def test_ward_agglomeration():
"""
Check that we obtain the correct solution in a simplistic case
"""
rnd = np.random.RandomState(0)
mask = np.ones([10, 10], dtype=np.bool)
X = rnd.randn(50, 100)
connectivity = grid_to_graph(*mask.shape)
assert_warns(DeprecationWarning, WardAgglomeration)
with warnings.catch_warnings(record=True) as warning_list:
warnings.simplefilter("always", DeprecationWarning)
if hasattr(np, 'VisibleDeprecationWarning'):
# Let's not catch the numpy internal DeprecationWarnings
warnings.simplefilter('ignore', np.VisibleDeprecationWarning)
ward = WardAgglomeration(n_clusters=5, connectivity=connectivity)
ward.fit(X)
assert_equal(len(warning_list), 1)
agglo = FeatureAgglomeration(n_clusters=5, connectivity=connectivity)
agglo.fit(X)
assert_array_equal(agglo.labels_, ward.labels_)
assert_true(np.size(np.unique(agglo.labels_)) == 5)
X_red = agglo.transform(X)
assert_true(X_red.shape[1] == 5)
X_full = agglo.inverse_transform(X_red)
assert_true(np.unique(X_full[0]).size == 5)
assert_array_almost_equal(agglo.transform(X_full), X_red)
# Check that fitting with no samples raises a ValueError
assert_raises(ValueError, agglo.fit, X[:0])
def ward_adni_rs_fmri(func_files, n_clusters=200):
masker = NiftiMasker(mask_strategy='epi', mask_args=dict(opening=1))
masker.fit(func_files)
func_masked = masker.transform(func_files)
#func_masked = masker.transform_niimgs(func_files, n_jobs=4)
func_masked = np.vstack(func_masked)
###########################################################################
# Ward
###########################################################################
mask = masker.mask_img_.get_data().astype(np.bool)
shape = mask.shape
connectivity = image.grid_to_graph(n_x=shape[0],
n_y=shape[1],
n_z=shape[2],
mask=mask)
# Computing the ward for the first time, this is long...
ward = WardAgglomeration(n_clusters=n_clusters,
connectivity=connectivity,
memory='nilearn_cache')
ward.fit(func_masked)
ward_labels_unique = np.unique(ward.labels_)
ward_labels = ward.labels_
ward_filename = '_'.join(['ward', str(n_clusters)])
img_ward = masker.inverse_transform(ward.labels_)
img_ward.to_filename(os.path.join(CACHE_DIR, ward_filename))
def test_ward_agglomeration():
"""
Check that we obtain the correct solution in a simplistic case
"""
rnd = np.random.RandomState(0)
mask = np.ones([10, 10], dtype=np.bool)
X = rnd.randn(50, 100)
connectivity = grid_to_graph(*mask.shape)
assert_warns(DeprecationWarning, WardAgglomeration)
with warnings.catch_warnings(record=True) as warning_list:
warnings.simplefilter("always", DeprecationWarning)
if hasattr(np, 'VisibleDeprecationWarning'):
# Let's not catch the numpy internal DeprecationWarnings
warnings.simplefilter('ignore', np.VisibleDeprecationWarning)
ward = WardAgglomeration(n_clusters=5, connectivity=connectivity)
ward.fit(X)
assert_equal(len(warning_list), 1)
agglo = FeatureAgglomeration(n_clusters=5, connectivity=connectivity)
agglo.fit(X)
assert_array_equal(agglo.labels_, ward.labels_)
assert_true(np.size(np.unique(agglo.labels_)) == 5)
X_red = agglo.transform(X)
assert_true(X_red.shape[1] == 5)
X_full = agglo.inverse_transform(X_red)
assert_true(np.unique(X_full[0]).size == 5)
assert_array_almost_equal(agglo.transform(X_full), X_red)
# Check that fitting with no samples raises a ValueError
assert_raises(ValueError, agglo.fit, X[:0])
def test_ward_agglomeration():
"""
Check that we obtain the correct solution in a simplistic case
"""
rnd = np.random.RandomState(0)
mask = np.ones([10, 10], dtype=np.bool)
X = rnd.randn(50, 100)
connectivity = grid_to_graph(*mask.shape)
assert_warns(DeprecationWarning, WardAgglomeration)
with ignore_warnings():
ward = WardAgglomeration(n_clusters=5, connectivity=connectivity)
ward.fit(X)
agglo = FeatureAgglomeration(n_clusters=5, connectivity=connectivity)
agglo.fit(X)
assert_array_equal(agglo.labels_, ward.labels_)
assert_true(np.size(np.unique(agglo.labels_)) == 5)
X_red = agglo.transform(X)
assert_true(X_red.shape[1] == 5)
X_full = agglo.inverse_transform(X_red)
assert_true(np.unique(X_full[0]).size == 5)
assert_array_almost_equal(agglo.transform(X_full), X_red)
# Check that fitting with no samples raises a ValueError
assert_raises(ValueError, agglo.fit, X[:0])
def test_ward_agglomeration():
"""
Check that we obtain the correct solution in a simplistic case
"""
rng = np.random.RandomState(0)
mask = np.ones([10, 10], dtype=np.bool)
X = rng.randn(50, 100)
connectivity = grid_to_graph(*mask.shape)
assert_warns(DeprecationWarning, WardAgglomeration)
with ignore_warnings():
ward = WardAgglomeration(n_clusters=5, connectivity=connectivity)
ward.fit(X)
agglo = FeatureAgglomeration(n_clusters=5, connectivity=connectivity)
agglo.fit(X)
assert_array_equal(agglo.labels_, ward.labels_)
assert_true(np.size(np.unique(agglo.labels_)) == 5)
X_red = agglo.transform(X)
assert_true(X_red.shape[1] == 5)
X_full = agglo.inverse_transform(X_red)
assert_true(np.unique(X_full[0]).size == 5)
assert_array_almost_equal(agglo.transform(X_full), X_red)
# Check that fitting with no samples raises a ValueError
assert_raises(ValueError, agglo.fit, X[:0])
def prepare_data(imgs, connectivity, mask, n_clusters=5000, n_components=100):
# data preparation
Z = nifti_masker.fit_transform(imgs)
pca = RandomizedPCA(n_components=n_components)
Z_ = pca.fit_transform(Z.T).T
ward = WardAgglomeration(n_clusters=n_clusters, connectivity=connectivity,
memory='nilearn_cache').fit(Z_)
W = ward.transform(Z)
del Z
# data cube is a more convenient representation
cube = np.array([W[subject_label == subject]
for subject in np.arange(n_subjects)])
# parcel connectivity
parcel_connectivity = do_parcel_connectivity(mask, n_clusters, ward)
return cube, ward, parcel_connectivity
def prepare_data(imgs, connectivity, mask, n_clusters=5000, n_components=100):
# data preparation
Z = nifti_masker.fit_transform(imgs)
pca = RandomizedPCA(n_components=n_components)
Z_ = pca.fit_transform(Z.T).T
ward = WardAgglomeration(n_clusters=n_clusters,
connectivity=connectivity,
memory='nilearn_cache').fit(Z_)
W = ward.transform(Z)
del Z
# data cube is a more convenient representation
cube = np.array(
[W[subject_label == subject] for subject in np.arange(n_subjects)])
# parcel connectivity
parcel_connectivity = do_parcel_connectivity(mask, n_clusters, ward)
return cube, ward, parcel_connectivity
def test_ward_agglomeration():
"""
Check that we obtain the correct solution in a simplistic case
"""
rnd = np.random.RandomState(0)
mask = np.ones([10, 10], dtype=np.bool)
X = rnd.randn(50, 100)
connectivity = grid_to_graph(*mask.shape)
ward = WardAgglomeration(n_clusters=5, connectivity=connectivity)
ward.fit(X)
assert_true(np.size(np.unique(ward.labels_)) == 5)
Xred = ward.transform(X)
assert_true(Xred.shape[1] == 5)
Xfull = ward.inverse_transform(Xred)
assert_true(np.unique(Xfull[0]).size == 5)
def test_ward_agglomeration():
"""
Check that we obtain the correct solution in a simplistic case
"""
rnd = np.random.RandomState(0)
mask = np.ones([10, 10], dtype=np.bool)
X = rnd.randn(50, 100)
connectivity = grid_to_graph(*mask.shape)
ward = WardAgglomeration(n_clusters=5, connectivity=connectivity)
ward.fit(X)
assert_true(np.size(np.unique(ward.labels_)) == 5)
Xred = ward.transform(X)
assert_true(Xred.shape[1] == 5)
Xfull = ward.inverse_transform(Xred)
assert_true(np.unique(Xfull[0]).size == 5)
assert_array_almost_equal(ward.transform(Xfull), Xred)
# Mask data
epi_masked = epi_img[mask]
### Ward ######################################################################
# Compute connectivity matrix
from sklearn.feature_extraction import image
shape = mask.shape
connectivity = image.grid_to_graph(n_x=shape[0], n_y=shape[1],
n_z=shape[2], mask=mask)
