def test_create_unit_sphere():
v, e, t = create_unit_sphere(7)
assert_array_equal(v[::2], -v[1::2])
assert_array_equal(v[e[::2]], -v[e[1::2]])
assert_array_equal(v[e[t[::2]]], -v[e[t[1::2]]])
assert_array_almost_equal((v * v).sum(1), 1)
assert_array_equal(e[t, 0], np.roll(e[t, 1], 1, 1))
def get_vertex_set(key):
if key[:6] == 'create':
number = eval(key[6:])
vertices, edges, faces = create_unit_sphere(number)
omit = 0
return vertices
else:
entry = sphere_dic[key]
if entry.has_key('omit'):
omit = entry['omit']
else:
omit = 0
filepath = entry['filepath']
if entry['object'] == 'npz':
filearray = np.load(filepath)
vertices = filearray[entry['vertices']]
elif sphere_dic[key]['object'] == 'npy':
vertices = np.load(filepath)
elif entry['object'] == 'dicom':
data,affine,bvals,gradients=dcm.read_mosaic_dir(filepath)
#print (bvals.shape, gradients.shape)
grad3 = np.vstack((bvals,bvals,bvals)).transpose()
#print grad3.shape
#vertices = grad3*gradients
vertices = gradients
if omit > 0:
vertices = vertices[omit:,:]
if entry['hemi']:
vertices = np.vstack([vertices, -vertices])
return vertices[omit:,:]
def main():
#set some values to be used later
sh_order = 6
verts, edges, efaces = create_unit_sphere(4)
#read_data from disk
data, fa, bvec, bval, voxel_size = sample_hardi_data()
data_slice = data[32:76, 32:76, 26:27]
fa_slice = fa[32:76, 32:76, 26]
#normalize data by dividing by b0, this is needed so we can take log later
norm_data = normalize_data(data_slice, bval, min_signal=1)
#create an instance of the model
model_instance = MonoExpOpdfModel(sh_order, bval, bvec, .006)
model_instance.set_sampling_points(verts, edges)
#use the model it fit the data
opdfs_sampled_at_verts = model_instance.evaluate(norm_data)
opdfs_sph_harm_coef = model_instance.fit_data(norm_data)
#display the opdf blobs using mayavi
faces = edges[efaces, 0]
show_blobs(opdfs_sampled_at_verts, verts, faces)
mlab.imshow(fa_slice, colormap='gray', interpolate=False)
mlab.show()
def get_vertex_set(key):
if key[:6] == 'create':
number = eval(key[6:])
vertices, edges, faces = create_unit_sphere(number)
omit = 0
else:
entry = sphere_dic[key]
#print entry
if entry.has_key('omit'):
omit = entry['omit']
else:
omit = 0
filepath = entry['filepath']
if entry['object'] == 'npz':
filearray = np.load(filepath)
vertices = filearray[entry['vertices']]
elif sphere_dic[key]['object'] == 'npy':
vertices = np.load(filepath)
elif entry['object'] == 'dicom':
data, affine, bvals, gradients = dcm.read_mosaic_dir(filepath)
#print (bvals.shape, gradients.shape)
grad3 = np.vstack((bvals, bvals, bvals)).transpose()
#print grad3.shape
#vertices = grad3*gradients
vertices = gradients
if omit > 0:
vertices = vertices[omit:, :]
if entry['hemi']:
vertices = np.vstack([vertices, -vertices])
print key, ': number of vertices = ', vertices.shape[
0], '(drop ', omit, ')'
return vertices[omit:, :]
def test_create_unit_sphere():
v, e, t = create_unit_sphere(7)
assert_array_equal(v[::2], -v[1::2])
assert_array_equal(v[e[::2]], -v[e[1::2]])
assert_array_equal(v[e[t[::2]]], -v[e[t[1::2]]])
assert_array_almost_equal((v*v).sum(1), 1)
assert_array_equal(e[t,0], np.roll(e[t, 1], 1, 1))
from sphdif.coord import car2sph, sph2car
from dipy.sims.voxel import multi_tensor_odf
from dipy.reconst.shm import SlowAdcOpdfModel, MonoExpOpdfModel, QballOdfModel
coords = sph_io.load('sphere_pts.npz')
#from dipy.data import get_sphere
#verts, faces = get_sphere('symmetric724')
## from dipy.core.triangle_subdivide import create_unit_sphere
## verts, edges, sides = create_unit_sphere(5)
## faces = edges[sides, 0]
from dipy.core.triangle_subdivide import create_unit_sphere
verts, edges, sides = create_unit_sphere(5)
faces = edges[sides, 0]
theta, phi, r = car2sph(*verts.T)
sampling_xyz = np.column_stack(
sph2car(coords['gradient_theta'], coords['gradient_phi'])
)
## verts = np.column_stack(sph2car(theta, phi))
## from dipy.core.meshes import faces_from_vertices
## faces = faces_from_vertices(verts)
def separation_from_odf(odf):
# Find angles
def create_half_unit_sphere():
v, e, t = create_unit_sphere(7)
assert_array_almost_equal((v * v).sum(1), 1)
assert_array_equal(e[t, 0], np.roll(e[t, 1], 1, 1))
def create_half_unit_sphere():
v, e, t = create_unit_sphere(7)
assert_array_almost_equal((v*v).sum(1), 1)
assert_array_equal(e[t,0], np.roll(e[t, 1], 1, 1))
import numpy as np from dipy.core.reconstruction_performance import peak_finding from dipy.core.reconstruction_performance import pf_bago from dipy.core.triangle_subdivide import create_unit_sphere, remove_half_sphere v, e, t = create_unit_sphere(5) vH, eH, tH = remove_half_sphere(v, e, t) odf = np.random.random(len(vH)) pB, iB = pf_bago(odf, eH) bO = np.r_[odf, odf] faces = e[t, 0] faces = faces / 2 + (faces % 2) * len(odf) p, i = peak_finding(bO, faces)
# ================
# Q-Space Sampling
# ================
# Note: We sample our signal in Q-space on the low-order quadrature points
# here, but wwe could just as well have used other, random points on the
# sphere.
E = w[0] * single_tensor(gradients=xyz, bvals=b, S0=1, rotation=R0, SNR=SNR)
E += w[1] * single_tensor(gradients=xyz, bvals=b, S0=1, rotation=R1, SNR=SNR)
print "Signal mean:", E.mean()
if visualize_signal:
from dipy.core.triangle_subdivide import create_unit_sphere
sphere = create_unit_sphere(6)
bb = np.ones(len(sphere.vertices)) * b.mean()
E_ = w[0] * single_tensor(gradients=sphere.vertices, bvals=bb, S0=1, rotation=R0, SNR=SNR)
E_ += w[1] * single_tensor(gradients=sphere.vertices, bvals=bb, S0=1, rotation=R1, SNR=SNR)
ODF = w[0] * single_tensor_ODF(sphere.vertices, rotation=R0)
ODF += w[1] * single_tensor_ODF(sphere.vertices, rotation=R1)
from dipy.viz import show_odfs
show_odfs([[[E_, ODF]]], (sphere.vertices, sphere.faces))
if visualize_odf:
plot_ODF(grid_density=D)
mlab = plot.get_mlab()
