Beispiel #1
0
header['radius'] = 1.2
obj = siddon.simu.object_from_header(header)
obj[:] = siddon.phantom.shepp_logan(obj.shape)
# data 
image_header = {'n_images':60,
                'SIMPLE':True, 'BITPIX':-64,
                'NAXIS1':128, 'NAXIS2':128,
                'CRPIX1':64, 'CRPIX2':64,
                'CDELT1':6e-5, 'CDELT2':6e-5,
                'CRVAL1':0., 'CRVAL2':0.,
                }
image_header['radius'] = 200.
data = siddon.simu.circular_trajectory_data(**image_header)
data[:] = np.zeros(data.shape)
# projector
P = siddon.siddon_lo(data.header, obj.header)
# projection
t = time.time()
data = siddon.projector(data, obj)
print("projection time : " + str(time.time() - t))
# data
y = data.flatten()
# backprojection
t = time.time()
x0 = P.T * y
bpj = x0.reshape(obj.shape)
print("projection time : " + str(time.time() - t))
# coverage map
weights = (P.T * np.ones(y.size)).reshape(obj.shape)
# priors
Ds = [lo.diff(obj.shape, axis=i) for i in xrange(3)]
# data 
path = os.path.join(os.getenv('HOME'), 'data', '171dec08')
obsrvtry = 'STEREO_A'
time_window = ['2008-12-01T00:00:00.000', '2008-12-03T00:00:00.000']
# one image every time_step seconds
time_step = 4 * 3600.
data = siddon.secchi.read_data(path, bin_factor=4,
                               obsrvtry=obsrvtry,
                               time_window=time_window, 
                               time_step=time_step)
# cube
shape = 3 * (128,)
header = {'CRPIX1':64., 'CRPIX2':64., 'CRPIX3':64.,
          'CDELT1':0.0234375, 'CDELT2':0.0234375, 'CDELT3':0.0234375,
          'CRVAL1':0., 'CRVAL2':0., 'CRVAL3':0.,}
cube = fa.zeros(shape, header=header)
# model
P = siddon.siddon_lo(data.header, cube.header)
D = [lo.diff(cube.shape, axis=i) for i in xrange(cube.ndim)]
hypers = cube.ndim * (1e0, )
# inversion
t = time.time()
A = P.T * P + np.sum([h * d.T * d for h, d in zip(hypers, D)])
b = P.T * data.flatten()
#callback = lo.iterative.CallbackFactory(verbose=True)
#x, info = spl.bicgstab(A, b, maxiter=100, callback=callback)
x, info = lo.acg(P, data.flatten(), D, hypers, maxiter=100,)
sol = cube.copy()
sol[:] = x.reshape(cube.shape)
print(time.time() - t)