# Computing the ward for the first time, this is long...
from sklearn.cluster import WardAgglomeration
import time
start = time.time()
ward = WardAgglomeration(n_clusters=500, connectivity=connectivity,
memory='nisl_cache')
ward.fit(epi_masked.T)
print "Ward agglomeration 500 clusters: %.2fs" % (time.time() - start)
# Compute the ward with more clusters, should be faster
start = time.time()
ward = WardAgglomeration(n_clusters=1000, connectivity=connectivity,
memory='nisl_cache')
ward.fit(epi_masked.T)
print "Ward agglomeration 1000 clusters: %.2fs" % (time.time() - start)
### Prepare output ############################################################
### Show result ###############################################################
from matplotlib import pyplot as pl
### Ward ######################################################################
# Compute connectivity matrix: which voxel is connected to which
from sklearn.feature_extraction import image
shape = mask.shape
connectivity = image.grid_to_graph(n_x=shape[0],
n_y=shape[1],
n_z=shape[2],
mask=mask)
# Computing the ward for the first time, this is long...
from sklearn.cluster import WardAgglomeration
import time
start = time.time()
ward = WardAgglomeration(n_clusters=n_clusters,
connectivity=connectivity,
memory='nilearn_cache',
compute_full_tree=True)
ward.fit(fmri_masked)
print "Ward agglomeration %d clusters: %.2fs" % (n_clusters,
time.time() - start)
labels = ward.labels_ + 1
labels = nifti_masker.inverse_transform(labels).get_data()
# 0 is the background, putting it to -1
labels = labels - 1
# Display the labels
plot_labels(labels, 8)
pl.savefig('ward.eps')
pl.savefig('ward.pdf')
"""
Test various n_clusters
"""
for N_CLUSTERS in N_CLUSTERS_SET:
##############################################################################
# Ward
##############################################################################
mask = masker.mask_img_.get_data().astype(np.bool)
shape = mask.shape
connectivity = image.grid_to_graph(n_x=shape[0], n_y=shape[1],
n_z=shape[2], mask=mask)
# Computing the ward for the first time, this is long...
ward = WardAgglomeration(n_clusters=N_CLUSTERS, connectivity=connectivity,
memory='nilearn_cache')
ward.fit(pet_data_masked)
ward_labels_unique = np.unique(ward.labels_)
ward_labels = ward.labels_
##############################################################################
# Generate cluster matrix
##############################################################################
x = np.zeros((len(data), N_CLUSTERS))
for idx in np.arange(len(data)):
for val in ward_labels_unique :
ind = (ward_labels == val)
x[idx, val] = np.mean(pet_data_masked[idx, ind])
masker = NiftiMasker(mask_strategy='epi',
mask_args=dict(opening=8))
masker.fit(pet_files)
pet_masked = masker.transform_niimgs(pet_files, n_jobs=2)
#pet_masked = np.vstack(pet_masked)
mask = masker.mask_img_.get_data().astype(np.bool)
shape = mask.shape
connectivity = image.grid_to_graph(n_x=shape[0], n_y=shape[1],
n_z=shape[2], mask=mask)
# Computing the ward for the first time, this is long...
start = time.time()
ward = WardAgglomeration(n_clusters=1000, connectivity=connectivity,
memory='nilearn_cache')
ward.fit(pet_masked[0])
print "Ward agglomeration 1000 clusters: %.2fs" % (time.time() - start)
labels = ward.labels_ + 1
labels_img = masker.inverse_transform(labels)
first_plot = plot_roi(labels_img, pet_img[0], title="Ward parcellation",
display_mode='xz')
# labels_img is a Nifti1Image object, it can be saved to file with the
# following code:
labels_img.to_filename('parcellation.nii')
"""
##################################################################
# Perform parcellation on smoothed PCA-ed timecourses for each ROI
mem = Memory(cachedir=".", verbose=1)
n_clust = np.zeros(n_rois) # Different #clusters for different ROI
template = np.zeros((dim[0], dim[1], dim[2]))
print ("Performing Ward Clustering")
for i in np.arange(n_rois):
# Determine the number of clusters to divide each ROI into
roi_mask = brain == rois[i]
n_clust[i] = np.round(np.sum(roi_mask) * n_parcels / n_vox)
if n_clust[i] <= 1:
template[roi_mask] = np.shape(np.unique(template))[0]
else:
# Define connectivity based on brain mask
A = grid_to_graph(n_x=dim[0], n_y=dim[1], n_z=dim[2], mask=roi_mask)
# Create ward object
ward = WardAgglomeration(n_clusters=n_clust[i], connectivity=A.tolil(), memory=mem)
ward.fit(tc_group[roi_mask.ravel(), :].T)
template[roi_mask] = ward.labels_ + np.shape(np.unique(template))[0]
# Remove parcels with zero timecourses in any of the subjects
template = template.ravel()
template_refined = template.copy()
label = np.unique(template)
for sub in subList:
print str("Subject" + sub)
# Load preprocessed voxel timecourses
tc = io.loadmat(os.path.join(BASE_DIR, sub, "restfMRI/tc_vox.mat"))
tc = tc["tc"]
# Generate subject-specific tissue mask
gm_file = os.path.join(BASE_DIR, sub, "anat", "gmMask.nii")
if __name__ == '__main__':
memory = Memory('/havoc/cache', mmap_mode='r+')
le = LabelEncoder()
lb = LabelBinarizer()
loader = NiftiMasker(mask='/tmp/mask.nii.gz',
memory=memory, memory_level=1)
reporter = Reporter(report_dir='/tmp/reporter')
cv = ShuffleSplit(len(target), n_iter=5)
Cs = [1e-3, 1e-2, 1e-1, 1., 10, 1e2, 1e3]
scaler = StandardScaler()
n_x, n_y, n_z = mask.shape
connectivity = grid_to_graph(n_x, n_y, n_z, mask=mask_array)
ward = WardAgglomeration(n_clusters=2000,
connectivity=connectivity, memory=memory)
svc = LinearSVC(penalty='l1', dual=False)
# rand_svc = RandomizedWardClassifier(mask_array, n_iter=16,
# memory=memory, n_jobs=-1)
pipe = Pipeline([('scaler', scaler), ('clf', svc)])
grid = GridSearchCV(pipe, param_grid={'clf__C': Cs},
cv=cv, n_jobs=1)
grid.best_estimator_ = grid.estimator
ovr = OneVsRestClassifier(grid, n_jobs=1)
# decoder = Decoder(ovr, loader, lb, reporter)
# decoder.fit(niimgs, target).score(niimgs, target)
# pipeline = Pipeline([('scaler', scaler), ('clf', clf)])
decoder = Decoder(ovr, loader, lb, reporter)
