Ejemplo n.º 1
0
def test_er_nifti_dataset():
    # setup data sources
    tssrc = os.path.join(pymvpa_dataroot, u"bold.nii.gz")
    evsrc = os.path.join(pymvpa_dataroot, "fslev3.txt")
    masrc = os.path.join(pymvpa_dataroot, "mask.nii.gz")
    evs = FslEV3(evsrc).to_events()
    # load timeseries
    ds_orig = fmri_dataset(tssrc)
    # segment into events
    ds = eventrelated_dataset(ds_orig, evs, time_attr="time_coords")

    # we ask for boxcars of 9s length, and the tr in the file header says 2.5s
    # hence we should get round(9.0/2.4) * np.prod((1,20,40) == 3200 features
    assert_equal(ds.nfeatures, 3200)
    assert_equal(len(ds), len(evs))
    # the voxel indices are reflattened after boxcaring , but still 3D
    assert_equal(ds.fa.voxel_indices.shape, (ds.nfeatures, 3))
    # and they have been broadcasted through all boxcars
    assert_array_equal(ds.fa.voxel_indices[:800], ds.fa.voxel_indices[800:1600])
    # each feature got an event offset value
    assert_array_equal(ds.fa.event_offsetidx, np.repeat([0, 1, 2, 3], 800))
    # check for all event attributes
    assert_true("onset" in ds.sa)
    assert_true("duration" in ds.sa)
    assert_true("features" in ds.sa)
    # check samples
    origsamples = _load_anyimg(tssrc)[0]
    for i, onset in enumerate([value2idx(e["onset"], ds_orig.sa.time_coords, "floor") for e in evs]):
        assert_array_equal(ds.samples[i], origsamples[onset : onset + 4].ravel())
        assert_array_equal(ds.sa.time_indices[i], np.arange(onset, onset + 4))
        assert_array_equal(ds.sa.time_coords[i], np.arange(onset, onset + 4) * 2.5)
        for evattr in [a for a in ds.sa if a.count("event_attrs") and not a.count("event_attrs_event")]:
            assert_array_equal(evs[i]["_".join(evattr.split("_")[2:])], ds.sa[evattr].value[i])
    # check offset: only the last one exactly matches the tr
    assert_array_equal(ds.sa.orig_offset, [1, 1, 0])

    # map back into voxel space, should ignore addtional features
    nim = map2nifti(ds)
    # origsamples has t,x,y,z
    assert_equal(nim.get_shape(), origsamples.shape[1:] + (len(ds) * 4,))
    # check shape of a single sample
    nim = map2nifti(ds, ds.samples[0])
    # pynifti image has [t,]z,y,x
    assert_equal(nim.get_shape(), (40, 20, 1, 4))

    # and now with masking
    ds = fmri_dataset(tssrc, mask=masrc)
    ds = eventrelated_dataset(ds, evs, time_attr="time_coords")
    nnonzero = len(_load_anyimg(masrc)[0].nonzero()[0])
    assert_equal(nnonzero, 530)
    # we ask for boxcars of 9s length, and the tr in the file header says 2.5s
    # hence we should get round(9.0/2.4) * np.prod((1,20,40) == 3200 features
    assert_equal(ds.nfeatures, 4 * 530)
    assert_equal(len(ds), len(evs))
    # and they have been broadcasted through all boxcars
    assert_array_equal(ds.fa.voxel_indices[:nnonzero], ds.fa.voxel_indices[nnonzero : 2 * nnonzero])
Ejemplo n.º 2
0
def test_er_nifti_dataset():
    # setup data sources
    tssrc = os.path.join(pymvpa_dataroot, u'bold.nii.gz')
    evsrc = os.path.join(pymvpa_dataroot, 'fslev3.txt')
    masrc = os.path.join(pymvpa_dataroot, 'mask.nii.gz')
    evs = FslEV3(evsrc).to_events()
    # load timeseries
    ds_orig = fmri_dataset(tssrc)
    # segment into events
    ds = eventrelated_dataset(ds_orig, evs, time_attr='time_coords')

    # we ask for boxcars of 9s length, and the tr in the file header says 2.5s
    # hence we should get round(9.0/2.4) * np.prod((1,20,40) == 3200 features
    assert_equal(ds.nfeatures, 3200)
    assert_equal(len(ds), len(evs))
    # the voxel indices are reflattened after boxcaring , but still 3D
    assert_equal(ds.fa.voxel_indices.shape, (ds.nfeatures, 3))
    # and they have been broadcasted through all boxcars
    assert_array_equal(ds.fa.voxel_indices[:800],
                       ds.fa.voxel_indices[800:1600])
    # each feature got an event offset value
    assert_array_equal(ds.fa.event_offsetidx, np.repeat([0, 1, 2, 3], 800))
    # check for all event attributes
    assert_true('onset' in ds.sa)
    assert_true('duration' in ds.sa)
    assert_true('features' in ds.sa)
    # check samples
    origsamples = _load_anyimg(tssrc)[0]
    for i, onset in \
        enumerate([value2idx(e['onset'], ds_orig.sa.time_coords, 'floor')
                        for e in evs]):
        assert_array_equal(ds.samples[i], origsamples[onset:onset + 4].ravel())
        assert_array_equal(ds.sa.time_indices[i], np.arange(onset, onset + 4))
        assert_array_equal(ds.sa.time_coords[i],
                           np.arange(onset, onset + 4) * 2.5)
        for evattr in [
                a for a in ds.sa
                if a.count("event_attrs") and not a.count('event_attrs_event')
        ]:
            assert_array_equal(evs[i]['_'.join(evattr.split('_')[2:])],
                               ds.sa[evattr].value[i])
    # check offset: only the last one exactly matches the tr
    assert_array_equal(ds.sa.orig_offset, [1, 1, 0])

    # map back into voxel space, should ignore addtional features
    nim = map2nifti(ds)
    # origsamples has t,x,y,z
    if externals.versions['nibabel'] >= '1.2':
        vol_shape = nim.shape
    else:
        vol_shape = nim.get_shape()
    assert_equal(vol_shape, origsamples.shape[1:] + (len(ds) * 4, ))
    # check shape of a single sample
    nim = map2nifti(ds, ds.samples[0])
    if externals.versions['nibabel'] >= '1.2':
        vol_shape = nim.shape
    else:
        vol_shape = nim.get_shape()
    # pynifti image has [t,]z,y,x
    assert_equal(vol_shape, (40, 20, 1, 4))

    # and now with masking
    ds = fmri_dataset(tssrc, mask=masrc)
    ds = eventrelated_dataset(ds, evs, time_attr='time_coords')
    nnonzero = len(_load_anyimg(masrc)[0].nonzero()[0])
    assert_equal(nnonzero, 530)
    # we ask for boxcars of 9s length, and the tr in the file header says 2.5s
    # hence we should get round(9.0/2.4) * np.prod((1,20,40) == 3200 features
    assert_equal(ds.nfeatures, 4 * 530)
    assert_equal(len(ds), len(evs))
    # and they have been broadcasted through all boxcars
    assert_array_equal(ds.fa.voxel_indices[:nnonzero],
                       ds.fa.voxel_indices[nnonzero:2 * nnonzero])