Example #1
0
 def nf_select(nf):
     fselector = mvpa2.FixedNElementTailSelector(np.round(nf),
                                                 tail='upper',
                                                 mode='select',
                                                 sort=False)
     sbfs = mvpa2.SensitivityBasedFeatureSelection(
         mvpa2.OneWayAnova(),
         fselector,
         enable_ca=['sensitivities'],
         auto_train=True)
     if (optimize == 1):
         not_test_ds = ds[ds.chunks != chunk]
         train_ds = not_test_ds[not_test_ds.chunks != val_chunk]
         sbfs.train(train_ds)
         ds2 = sbfs(
             not_test_ds
         )  #optimize nf & include validation set for computing dists
     elif (optimize == 0):
         train_ds = ds[
             ds.chunks !=
             chunk]  #retrain with all data if not optimizing
         sbfs.train(train_ds)
         ds2 = sbfs(
             ds
         )  #pick top features with training & use whole dataset for computing dists
     return ds2
Example #2
0
 def nf_select(nf):
     fselector = mvpa2.FixedNElementTailSelector(np.round(nf),
                                                 tail='upper',
                                                 mode='select',
                                                 sort=False)
     sbfs = mvpa2.SensitivityBasedFeatureSelection(
         mvpa2.OneWayAnova(),
         fselector,
         enable_ca=['sensitivities'],
         auto_train=True)
     if (optimize >= 1):
         not_test_ds = ds[ds.chunks != chunk]
         val_ds = not_test_ds[not_test_ds.chunks == val_chunk]
         train_ds = not_test_ds[not_test_ds.chunks != val_chunk]
         sbfs.train(train_ds)
         train_ds = sbfs(train_ds)
         val_ds = sbfs(val_ds)
         return train_ds, val_ds
     elif (optimize == 0):
         train_ds = ds[ds.chunks != chunk]
         test_ds = ds[ds.chunks == chunk]
         sbfs.train(train_ds)
         train_ds = sbfs(train_ds)
         test_ds = sbfs(test_ds)
         return train_ds, test_ds
            def nf_select(nf):
	    #this function is for selecting the number of voxels (i.e., voxels = features)
	    #probably overkill to wrap twice
                fselector = mvpa2.FixedNElementTailSelector(np.round(nf), tail='upper',mode='select', sort=False)
                sbfs = mvpa2.SensitivityBasedFeatureSelection(mvpa2.OneWayAnova(), fselector, enable_ca=['sensitivities'], auto_train=True)
                if(optimize>=1):
                    not_test_ds = ds[ds.chunks!=chunk]
                    val_ds = not_test_ds[not_test_ds.chunks==val_chunk]
                    train_ds = not_test_ds[not_test_ds.chunks!=val_chunk]
                    sbfs.train(train_ds)
                    train_ds = sbfs(train_ds)
                    val_ds = sbfs(val_ds)
                    return train_ds, val_ds;
                elif(optimize==0):
                    train_ds = ds[ds.chunks!=chunk]
                    test_ds = ds[ds.chunks==chunk]
                    sbfs.train(train_ds)
                    train_ds = sbfs(train_ds)
                    test_ds = sbfs(test_ds)
                    return train_ds, test_ds;
Example #4
0
    # REDUCE TO CLASS LABELS, AND ONLY KEEP CONDITIONS OF INTEREST (KEEP VS SWITCH)
    dataset.targets = [t[0] for t in dataset.targets]
    dataset = dataset[N.array([l in ['k', 's'] for l in dataset.sa.targets],
                              dtype='bool')]
    print '... and only', dataset.shape[
        0], 'cases of interest (Keep vs Switch Language)'
    dataset = M.datasets.miscfx.remove_invariant_features(dataset)
    print 'saving as compressed file', trimmedCache
    pickleFile = gzip.open(trimmedCache, 'wb', 5)
    pickle.dump(dataset, pickleFile)

anovaSelectedSMLR = M.FeatureSelectionClassifier(
    M.PLR(),
    M.SensitivityBasedFeatureSelection(
        M.OneWayAnova(),
        M.FixedNElementTailSelector(500, mode='select', tail='upper')),
)
foldwiseCvedAnovaSelectedSMLR = M.CrossValidation(
    anovaSelectedSMLR,
    M.NFoldPartitioner(),
    enable_ca=['samples_error', 'stats', 'calling_time', 'confusion'])
# run classifier
print 'learning on detrended, normalised, averaged, Keep vs Switch ...', datetime.datetime.now(
)
results = foldwiseCvedAnovaSelectedSMLR(dataset)
print '... done', datetime.datetime.now()
print 'accuracy', N.round(100 - N.mean(results) * 100,
                          1), '%', datetime.datetime.now()

#New lines for out putting the result into a csv file.
precision = N.round(100 - N.mean(results) * 100, 1)