# Perform parcellation on smoothed PCA-ed timecourses for each ROI
mem = Memory(cachedir='.', verbose=1)
n_clust = np.zeros(n_rois) # Different #clusters for different ROI
template = np.zeros((dim[0], dim[1], dim[2]))
print("Performing Ward Clustering")
for i in np.arange(n_rois):
# Determine the number of clusters to divide each ROI into
roi_mask = brain == rois[i]
n_clust[i] = np.round(np.sum(roi_mask) * n_parcels / n_vox)
if n_clust[i] <= 1:
template[roi_mask] = np.shape(np.unique(template))[0]
else:
# Define connectivity based on brain mask
A = grid_to_graph(n_x=dim[0], n_y=dim[1], n_z=dim[2], mask=roi_mask)
# Create ward object
ward = WardAgglomeration(n_clusters=n_clust[i], connectivity=A.tolil(), memory=mem)
ward.fit(tc_group[roi_mask.ravel(), :].T)
template[roi_mask] = ward.labels_ + np.shape(np.unique(template))[0]
# Run relabel_disconnected_parcel.py
# Saving the template
io.savemat(os.path.join(BASE_DIR, "group/ica_roi_parcel150.mat"), {"template":template})
nii = nib.Nifti1Image(template, brain_img.affine)
nib.save(nii, os.path.join(BASE_DIR, "group/ica_roi_parcel150.nii"))
# Remove parcels with zero timecourses in any of the subjects
template = template.ravel()
template_refined = template.copy()
label = np.unique(template)
for sub in subList:
# Spatial smoothing to encourage smooth parcels
dim = np.shape(brain)
tc = tc.reshape((dim[0], dim[1], dim[2], -1))
n_tpts = tc.shape[-1]
for t in np.arange(n_tpts):
tc[:, :, :, t] = gaussian_filter(tc[:, :, :, t], sigma=1)
tc = tc.reshape((-1, n_tpts))
tc = tc[brain.ravel() == 1, :]
# Functional parcellation with Ward clustering
print("Performing Ward Clustering")
mem = Memory(cachedir='.', verbose=1)
# Define connectivity based on brain mask
A = grid_to_graph(n_x=brain.shape[0], n_y=brain.shape[1], n_z=brain.shape[2], mask=brain)
# Create ward object
ward = WardAgglomeration(n_clusters=n_parcels, connectivity=A.tolil(), memory=mem)
ward.fit(tc.T)
template = np.zeros((dim[0], dim[1], dim[2]))
template[brain==1] = ward.labels_ + 1 # labels start from 0, which is used for background
# Remove single voxels not connected to parcel
#for i in np.unique(template)[1:]:
# labels, n_labels = label(template == i, structure=np.ones((3,3,3)))
# if n_labels > 1:
# for j in np.arange(n_labels):
# if np.sum(labels == j + 1) < 10:
# template[labels == j + 1] = 0
# Saving the template
nii = nib.Nifti1Image(template, brain_img.affine)
nib.save(nii, PARCEL_PATH)
elif folding == 'leaveoneout':
n_folds[0] = y.shape[0]
cv = LeaveOneOut(n=y.shape[0])
else:
print("unknown crossvalidation method!")
#-- classifier
clf = svm.SVC(kernel='linear', probability=True, C=svm_C)
#-- normalizer
scaler = Scaler()
#-- Clustering
n_clusters = 100
cluster = WardAgglomeration(n_clusters=n_clusters,
connectivity=None,
compute_full_tree='auto')
#-- feature selection
fs_n = round(n_features * fs_n) / n_features
if fs_n == 100:
fs = SelectKBest(f_classif, k=n_features)
else:
fs = SelectPercentile(f_classif, percentile=fs_n)
#-- results initialization
if compute_predict:
predict = np.zeros([n_splits, n_samples, n_dims, n_dims_tg])**np.nan
predictg = np.zeros([n_splits, n_samplesg, n_dimsg, n_dimsg_tg,
n_folds])**np.nan
else:
pl.axis('off')
# Compute connectivity matrix: which voxel is connected to which
from sklearn.feature_extraction import image
shape = mask.shape
connectivity = image.grid_to_graph(n_x=shape[0],
n_y=shape[1],
n_z=shape[2],
mask=mask)
for n_clusters in 100, 1000:
# Compute Ward clustering
from sklearn.cluster import WardAgglomeration
ward = WardAgglomeration(n_clusters=n_clusters,
connectivity=connectivity,
memory='nilearn_cache',
compute_full_tree=True)
ward.fit(X)
labels = ward.labels_ + 1
labels = masking.unmask(labels, adhd_mask)
# 0 is the background, putting it to -1
labels = labels - 1
# Display the labels
plot_labels(labels, 8)
pl.savefig(join('clustering', 'ward_%i.eps' % n_clusters))
pl.savefig(join('clustering', 'ward_%i.pdf' % n_clusters))
# Compute Kmeans clustering
from sklearn.cluster import MiniBatchKMeans
def BMA_consensus_cluster_parallel(cfg, remote_path, remote_BOLD_fn, remote_mask_fn, Y, nifti_masker, \
num_vox, K_clus, K_clusters, \
parc, alpha, prop, nbItRFIR, onsets, durations,\
output_sub_parc, rescale=True, averg_bold=False):
'''
Performs all steps for one clustering case (Kclus given, number l of the parcellation given)
remote_path: path on the cluster, where results will be stored
'''
import os
import sys
sys.path.append("/home/pc174679/pyhrf/pyhrf-tree_trunk/script/WIP/Scripts_IRMf_BB/Parcellations/")
sys.path.append("/home/pc174679/pyhrf/pyhrf-tree_trunk/script/WIP/Scripts_IRMf_Adultes_Solv/")
sys.path.append("/home/pc174679/pyhrf/pyhrf-tree_trunk/script/WIP/Scripts_IRMf_Adultes_Solv/Scripts_divers_utiles/Scripts_utiles/")
sys.path.append('/home/pc174679/local/installations/consensus-cluster-0.6')
from Random_parcellations import random_parcellations, subsample_data_on_time
from Divers_parcellations_test import *
from RFIR_evaluation_parcellations import JDE_estim, RFIR_estim, clustering_from_RFIR
from Random_parcellations import hrf_roi_to_vox
from pyhrf.tools._io import remote_copy, remote_mkdir
from nisl import io
#nifti_masker.mask=remote_mask_fn
# Creation of the necessary paths --> do not do here
parc_name = 'Subsampled_data_with_' + str(K_clus) + 'clusters'
parc_name_clus = parc_name + 'rnd_number_' + str(parc+1)
remote_sub = os.sep.join((remote_path, parc_name))
#if not os.path.exists(remote_sub):
#os.path.exists(remote_sub)
#print 'remote_sub:', remote_sub
#os.makedirs(remote_sub)
remote_sub_parc = os.sep.join((remote_sub,parc_name_clus))
#if not os.path.exists(remote_sub_parc):
#os.makedirs(remote_sub_parc)
output_RFIR_parc = os.sep.join((output_sub_parc,'RFIR_estim'))
###################################
