#ph_labels are the labels
        unique = np.unique(ph_labels)
        num_pca = 6
        reduced_ph_features = np.zeros((features.shape[0], num_pca))
        for i in unique:
            from sklearn.decomposition import PCA
            pca = PCA(num_pca)
            indices = np.where(ph_labels == i)[0]
            reduced_ph_features[indices, :] = pca.fit_transform(features[indices, :])