 2d np.ndarray
a two dimensions array for the second interrogation window.
corr_method : string
one method is currently implemented: 'fft'.
nfftx : int
the size of the 2D FFT in x-direction,
[default: 2 x windows_a.shape[0] is recommended].
nffty : int
the size of the 2D FFT in y-direction,
[default: 2 x windows_a.shape[1] is recommended].
nfftz : int
the size of the 2D FFT in z-direction,
[default: 2 x windows_a.shape[2] is recommended].
Returns
-------
corr : 3d np.ndarray
a three dimensional array of the correlation function.
Note that due to the wish to use 2^N windows for faster FFT
we use a slightly different convention for the size of the
correlation map. The theory says it is M+N-1, and the
'direct' method gets this size out
the FFT-based method returns M+N size out, where M is the window_size
and N is the search_area_size
It leads to inconsistency of the output
"""
if corr_method == 'fft':
window_b = np.conj(window_b[::-1, ::-1, ::-1])
if nfftx is None:
nfftx = nextpower2(window_b.shape[0] + window_a.shape[0])
if nffty is None:
nffty = nextpower2(window_b.shape[1] + window_a.shape[1])
if nfftz is None:
nfftz = nextpower2(window_b.shape[2] + window_a.shape[2])
f2a = rfftn(normalize_intensity(window_a), s=(nfftx, nffty, nfftz))
f2b = rfftn(normalize_intensity(window_b), s=(nfftx, nffty, nfftz))
corr = irfftn(f2a * f2b).real
corr = corr[:window_a.shape[0] +
window_b.shape[0], :window_b.shape[1] +
window_a.shape[1], :window_b.shape[2] + window_a.shape[2]]
return corr
# elif corr_method == 'direct':
# return convolve2d(normalize_intensity(window_a),
# normalize_intensity(window_b[::-1, ::-1, ::-1]), 'full')
else:
raise ValueError('method is not implemented')