## 1st STEP: SUBSAMPLING
print '--- Subsample data ---'
Ysub = subsample_data_on_time(Y, remote_mask_fn, K_clus, alpha, prop, \
nifti_masker, rescale=rescale)
print 'Ysub:', Ysub
print 'remote_sub_prc:', remote_sub_parc
Ysub_name = 'Y_sub_'+ str(K_clus) + 'clusters_' + 'rnd_number_' + str(parc+1) +'.nii'
Ysub_fn = os.sep.join((remote_sub_parc, Ysub_name))
Ysub_masked = nifti_masker.inverse_transform(Ysub).get_data()
write_volume(Ysub_masked, Ysub_fn)
###################################
## 2D STEP: RFIR
print '--- Performs RFIR estimation ---'
remote_RFIR_parc_clus = os.sep.join((remote_sub_parc, 'RFIR_estim'))
#if not os.path.exists(remote_RFIR_parc):os.makedirs(remote_RFIR_parc)
#remote_RFIR_parc_clus = os.sep.join((remote_RFIR_parc, parc_name_clus))
#if not os.path.exists(remote_RFIR_parc_clus):os.makedirs(remote_RFIR_parc_clus)
print ' * output path for RFIR ', remote_RFIR_parc_clus
print ' * RFIR for subsampling nb ', str(parc+1), ' with ', K_clus, ' clusters'
RFIR_estim(nbItRFIR, onsets, durations, Ysub_fn, remote_mask_fn, \
remote_RFIR_parc, avg_bold=averg_bold)
hrf_fn = os.sep.join((remote_RFIR_parc_clus, 'rfir_ehrf.nii'))
#remote_copy([hrf_fn], remote_host,
#remote_user, remote_path)[0]
###################################
## 3D STEP: CLUSTERING FROM RFIR RESULTS
name_hrf = 'rfir_ehrf.nii'
from pyhrf.tools._io import write_volume, read_volume
from pyhrf.tools._io import read_volume, write_volume
import nisl.io as ionisl
from sklearn.feature_extraction import image
from sklearn.cluster import WardAgglomeration
from scipy.spatial.distance import cdist, pdist
hrf_fn = os.sep.join((remote_RFIR_parc_clus,name_hrf))
hrf=read_volume(hrf_fn)[0]
hrf_t_fn = add_suffix(hrf_fn, 'transpose')
#taking only 1st condition to parcellate
write_volume(hrf[:,:,:,:,0], hrf_t_fn)
nifti_masker = ionisl.NiftiMasker(remote_mask_fn)
Nm = nifti_masker.fit(hrf_t_fn)
#features: coeff of the HRF
HRF = Nm.fit_transform(hrf_t_fn)
mask, meta_data = read_volume(remote_mask_fn)
shape = mask.shape
connectivity = image.grid_to_graph(n_x=shape[0], n_y=shape[1],
n_z=shape[2], mask=mask)
#features used for clustering
features = HRF.transpose()
ward = WardAgglomeration(n_clusters=K_clus, connectivity=connectivity,
memory='nisl_cache')
ward.fit(HRF)
labels_tot = ward.labels_+1
#Kelbow, Perc_WSS, all_parc_from_RFIR_fns, all_parc_RFIR = \
#clustering_from_RFIR(K_clusters, remote_RFIR_parc_clus, remote_mask_fn, name_hrf, plots=False)
#labels_tot = all_parc_RFIR[str(Kelbow)]
#to retrieve clustering with as many clusters as determined in K_clusters
#labels_tot = all_parc_RFIR[str(K_clus)]
#Parcellation retrieved: for K=Kelbow
#clusters_RFIR_fn = all_parc_from_RFIR[str(Kelbow)]
#clustering_rfir_fn = os.path.join(remote_RFIR_parc_clus, 'output_clustering_elbow.nii')
#write_volume(read_volume(clusters_RFIR_fn)[0], clustering_rfir_fn, meta_bold)
#labels_tot = nifti_masker.fit_transform([clusters_RFIR_fn])[0]
#labels_tot = read_volume(clusters_RFIR_fn)[0]
#labels_name='labels_' + str(int(K_clus)) + '_' + str(parc+1) + '.pck'
#name_f = os.sep.join((remote_sub_parc, labels_name))
#pickle_labels=open(name_f, 'w')
#cPickle.dump(labels_tot,f)
#pickle_labels.close()
#remote_copy(pickle_labels, remote_user,
#remote_host, output_sub_parc)
#################################
## Prepare consensus clustering
print 'Prepare consensus clustering'
clustcount, totalcount = upd_similarity_matrix(labels_tot)
print 'results:', clustcount
return clustcount.astype(np.bool)
#io.savemat(os.path.join(BASE_DIR, "group/tc_rest_pca_vox.mat"), {"tc_group": tc_group})
# Perform parcellation on PCA-ed timecourses
brain_img = as_volume_img("/volatile/bernardng/templates/spm8/rgrey.nii")
brain = brain_img.get_data()
dim = np.shape(brain)
brain = brain > 0.2 # Generate brain mask
brain = mask_utils.largest_cc(brain)
mem = Memory(cachedir='.', verbose=1)
# Define connectivity based on brain mask
A = grid_to_graph(n_x=brain.shape[0],
n_y=brain.shape[1],
n_z=brain.shape[2],
mask=brain)
# Create ward object
ward = WardAgglomeration(n_clusters=500, connectivity=A, memory=mem)
tc_group = tc_group.reshape((dim[0], dim[1], dim[2], -1))
n_tpts = tc_group.shape[-1]
for t in np.arange(n_tpts):
tc_group[:, :, :, t] = gaussian_filter(tc_group[:, :, :, t], sigma=5)
tc_group = tc_group.reshape((-1, n_tpts))
tc_group = tc_group[brain.ravel() == 1, :]
print("Performing Ward Clustering")
ward.fit(tc_group.T)
template = np.zeros((dim[0], dim[1], dim[2]))
template[brain ==
1] = ward.labels_ + 1 # Previously processed data did not include +1
# Remove parcels with zero timecourses in any of the subjects
template = template.ravel()
template_refined = template.copy()
pl.figure(figsize=(3.8, 4.5))
pl.axes([0, 0, 1, 1])
pl.imshow(colors[np.rot90(cut)], interpolation='nearest')
pl.axis('off')
# Compute connectivity matrix: which voxel is connected to which
from sklearn.feature_extraction import image
shape = mask.shape
connectivity = image.grid_to_graph(n_x=shape[0], n_y=shape[1],
n_z=shape[2], mask=mask)
for n_clusters in 100, 1000:
# Compute Ward clustering
from sklearn.cluster import WardAgglomeration
ward = WardAgglomeration(n_clusters=n_clusters, connectivity=connectivity,
memory='nilearn_cache', compute_full_tree=True)
ward.fit(X)
labels = ward.labels_ + 1
labels = masking.unmask(labels, adhd_mask)
# 0 is the background, putting it to -1
labels = labels - 1
# Display the labels
plot_labels(labels, 8)
pl.savefig(join('clustering', 'ward_%i.eps' % n_clusters))
pl.savefig(join('clustering', 'ward_%i.pdf' % n_clusters))
# Compute Kmeans clustering
from sklearn.cluster import MiniBatchKMeans
# Spatial smoothing to encourage smooth parcels
dim = np.shape(brain)
tc = tc.reshape((dim[0], dim[1], dim[2], -1))
n_tpts = tc.shape[-1]
for t in np.arange(n_tpts):
tc[:, :, :, t] = gaussian_filter(tc[:, :, :, t], sigma=1)
tc = tc.reshape((-1, n_tpts))
tc = tc[brain.ravel() == 1, :]
