def test_pcamapper(): # data: 40 sample feature line in 20d space (40x20; samples x features) ndlin = Dataset(np.concatenate([np.arange(40) for i in range(20)]).reshape(20,-1).T) pm = PCAMapper() # train PCA assert_raises(mdp.NodeException, pm.train, ndlin) ndlin.samples = ndlin.samples.astype('float') ndlin_noise = ndlin.copy() ndlin_noise.samples += np.random.random(size=ndlin.samples.shape) # we have no variance for more than one PCA component, hence just one # actual non-zero eigenvalue assert_raises(mdp.NodeException, pm.train, ndlin) pm.train(ndlin_noise) assert_equal(pm.proj.shape, (20, 20)) # now project data into PCA space p = pm.forward(ndlin.samples) assert_equal(p.shape, (40, 20)) # check that the mapped data can be fully recovered by 'reverse()' assert_array_almost_equal(pm.reverse(p), ndlin)
def test_pcamapper(): # data: 40 sample feature line in 20d space (40x20; samples x features) ndlin = Dataset( np.concatenate([np.arange(40) for i in range(20)]).reshape(20, -1).T) pm = PCAMapper() # train PCA assert_raises(mdp.NodeException, pm.train, ndlin) ndlin.samples = ndlin.samples.astype('float') ndlin_noise = ndlin.copy() ndlin_noise.samples += np.random.random(size=ndlin.samples.shape) # we have no variance for more than one PCA component, hence just one # actual non-zero eigenvalue assert_raises(mdp.NodeException, pm.train, ndlin) pm.train(ndlin_noise) assert_equal(pm.proj.shape, (20, 20)) # now project data into PCA space p = pm.forward(ndlin.samples) assert_equal(p.shape, (40, 20)) # check that the mapped data can be fully recovered by 'reverse()' assert_array_almost_equal(pm.reverse(p), ndlin)