Exemplo n.º 1
0
    data = np.random.randn(n, p)
    I = np.where(np.square(XYZ - XYZ.max(axis=1).reshape(-1, 1) / 2).sum(
            axis=0) <= r ** 2)[0]
    data[:, I] += signal
    vardata = np.random.randn(n, p) ** 2
    if axis == 1:
        data = data.T
        vardata = vardata.T
    return data, vardata, XYZ

###############################################################################
# Example for using permutation_test_onesample class
data, vardata, XYZ = make_data()

# rfx calibration
P = PT.permutation_test_onesample(data, XYZ)

# clusters definition (height threshold, max diameter)
c = [(P.random_Tvalues[P.ndraws * (0.95)], None)]

# regions definition (label vector)
r = np.ones(data.shape[1], int)
r[data.shape[1]/2.:] *= 10
voxel_results, cluster_results, region_results = \
                P.calibrate(nperms=100, clusters=c, regions=[r])

# mfx calibration
P = PT.permutation_test_onesample(data, XYZ, vardata=vardata,
                                  stat_id="student_mfx")
voxel_results, cluster_results, region_results = \
                P.calibrate(nperms=100, clusters=c, regions=[r])
Exemplo n.º 2
0
import numpy as np

from nipy.labs.group.permutation_test import permutation_test_onesample

from nipy.utils import example_data

# Get group data
group_data = example_data.get_filename('neurospin', 'language_babies',
                                       'offset_002.npz')

f = np.load(group_data)
data, vardata, xyz = f['mat'], f['var'], f['xyz']

# Create one-sample permutation test instance
ptest = permutation_test_onesample(data, xyz, stat_id='wilcoxon')

# Cluster definition: (threshold, diameter)
# Note that a list of definitions can be passed to ptest.calibrate
cluster_def = (ptest.height_threshold(0.01), None)
print cluster_def

# Multiple calibration
# To get accurate pvalues, don't pass nperms (default is 1e4)
# Yet it will take longer to run
voxel_res, cluster_res, region_res = ptest.calibrate(nperms=100,
                                                     clusters=[cluster_def])

# Simulated Zmax values for FWER correction
simu_zmax = ptest.zscore(voxel_res['perm_maxT_values'])