# Functional parcellation with Ward clustering
print("Performing Ward Clustering")
mem = Memory(cachedir=".", verbose=1)
# Define connectivity based on brain mask
A = grid_to_graph(n_x=brain.shape[0], n_y=brain.shape[1], n_z=brain.shape[2], mask=brain)
# Create ward object
ward = WardAgglomeration(n_clusters=n_parcels, connectivity=A.tolil(), memory=mem)
ward.fit(tc.T)
template = np.zeros((dim[0], dim[1], dim[2]))
template[brain == 1] = ward.labels_ + 1 # labels start from 0, which is used for background
# Remove single voxels not connected to parcel
# for i in np.unique(template)[1:]:
# labels, n_labels = label(template == i, structure=np.ones((3,3,3)))
# if n_labels > 1:
# for j in np.arange(n_labels):
# if np.sum(labels == j + 1) < 10:
# template[labels == j + 1] = 0
# Saving the template
nii = nib.Nifti1Image(template, brain_img.affine)
nib.save(nii, PARCEL_PATH)
if types[ai] == bool:
hemi = (hemi <= 0.).astype(float) - 0.5
hemi = factors[ai] * hemi
X = np.append(X.T, [hemi], axis=0).T
X = np.append(X[:, 3:].T, fmri_masked, axis=0).T
print(X.shape)
# Compute a connectivity matrix (for constraining the clustering)
connectivity = sk_image.grid_to_graph(n_x=mask.shape[0],
n_y=mask.shape[1],
n_z=mask.shape[2],
mask=mask)
# Cluster (#2)
start = time.time()
ward = WardAgglomeration(n_clusters=n_clusters,
connectivity=connectivity,
memory=memory)
ward.fit(X.T)
print("Ward agglomeration %d clusters: %.2fs" %
(n_clusters, time.time() - start))
# Compute an image with one ROI per label, and save to disk
labels = ward.labels_ + 1 # Avoid 0 label - 0 means mask.
labels_img = nifti_masker.inverse_transform(labels)
labels_img.to_filename('parcellation.nii')
# Plot image with len(labels) ROIs, and store
# the cut coordinates to reuse for all plots
# and the figure for plotting all to a common axis
if 1 in plots:
def feature_extractor(imgfile, maskfile, featurefile, maskerfile, wardfile, nclusters=[1000,], selectfile=None, targetfile=None, metafile=None, cachefile=None):
resultdict = {"imgfile":imgfile, "maskfile":maskfile}
# load data
print "--loading data"
nifti_masker = input_data.NiftiMasker(mask=maskfile, memory=cachefile, memory_level=1,
standardize=False)
fmri_masked = nifti_masker.fit_transform(imgfile)
print "--getting mask"
mask = nifti_masker.mask_img_.get_data().astype(np.bool)
# saveit
joblib.dump(nifti_masker, maskerfile)
resultdict["mask"] = mask
resultdict["Xmask"] = fmri_masked
resultdict["maskerfile"] = maskerfile
# get connectivity
print "--getting connectivity"
shape = mask.shape
connectivity = image.grid_to_graph(n_x=shape[0], n_y=shape[1],
n_z=shape[2], mask=mask)
# saveit
resultdict["connectivity"] = connectivity
print "--save main file"
np.savez(featurefile+"_main.npz", **resultdict)
# run ward
y = np.load(targetfile)["ymap"]
meta = np.load(metafile)
train = meta["train"]
test = meta["test"]
ncv = meta['ycv']
# for each cv set
for cvx in range(ncv):
trainidx = train[cvx]
testidx = test[cvx]
resultdict = {}
wardfiles = []
selectfiles = []
print "--Running ward %d"%(cvx, )
for ix, nc in enumerate(nclusters):
ward = WardAgglomeration(n_clusters=nc, connectivity=connectivity, memory=cachefile)
ward.fit(fmri_masked[trainidx])
fmri_reduced_train = ward.transform(fmri_masked[trainidx])
fmri_reduced_test = ward.transform(fmri_masked[testidx])
# saveit
subwardfile = wardfile+"_D%d_cv%d.pkl"%(nc, cvx,)
joblib.dump(ward, subwardfile)
resultdict["Xward_%d_train"%(nc,)] = fmri_reduced_train
resultdict["Xward_%d_test"%(nc,)] = fmri_reduced_test
wardfiles.append(subwardfile)
# additional feature selection
selector = SelectPercentile(f_classif, percentile=30)
selector.fit(fmri_reduced_train, y[trainidx])
fmri_select_train = selector.transform(fmri_reduced_train)
fmri_select_test = selector.transform(fmri_reduced_test)
# saveit
subselectfile = selectfile+"_D%d_cv%d.pkl"%(nc, cvx,)
joblib.dump(selector, subselectfile)
resultdict["Xselect_%d_train"%(nc,)] = fmri_select_train
resultdict["Xselect_%d_test"%(nc,)] = fmri_select_test
selectfiles.append(subselectfile)
resultdict["wardfiles"] = wardfiles
resultdict["selectfiles"] = selectfiles
# save results
print "--save cv result"
np.savez(featurefile+"_cv%d.npz"%(cvx, ), **resultdict)
### Mask ###################################################################### fmri_data = dataset.func[0] # Compute a brain mask from nisl import masking mask = masking.compute_mask(fmri_data) # Mask data: go from a 4D dataset to a 2D dataset with only the voxels # in the mask fmri_masked = fmri_data[mask] ### Ward ###################################################################### # Compute connectivity matrix: which voxel is connected to which from sklearn.feature_extraction import image shape = mask.shape connectivity = image.grid_to_graph(n_x=shape[0], n_y=shape[1], n_z=shape[2], mask=mask) # Computing the ward for the first time, this is long... from sklearn.cluster import WardAgglomeration import time start = time.time() ward = WardAgglomeration(n_clusters=5000, connectivity=connectivity) # memory='nisl_cache') ward.fit(fmri_masked.T) print "Ward agglomeration 500 clusters: %.2fs" % (time.time() - start)
def boo(subject_idx=0, cut_coords=None, n_components=20, n_clusters=2000, memory='nilearn_cache'):
mem = Memory(cachedir='nilearn_cache')
# ## Load the data ###################################################
print("Fetch the data files from Internet")
haxby_dataset = datasets.fetch_haxby(n_subjects=subject_idx + 1)
print("Second, load the labels")
haxby_labels = np.genfromtxt(haxby_dataset.session_target[0],
skip_header=1, usecols=[0],
dtype=basestring)
# ## Find voxels of interest ##############################################
print("Load the data.")
anat_filename = haxby_dataset.anat[subject_idx]
anat_img = nibabel.load(anat_filename)
fmri_filename = haxby_dataset.func[subject_idx]
fmri_raw_img = nibabel.load(fmri_filename)
print("Build a mask based on the activations.")
