def get_data(subj, mask, sessions=None, dtype='jacobian'):
"""
Parameters
----------
subj : (N,) list of img_like
mask : Niimg_like
sessions : list of str
Returns
-------
data : (N x M) np.ndarray
Data extracted from ``imgs``, where ``M`` is the number of parcels in
``mask``
"""
# check mask is correct
if not isinstance(mask, BaseMasker):
if not isinstance(mask, str):
raise ValueError('Mask must be a mask object or filepath.')
if 'probabilistic' in mask:
mask = NiftiMapsMasker(mask, resampling_target='maps')
else:
mask = NiftiLabelsMasker(mask, resampling_target='labels')
# only fit mask if it hasn't been fitted to save time
if not hasattr(mask, 'maps_img_'):
mask = mask.fit()
# get images for supplied sessions (or all images)
subj_dir = pjoin(DERIV_DIR, subj)
if sessions is not None:
imgs = list(
itertools.chain.from_iterable(
[glob.glob(pjoin(subj_dir, f'*_ses-{ses}_*_{dtype}.nii.gz'))
for ses in sorted(sessions)]
)
)
else:
imgs = sorted(glob.glob(pjoin(subj_dir, '*{dtype}.nii.gz')))
# extract subject / session information from data (BIDS format)
demo = np.row_stack([REGEX.findall(i) for i in imgs])
# fit mask to data and stack across sessions
data = np.row_stack([mask.transform(check_niimg(img, atleast_4d=True))
for img in imgs])
return data, demo
# dump network projections
###############################################################################
# retrieve network projections
from nilearn import datasets as ds
smith_pkg = ds.fetch_atlas_smith_2009()
icas_path = smith_pkg['rsn20']
from nilearn.input_data import NiftiMapsMasker
nmm = NiftiMapsMasker(
mask_img=mask_file, maps_img=icas_path, resampling_target='mask',
standardize=True, detrend=True)
nmm.fit()
nmm.maps_img_.to_filename('dbg_ica_maps.nii.gz')
FS_netproj = nmm.transform(all_sub_rs_maps)
np.save('%i_nets_timeseries' % sub_id, FS_netproj)
# compute network sparse inverse covariance
from sklearn.covariance import GraphLassoCV
from nilearn.image import index_img
from nilearn import plotting
try:
gsc_nets = GraphLassoCV(verbose=2, alphas=20)
gsc_nets.fit(FS_netproj)
np.save('%i_nets_cov' % sub_id, gsc_nets.covariance_)
np.save('%i_nets_prec' % sub_id, gsc_nets.precision_)
except:
pass
labels = atlas['labels']
# Load the functional datasets
data = datasets.fetch_development_fmri(n_subjects=1)
print('First subject resting-state nifti image (4D) is located at: %s' %
data.func[0])
############################################################################
# Extract the time series
# ------------------------
from nilearn.input_data import NiftiMapsMasker
masker = NiftiMapsMasker(maps_img=atlas_filename, standardize=True,
memory='nilearn_cache', verbose=5)
masker.fit(data.func[0])
time_series = masker.transform(data.func[0],
confounds=data.confounds)
############################################################################
# We can generate an HTML report and visualize the components of the
# :class:`~nilearn.input_data.NiftiMapsMasker`.
# You can pass the indices of the spatial maps you want to include in the
# report in the order you want them to appear.
# Here, we only include maps 2, 6, 7, 16, and 21 in the report:
report = masker.generate_report(displayed_maps=[2, 6, 7, 16, 21])
report
############################################################################
# `time_series` is now a 2D matrix, of shape (number of time points x
# number of regions)
print(time_series.shape)
# We study only 60 subjects from the dataset, to save computation time.
from nilearn import datasets
development_dataset = datasets.fetch_development_fmri(n_subjects=60)
###############################################################################
# We use probabilistic regions of interest (ROIs) from the MSDL atlas.
from nilearn.input_data import NiftiMapsMasker
msdl_data = datasets.fetch_atlas_msdl()
msdl_coords = msdl_data.region_coords
masker = NiftiMapsMasker(
msdl_data.maps, resampling_target="data", t_r=2, detrend=True,
low_pass=.1, high_pass=.01, memory='nilearn_cache', memory_level=1).fit()
masked_data = [masker.transform(func, confounds) for
(func, confounds) in zip(
development_dataset.func, development_dataset.confounds)]
###############################################################################
# What kind of connectivity is most powerful for classification?
# --------------------------------------------------------------
# we will use connectivity matrices as features to distinguish children from
# adults. We use cross-validation and measure classification accuracy to
# compare the different kinds of connectivity matrices.
# prepare the classification pipeline
from sklearn.pipeline import Pipeline
from nilearn.connectome import ConnectivityMeasure
from sklearn.svm import LinearSVC
from sklearn.dummy import DummyClassifier
# -*- coding: utf-8 -*- """ Created on Mon Jun 1 10:21:42 2015 @author: mr243268 """ from embedding import CovEmbedding, vec_to_sym from nilearn.datasets import fetch_nyu_rest, fetch_msdl_atlas from nilearn.input_data import NiftiMapsMasker dataset = fetch_nyu_rest(n_subjects=1) atlas = fetch_msdl_atlas() masker = NiftiMapsMasker(atlas['maps'], detrend=True, standardize=True) masker.fit() ts = masker.transform(dataset.func[0]) cov_embed = CovEmbedding(kind='tangent') output = cov_embed.fit_transform([ts]) m = vec_to_sym(output)
from nilearn.datasets import fetch_atlas_msdl, fetch_cobre
from nilearn.input_data import NiftiMapsMasker
from nilearn.connectome import vec_to_sym_matrix
from nilearn.plotting import plot_matrix
from posce import PopulationShrunkCovariance
# fetch atlas
msdl = fetch_atlas_msdl()
# fetch rfMRI scans from cobre dataset
cobre = fetch_cobre(n_subjects=20)
# extract timeseries
masker = NiftiMapsMasker(msdl.maps,
detrend=True,
standardize=True,
verbose=1,
memory=".")
masker.fit()
ts = [masker.transform(f) for f in cobre.func]
# compute PoSCE on the same dataset
posce = PopulationShrunkCovariance(shrinkage=1e-2)
posce.fit(ts)
connectivities = posce.transform(ts)
# plot the first shrunk covariance
cov = vec_to_sym_matrix(connectivities[0])
plot_matrix(cov)
from nilearn.input_data import NiftiMapsMasker
import numpy as np
msdl = datasets.fetch_atlas_msdl()
print('number of regions in MSDL atlas:', len(msdl.labels))
masker = NiftiMapsMasker(msdl.maps,
resampling_target="data",
t_r=2,
detrend=True,
low_pass=.1,
high_pass=.01,
memory='nilearn_cache',
memory_level=3).fit([])
masked_data = [
masker.transform(func, confounds)
for (func, confounds) in zip(rest_data.func, rest_data.confounds)
]
masked_data = np.asarray(masked_data)
print('masked data shape:', masked_data[0].shape)
###############################################################################
# Compute and plot connectivity matrix
from nilearn.connectome import ConnectivityMeasure
correlation_measure = ConnectivityMeasure(kind='correlation').fit(masked_data)
plotting.plot_matrix(correlation_measure.mean_, tri='lower')
###############################################################################