def apply_mask_all(subject_id, bold):
import nibabel as nb
import pylab as pl
from nilearn.masking import _load_mask_img, compute_epi_mask, apply_mask, _unmask_nd, _apply_mask_fmri
from nilearn import _utils, resampling
from nilearn._utils.ndimage import largest_connected_component
from nilearn._utils.cache_mixin import cache
ra = '/gablab/p/eegfmri/analysis/iaps/pilot%s/segstats/right_amygdala_mask_2.nii.gz' %(subject_id)
ra = nb.load(ra)
la = '/gablab/p/eegfmri/analysis/iaps/pilot%s/segstats/left_amygdala_mask_2.nii.gz' %(subject_id)
la = nb.load(la)
# f = _apply_mask_fmri(bold_1, b) and NiftiMasker do not work -- doing this manually:
rd = _utils.as_ndarray(ra.get_data(),dtype=np.bool)
ld = _utils.as_ndarray(la.get_data(),dtype=np.bool)
rl = rd+ld
mask_img = ra # or la
mask_data = rl
mask_affine = mask_img.get_affine() # gets only affine of ra
print 'Mask [ra] affine'
print mask_affine
print 'fMRI affine'
print affine
data = bold.get_data()
series = _utils.as_ndarray(data, order="C", copy=True)
X = series[mask_data].T
# mask_img = mask_data.get_data()
print 'Masked Data', X.shape
return X, mask_data
def generate_random_img(shape, length=1, affine=np.eye(4),
rand_gen=np.random.RandomState(0)):
data = rand_gen.randn(*(shape + (length,)))
return nibabel.Nifti1Image(data, affine), nibabel.Nifti1Image(
as_ndarray(data[..., 0] > 0.2, dtype=np.int8), affine)
def find_cut_coords(img, mask=None, activation_threshold=None):
import warnings
import numpy as np
from scipy import ndimage
from nilearn._utils import as_ndarray, new_img_like
from nilearn._utils.ndimage import largest_connected_component
from nilearn._utils.extmath import fast_abs_percentile
""" Find the center of the largest activation connected component.
Parameters
-----------
img : 3D Nifti1Image
The brain map.
mask : 3D ndarray, boolean, optional
An optional brain mask.
activation_threshold : float, optional
The lower threshold to the positive activation. If None, the
activation threshold is computed using the 80% percentile of
the absolute value of the map.
Returns
-------
x : float
the x world coordinate.
y : float
the y world coordinate.
z : float
the z world coordinate.
"""
data = img.get_data()
# To speed up computations, we work with partial views of the array,
# and keep track of the offset
offset = np.zeros(3)
# Deal with masked arrays:
if hasattr(data, 'mask'):
not_mask = np.logical_not(data.mask)
if mask is None:
mask = not_mask
else:
mask *= not_mask
data = np.asarray(data)
# Get rid of potential memmapping
data = as_ndarray(data)
my_map = data.copy()
if mask is not None:
slice_x, slice_y, slice_z = ndimage.find_objects(mask)[0]
my_map = my_map[slice_x, slice_y, slice_z]
mask = mask[slice_x, slice_y, slice_z]
my_map *= mask
offset += [slice_x.start, slice_y.start, slice_z.start]
# Testing min and max is faster than np.all(my_map == 0)
if (my_map.max() == 0) and (my_map.min() == 0):
return .5 * np.array(data.shape)
if activation_threshold is None:
activation_threshold = fast_abs_percentile(my_map[my_map != 0].ravel(),
80)
mask = np.abs(my_map) > activation_threshold - 1.e-15
# mask may be zero everywhere in rare cases
if mask.max() == 0:
return .5 * np.array(data.shape)
mask = largest_connected_component(mask)
slice_x, slice_y, slice_z = ndimage.find_objects(mask)[0]
my_map = my_map[slice_x, slice_y, slice_z]
mask = mask[slice_x, slice_y, slice_z]
my_map *= mask
offset += [slice_x.start, slice_y.start, slice_z.start]
# For the second threshold, we use a mean, as it is much faster,
# althought it is less robust
second_threshold = np.abs(np.mean(my_map[mask]))
second_mask = (np.abs(my_map) > second_threshold)
if second_mask.sum() > 50:
my_map *= largest_connected_component(second_mask)
cut_coords = ndimage.center_of_mass(np.abs(my_map))
x_map, y_map, z_map = cut_coords + offset
coords = []
coords.append(x_map)
coords.append(y_map)
coords.append(z_map)
# Return as a list of scalars
return coords
def fit(self, imgs, y, data_train=None):
"""Fit the searchlight
Parameters
----------
img : Niimg-like object
See http://nilearn.github.io/building_blocks/manipulating_mr_images.html#niimg.
4D image.
y : 1D array-like
Target variable to predict. Must have exactly as many elements as
3D images in img.
data_train : np.array, optional
Data to train on, if data for training is different from X.
Attributes
----------
`scores_` : numpy.ndarray
search_light scores. Same shape as input parameter
process_mask_img.