epi_masker = NiftiMasker(mask_strategy='epi', detrend=True, standardize=True)
epi_masker = mem.cache(epi_masker.fit)(fmri_raw_img)
plot_roi(epi_masker.mask_img_,
bg_img=anat_img,
title='EPI mask',
cut_coords=cut_coords)
print("Normalize the (transformed) data") # zscore per pixel, over examples.
fmri_masked_vectors = epi_masker.transform(fmri_raw_img)
fmri_normed_vectors = mem.cache(stats.mstats.zscore)(fmri_masked_vectors, axis=0)
fmri_normed_img = epi_masker.inverse_transform(fmri_normed_vectors)
print("Smooth the (spatial) data.")
fmri_smooth_img = mem.cache(image.smooth_img)(fmri_normed_img, fwhm=7)
print("Mask the MRI data.")
masked_fmri_vectors = mem.cache(epi_masker.transform)(fmri_smooth_img)
# ## Compute mean values based on condition matrix ##########################################
condition_names = list(np.unique(haxby_labels))
n_conditions = len(condition_names)
n_good_voxels = masked_fmri_vectors.shape[1]
mean_vectors = np.empty((n_conditions, n_good_voxels))
for ci, condition in enumerate(condition_names):
condition_vectors = masked_fmri_vectors[haxby_labels == condition, :]
mean_vectors[ci, :] = condition_vectors.mean(axis=0)
# ## Use similarity across conditions as the 4th dimension ##########################################
n_conds = len(condition_names)
n_compares = n_conds * (n_conds - 1) / 2
p_vectors = np.zeros((n_compares, masked_fmri_vectors.shape[1]))
comparison_text = []
comparison_img = []
idx = 0
for i, cond in enumerate(condition_names):
for j, cond2 in enumerate(condition_names[i+1:]):
print("Computing ttest for %s vs. %s." % (cond, cond2))
_, p_vector = stats.ttest_ind(
masked_fmri_vectors[haxby_labels == cond, :],
masked_fmri_vectors[haxby_labels == cond2, :],
axis=0)
p_vector /= p_vector.max() # normalize
p_vector = -np.log10(p_vector)
p_vector[np.isnan(p_vector)] = 0.
p_vector[p_vector > 10.] = 10.
p_img = epi_masker.inverse_transform(p_vector)
comparison_img.append(p_img)
comparison_text.append('%s vs. %s' % (cond, cond2))
p_vectors[idx, :] = p_vector
idx += 1
#n_comparisons = n_conditions * (n_conditions-1) / 2
#similarity_vectors = np.empty((n_good_voxels, n_comparisons))
#for vi in np.arange(n_good_voxels):
# similarity_vectors[vi, :] = pdist(mean_vectors[:, vi])
# Compute a connectivity matrix (for constraining the clustering)
mask_data = epi_masker.mask_img_.get_data().astype(np.bool)
connectivity = sk_image.grid_to_graph(n_x=mask_data.shape[0], n_y=mask_data.shape[1],
n_z=mask_data.shape[2], mask=mask_data)
# Cluster (#2)
start = time.time()
ward = WardAgglomeration(n_clusters=n_clusters, connectivity=connectivity, memory=memory)
ward.fit(p_vectors)
print("Ward agglomeration %d clusters: %.2fs" % (
n_clusters, time.time() - start))
# Compute an image with one ROI per label, and save to disk
labels = ward.labels_ + 1 # Avoid 0 label - 0 means mask.
labels_img = epi_masker.inverse_transform(labels)
labels_img.to_filename('parcellation.nii')
# Plot image with len(labels) ROIs, and store
# the cut coordinates to reuse for all plots
# and the figure for plotting all to a common axis
first_plot = plot_roi(labels_img, title="Ward parcellation", bg_img=anat_img)
plt.show()
def feature_extractor(imgfile,
maskfile,
featurefile,
maskerfile,
wardfile,
nclusters=[
1000,
],
selectfile=None,
targetfile=None,
metafile=None,
cachefile=None):
resultdict = {"imgfile": imgfile, "maskfile": maskfile}
# load data
print "--loading data"
nifti_masker = input_data.NiftiMasker(mask=maskfile,
memory=cachefile,
memory_level=1,
standardize=False)
fmri_masked = nifti_masker.fit_transform(imgfile)
print "--getting mask"
mask = nifti_masker.mask_img_.get_data().astype(np.bool)
# saveit
joblib.dump(nifti_masker, maskerfile)
resultdict["mask"] = mask
resultdict["Xmask"] = fmri_masked
resultdict["maskerfile"] = maskerfile
# get connectivity
print "--getting connectivity"
shape = mask.shape
connectivity = image.grid_to_graph(n_x=shape[0],
n_y=shape[1],
n_z=shape[2],
mask=mask)
# saveit
resultdict["connectivity"] = connectivity
print "--save main file"
np.savez(featurefile + "_main.npz", **resultdict)
# run ward
y = np.load(targetfile)["ymap"]
meta = np.load(metafile)
train = meta["train"]
test = meta["test"]
ncv = meta['ycv']
# for each cv set
for cvx in range(ncv):
trainidx = train[cvx]
testidx = test[cvx]
resultdict = {}
wardfiles = []
selectfiles = []
print "--Running ward %d" % (cvx, )
for ix, nc in enumerate(nclusters):
ward = WardAgglomeration(n_clusters=nc,
connectivity=connectivity,
memory=cachefile)
ward.fit(fmri_masked[trainidx])
fmri_reduced_train = ward.transform(fmri_masked[trainidx])
fmri_reduced_test = ward.transform(fmri_masked[testidx])
# saveit
subwardfile = wardfile + "_D%d_cv%d.pkl" % (
nc,
cvx,
)
joblib.dump(ward, subwardfile)
resultdict["Xward_%d_train" % (nc, )] = fmri_reduced_train
resultdict["Xward_%d_test" % (nc, )] = fmri_reduced_test
wardfiles.append(subwardfile)
# additional feature selection
selector = SelectPercentile(f_classif, percentile=30)
selector.fit(fmri_reduced_train, y[trainidx])
fmri_select_train = selector.transform(fmri_reduced_train)
fmri_select_test = selector.transform(fmri_reduced_test)
# saveit
subselectfile = selectfile + "_D%d_cv%d.pkl" % (
nc,
cvx,
)
joblib.dump(selector, subselectfile)
resultdict["Xselect_%d_train" % (nc, )] = fmri_select_train
resultdict["Xselect_%d_test" % (nc, )] = fmri_select_test
selectfiles.append(subselectfile)
resultdict["wardfiles"] = wardfiles
resultdict["selectfiles"] = selectfiles
# save results
print "--save cv result"
np.savez(featurefile + "_cv%d.npz" % (cvx, ), **resultdict)
def classify(x, y, classifier='naive_bayes', clustering=True, n_folds=10):
"""
Given the predictors and labels, performs multi-label
classification with the given classifier using n-fold
c.v. Constructs a OvR classifier for multilabel prediction.
Parameters
-----------
x : `numpy.ndarray`
(n_samples x n_features) array of features
y : `numpy.ndarray`
(n_samples x n_labels) array of labels
classifier : str, optional
which classifier model to use. Must be one of 'naive_bayes'| 'decision_tree' | 'logistic_regression'.
