def test_stspa_spiral(self):
target, sens = self.problem_2d(8)
fov = 0.55
gts = 6.4e-6
gslew = 190
gamp = 40
R = 1
dx = 0.025 # in m
# construct a trajectory
g, k, t, s = rf.spiral_arch(fov / R, dx, gts, gslew, gamp)
A = linop.Sense(sens, coord=k, ishape=target.shape).H
pulses = rf.stspa(target,
sens,
k,
dt=4e-6,
alpha=1,
b0=None,
st=None,
explicit=False,
max_iter=100,
tol=1E-4)
npt.assert_array_almost_equal(A * pulses, target, 1E-3)
def test_stspa_radial(self):
target, sens = self.problem_2d(8)
# makes dim*dim*2 trajectory
traj = sp.mri.radial((sens.shape[1], sens.shape[1], 2),
target.shape,
golden=True,
dtype=np.float)
# reshape to be Nt*2 trajectory
traj = np.reshape(traj, [traj.shape[0] * traj.shape[1], 2])
A = linop.Sense(sens, coord=traj, weights=None, ishape=target.shape).H
pulses = rf.stspa(target,
sens,
traj,
dt=4e-6,
alpha=1,
b0=None,
st=None,
explicit=False,
max_iter=100,
tol=1E-4)
npt.assert_array_almost_equal(A * pulses, target, 1E-3)