"""
# Compute world coordinates of all in-mask voxels.
mask, mask_affine = masking._load_mask_img(self.mask_img)
mask_coords = np.where(mask != 0)
mask_coords = np.asarray(mask_coords + (np.ones(len(mask_coords[0]),
dtype=np.int),))
mask_coords = np.dot(mask_affine, mask_coords)[:3].T
# Compute world coordinates of all in-process mask voxels
if self.process_mask_img is None:
process_mask = mask
process_mask_coords = mask_coords
else:
process_mask, process_mask_affine = \
masking._load_mask_img(self.process_mask_img)
process_mask_coords = np.where(process_mask != 0)
process_mask_coords = \
np.asarray(process_mask_coords
+ (np.ones(len(process_mask_coords[0]),
dtype=np.int),))
process_mask_coords = np.dot(process_mask_affine,
process_mask_coords)[:3].T
clf = neighbors.NearestNeighbors(radius=self.radius)
A = clf.fit(mask_coords).radius_neighbors_graph(process_mask_coords)
del process_mask_coords, mask_coords
A = A.tolil()
# scores is an 1D array of CV scores with length equals to the number
# of voxels in processing mask (columns in process_mask)
X = masking._apply_mask_fmri(imgs,
nibabel.Nifti1Image(as_ndarray(mask, dtype=np.int8),
mask_affine))
estimator = self.estimator
if isinstance(estimator, basestring):
estimator = ESTIMATOR_CATALOG[estimator]()
# From here starts Dima's modifications, added nii_optional argument
# to .fit method
if data_train is None:
scores = search_light(X, y, estimator, A,
self.scoring, self.cv, self.n_jobs,
self.verbose)
else:
scores = search_light(X, y, estimator, A,
self.scoring, self.cv, self.n_jobs,
self.verbose, data_train)
scores_3D = np.zeros(process_mask.shape)
scores_3D[process_mask] = scores
self.scores_ = scores_3D
return self
def find_cut_coords(img, mask=None, activation_threshold=None):
import warnings
import numpy as np
from scipy import ndimage
from nilearn._utils import as_ndarray, new_img_like
from nilearn._utils.ndimage import largest_connected_component
from nilearn._utils.extmath import fast_abs_percentile
""" Find the center of the largest activation connected component.
Parameters
-----------
img : 3D Nifti1Image
The brain map.
mask : 3D ndarray, boolean, optional
An optional brain mask.
activation_threshold : float, optional
The lower threshold to the positive activation. If None, the
activation threshold is computed using the 80% percentile of
the absolute value of the map.
Returns
-------
x : float
the x world coordinate.
y : float
the y world coordinate.
z : float
the z world coordinate.
"""
data = img.get_data()
# To speed up computations, we work with partial views of the array,
# and keep track of the offset
offset = np.zeros(3)
# Deal with masked arrays:
if hasattr(data, 'mask'):
not_mask = np.logical_not(data.mask)
if mask is None:
mask = not_mask
else:
mask *= not_mask
data = np.asarray(data)
# Get rid of potential memmapping
data = as_ndarray(data)
my_map = data.copy()
if mask is not None:
slice_x, slice_y, slice_z = ndimage.find_objects(mask)[0]
my_map = my_map[slice_x, slice_y, slice_z]
mask = mask[slice_x, slice_y, slice_z]
my_map *= mask
offset += [slice_x.start, slice_y.start, slice_z.start]
# Testing min and max is faster than np.all(my_map == 0)
if (my_map.max() == 0) and (my_map.min() == 0):
return .5 * np.array(data.shape)
if activation_threshold is None:
activation_threshold = fast_abs_percentile(my_map[my_map != 0].ravel(),
80)
mask = np.abs(my_map) > activation_threshold - 1.e-15
# mask may be zero everywhere in rare cases
if mask.max() == 0:
return .5 * np.array(data.shape)
mask = largest_connected_component(mask)
slice_x, slice_y, slice_z = ndimage.find_objects(mask)[0]
my_map = my_map[slice_x, slice_y, slice_z]
mask = mask[slice_x, slice_y, slice_z]
my_map *= mask
offset += [slice_x.start, slice_y.start, slice_z.start]
# For the second threshold, we use a mean, as it is much faster,
# althought it is less robust
second_threshold = np.abs(np.mean(my_map[mask]))
second_mask = (np.abs(my_map) > second_threshold)
if second_mask.sum() > 50:
my_map *= largest_connected_component(second_mask)
cut_coords = ndimage.center_of_mass(np.abs(my_map))
x_map, y_map, z_map = cut_coords + offset
coords = []
coords.append(x_map)
coords.append(y_map)
coords.append(z_map)
# Return as a list of scalars
return coords
def generate_random_img(shape, length=1, affine=np.eye(4),
rand_gen=np.random.RandomState(0)):
data = rand_gen.randn(*(shape + (length,)))
return nibabel.Nifti1Image(data, affine), nibabel.Nifti1Image(
as_ndarray(data[..., 0] > 0.2, dtype=np.int8), affine)