Defaults to the original naive_bayes.
clustering : bool, optional
whether to do Ward clustering or not. Uses n_clusters = 10,000. Change global N_CLUSTERS for different
value. Defaults to True.
n_folds : int
the number of fold of cv
Returns
-------
score_per_label, score_per_class : tuple
The results are stored as a tuple of two dicts, with the keywords specifying the metrics.
"""
clf = None
ward = None
lb = preprocessing.LabelBinarizer()
y_new = lb.fit_transform(y)
#specify connectivity for clustering
mask = nb.load('data/MNI152_T1_2mm_brain.nii.gz').get_data().astype('bool')
shape = mask.shape
connectivity = image.grid_to_graph(n_x=shape[0], n_y=shape[1], n_z=shape[2], mask=mask)
ward = WardAgglomeration(n_clusters=N_CLUSTERS, connectivity=connectivity)
# choose and assign appropriate classifier
classifier_dict = { 'naive_bayes' : OneVsRestClassifier(MultinomialNB()),
'logistic_regression' : OneVsRestClassifier(LogisticRegression(penalty='l2')),
'decision_tree' : tree.DecisionTreeClassifier()
}
clf = classifier_dict[classifier]
kf = cross_validation.KFold(len(y_new), n_folds=n_folds)
score_per_class = []
score_per_label = []
for train, test in kf:
x_train = np.ascontiguousarray(x[train])
y_train = np.ascontiguousarray(y_new[train])
x_test = np.ascontiguousarray(x[test])
y_test = np.ascontiguousarray(y_new[test])
if clustering:
ward.fit(x_train)
x_train = ward.transform(x_train)
x_test = ward.transform(x_test)
model = clf.fit(x_train, y_train)
predicted = model.predict(x_test)
predict_prob = model.predict_proba(x_test)
if isinstance(predict_prob, list):
predict_prob = np.array(predict_prob)
cls_scores = utils.score_results(y_test, predicted, predict_prob)
label_scores = utils.label_scores(y_test, predicted, predict_prob)
score_per_class.append(cls_scores)
score_per_label.append(label_scores)
return (score_per_class,score_per_label)
### Ward ######################################################################
# Compute connectivity matrix: which voxel is connected to which
from sklearn.feature_extraction import image
shape = mask.shape
connectivity = image.grid_to_graph(n_x=shape[0],
n_y=shape[1],
n_z=shape[2],
mask=mask)
# Computing the ward for the first time, this is long...
from sklearn.cluster import WardAgglomeration
import time
start = time.time()
ward = WardAgglomeration(n_clusters=1000,
connectivity=connectivity,
memory='nilearn_cache')
ward.fit(fmri_masked)
print("Ward agglomeration 1000 clusters: %.2fs" % (time.time() - start))
# Compute the ward with more clusters, should be faster as we are using
# the caching mechanism
start = time.time()
ward = WardAgglomeration(n_clusters=2000,
connectivity=connectivity,
memory='nilearn_cache')
ward.fit(fmri_masked)
print("Ward agglomeration 2000 clusters: %.2fs" % (time.time() - start))
### Show result ###############################################################
fmri_masked = nifti_masker.fit_transform(dataset.func[0])
mask = nifti_masker.mask_img_.get_data().astype(np.bool)
### Ward ######################################################################
# Compute connectivity matrix: which voxel is connected to which
from sklearn.feature_extraction import image
shape = mask.shape
connectivity = image.grid_to_graph(n_x=shape[0], n_y=shape[1],
n_z=shape[2], mask=mask)
# Computing the ward for the first time, this is long...
from sklearn.cluster import WardAgglomeration
import time
start = time.time()
ward = WardAgglomeration(n_clusters=1000, connectivity=connectivity,
memory='nisl_cache')
ward.fit(fmri_masked)
print "Ward agglomeration 1000 clusters: %.2fs" % (time.time() - start)
# Compute the ward with more clusters, should be faster as we are using
# the caching mechanism
start = time.time()
ward = WardAgglomeration(n_clusters=2000, connectivity=connectivity,
memory='nisl_cache')
ward.fit(fmri_masked)
print "Ward agglomeration 2000 clusters: %.2fs" % (time.time() - start)
### Show result ###############################################################
# Unmask data
# Avoid 0 label
def classify(x, y, classifier='naive_bayes', clustering=True, n_folds=10):
"""
Given the predictors and labels, performs single-class
classification with the given classifier using n-fold
c.v. Constructs a OvO classifier for every pair of terms.
Parameters
-----------
x : `numpy.ndarray`
(n_samples x n_features) array of features
y : `numpy.ndarray`
(1 x n_samples) array of labels
classifier : str, optional
which classifier model to use. Must be one of 'naive_bayes'| 'svm' | 'logistic_regression' | 'ensemble'.
Defaults to the original naive_bayes.
clustering : bool, optional
whether to do Ward clustering or not. Uses n_clusters = 10,000. Change global N_CLUSTERS for different
value. Defaults to True.
n_folds : int
the number of fold of cv
Returns
-------
accuracy : `numpy.ndarray`
The results are stored as a list of confusion matrices for each fold and saved
as a numpy array of arrays, for further analysis.
"""
clf = None
ward = None
le = preprocessing.LabelEncoder()
le.fit(y)
y_new = le.transform(y)
# choose and assign appropriate classifier
classifier_dict = { 'naive_bayes' : MultinomialNB(),
'logistic_regression' : LogisticRegression(penalty='l2'),
'svm' : GridSearchCV(LinearSVC(), [{'C': [1, 10, 100, 1000]}])
}
if classifier == 'ensemble':
clf_nb = classifier_dict['naive_bayes']
clf_svm = classifier_dict['svm']
clf_lr = classifier_dict['logistic_regression']
else:
clf = classifier_dict[classifier]
# perform ward clustering if specified
if clustering:
mask = np.load('data/2mm_brain_mask.npy')
shape = mask.shape
connectivity = image.grid_to_graph(n_x=shape[0], n_y=shape[1], n_z=shape[2], mask=mask)
ward = WardAgglomeration(n_clusters=N_CLUSTERS, connectivity=connectivity)
# actual cross validation
kf = cross_validation.KFold(len(y_new), n_folds=n_folds)
accuracy = []
for train, test in kf:
x_train = x[train]
y_train = y_new[train]
x_test = x[test]
y_test = y_new[test]
if clustering:
ward.fit(x_train)
x_train = ward.transform(x_train)
x_test = ward.transform(x_test)
if classifier != 'ensemble':
predicted = clf.fit(x_train, y_train).predict(x_test)
else:
predicted_nb = clf_nb.fit(x_train, y_train).predict(x_test)
predicted_lr = clf_lr.fit(x_train, y_train).predict(x_test)
predicted_svm = clf_svm.fit(x_train, y_train).predict(x_test)
predicted = predicted_nb + predicted_lr + predicted_svm
predicted = np.array(predicted >= 2, dtype=int)
conf_mat = confusion_matrix(y_test, predicted, labels=[0,1])
accuracy.append(conf_mat)
return accuracy
# loading the mask, and binarise
mask = seed.astype(np.bool)
#
shape = mask.shape
#
print 'compute adjacency matrix...'
# compute the adjacency matrix over the target mask
from sklearn.neighbors import kneighbors_graph
connectivity = kneighbors_graph(connect_use2,7)
print 'connectivity for ward:' ,connectivity
print 'ward clustering...'
