                    sj.append(0)
            silist.append(si)
            sjlist.append(sj)
        if spad is not None:
            return (pad_sequences(silist, maxlen=spad, truncating='post', padding='post'),
                    pad_sequences(sjlist, maxlen=spad, truncating='post', padding='post'))
        else:
            return (silist, sjlist)

    def embmatrix(self, emb):