# perform a hierarchical clustering considering spatial neighborhood
ward = WardAgglomeration(n_clusters = nb_cluster, connectivity=connectivity)
ward.fit(np.transpose(connect))
labelsf = ward.labels_
# the labels are the final labels of each voxels
# OBSOLETE : DON'T USE
elif option_cluster == 2:
# perform the k-means clustering : the labels for each voxel seed are in table : labelsf
print 'kmeans...'
#
k_means = KMeans(init = 'k-means++', n_clusters = nb_cluster, n_init = 10)
#
k_means.fit(connect)
#
labelsf = k_means.labels_
# USE IT INSTEAD
else:
tc_group = np.hstack((tc_group, preprocessing.standardize(pca.transform(tc.T))))
print("Concatenating subject" + sub + "'s timecourses")
#io.savemat(os.path.join(BASE_DIR, "group/tc_rest_pca_vox.mat"), {"tc_group": tc_group})
# Perform parcellation on PCA-ed timecourses
brain_img = as_volume_img("/volatile/bernardng/templates/spm8/rgrey.nii")
brain = brain_img.get_data()
dim = np.shape(brain)
brain = brain > 0.2 # Generate brain mask
brain = mask_utils.largest_cc(brain)
mem = Memory(cachedir='.', verbose=1)
# Define connectivity based on brain mask
A = grid_to_graph(n_x=brain.shape[0], n_y=brain.shape[1], n_z=brain.shape[2], mask=brain)
# Create ward object
ward = WardAgglomeration(n_clusters=500, connectivity=A, memory=mem)
tc_group = tc_group.reshape((dim[0], dim[1], dim[2], -1))
n_tpts = tc_group.shape[-1]
for t in np.arange(n_tpts):
tc_group[:,:,:,t] = gaussian_filter(tc_group[:,:,:,t], sigma=5)
tc_group = tc_group.reshape((-1, n_tpts))
tc_group = tc_group[brain.ravel()==1, :]
print("Performing Ward Clustering")
ward.fit(tc_group.T)
template = np.zeros((dim[0], dim[1], dim[2]))
template[brain==1] = ward.labels_ + 1 # Previously processed data did not include +1
# Remove parcels with zero timecourses in any of the subjects
template = template.ravel()
template_refined = template.copy()
label = np.unique(template)
y = np.dot(X, coef.ravel())
noise = np.random.randn(y.shape[0])
noise_coef = (linalg.norm(y, 2) / np.exp(snr / 20.)) / linalg.norm(noise, 2)
y += noise_coef * noise # add noise
###############################################################################
# Compute the coefs of a Bayesian Ridge with GridSearch
cv = KFold(len(y), 2) # cross-validation generator for model selection
ridge = BayesianRidge()
cachedir = tempfile.mkdtemp()
mem = Memory(cachedir=cachedir, verbose=1)
# Ward agglomeration followed by BayesianRidge
A = grid_to_graph(n_x=size, n_y=size)
ward = WardAgglomeration(n_clusters=10, connectivity=A, memory=mem,
n_components=1)
clf = Pipeline([('ward', ward), ('ridge', ridge)])
# Select the optimal number of parcels with grid search
clf = GridSearchCV(clf, {'ward__n_clusters': [10, 20, 30]}, n_jobs=1, cv=cv)
clf.fit(X, y) # set the best parameters
coef_ = clf.best_estimator_.steps[-1][1].coef_
coef_ = clf.best_estimator_.steps[0][1].inverse_transform(coef_)
coef_agglomeration_ = coef_.reshape(size, size)
# Anova univariate feature selection followed by BayesianRidge
f_regression = mem.cache(feature_selection.f_regression) # caching function
anova = feature_selection.SelectPercentile(f_regression)
clf = Pipeline([('anova', anova), ('ridge', ridge)])
# Select the optimal percentage of features with grid search
clf = GridSearchCV(clf, {'anova__percentile': [5, 10, 20]}, cv=cv)
clf.fit(X, y) # set the best parameters
def _ward_fit_transform(all_subjects_data, fit_samples_indices, connectivity,
n_parcels, offset_labels):
"""Ward clustering algorithm on a subsample and apply to the whole dataset.
Computes a brain parcellation using Ward's clustering algorithm on some
images, then averages the signal within parcels in order to reduce the
dimension of the images of the whole dataset.
This function is used with Randomized Parcellation Based Inference, so we
need to save the labels to further perform the inverse transformation
operation. The function therefore needs an offset to be applied on the
labels so that they are unique across parcellations.
Parameters
----------
all_subjects_data : array_like, shape=(n_samples, n_voxels)
Masked subject images as an array.
fit_samples_indices : array-like,
Indices of the samples used to compute the parcellation.
connectivity : scipy.sparse.coo_matrix,
Graph representing the spatial structure of the images (i.e. connections
between voxels).
n_parcels : int,
Number of parcels for the parcellations.
offset_labels : int,
Offset for labels numbering.
The purpose is to have different labels in all the parcellations that
can be built by multiple calls to the current function.
Returns
-------
parcelled_data : numpy.ndarray, shape=(n_samples, n_parcels)
Average signal within each parcel for each subject.
labels : np.ndarray, shape=(n_voxels,)
Labels giving the correspondance between voxels and parcels.
"""
# XXX: Delayed import is a mega hack which is unfortunately
# required. In scipy versions < 0.11, this import ends up
# importing matplotlib.pyplot. This sets the matplotlib backend
# which causes our matplotlib backend setting code in
# nilearn/plotting/__init__.py to have no effect. In environment
# without X, e.g. travis-ci, that means the tests will fail with
# the usual "TclError: no display name and no $DISPLAY environment
# variable". Note this is dependent on the order of import,
# whichever comes first has the only shot at setting the
# matplotlib backend.
from sklearn.cluster import WardAgglomeration
# fit part
data_fit = all_subjects_data[fit_samples_indices]
ward = WardAgglomeration(n_clusters=n_parcels, connectivity=connectivity)
ward.fit(data_fit)
# transform part
labels = ward.labels_ + offset_labels # unique labels across parcellations
parcelled_data = ward.transform(all_subjects_data)
return parcelled_data, labels
rois = ["V1"]
masks = [cortex.get_roi_mask("MLfs",
"20121210ML_auto1",
roi=roi)[roi] > 0 for roi in rois]
roimask = reduce(lambda x, y: (x + y), masks)
wardmask = cort_mask - roimask
# Load training, test fMRI data
trndata_roi = np.nan_to_num(data.get_train(masked=roimask)[:numtime])
trndata_ward = np.nan_to_num(data.get_train(masked=wardmask)[:numtime])
connectivity = image.grid_to_graph(n_x=wardmask.shape[0],
n_y=wardmask.shape[1],
n_z=wardmask.shape[2],
mask=wardmask)
ward = WardAgglomeration(n_clusters=numclusters, connectivity=connectivity,
memory='nilearn_cache')
ward.fit(trndata_ward)
labels = ward.labels_
trndata_collapsed = np.array([trndata_ward[:, labels == i].mean(1)
for i in range(numclusters)])
trndata = np.hstack((trndata_roi, trndata_collapsed.T))
valdata = data.get_val(masked=roimask)
from ridge import _RidgeGridCV
ridge = _RidgeGridCV(alpha_min=1., alpha_max=1000., n_grid_points=5,
n_grid_refinements=2, cv=2)
ridge_coefs = ridge.fit(sdeltrnstim, trndata).coef_.T
Uridge, sridge, VridgeT = np.linalg.svd(ridge_coefs, full_matrices=False)
