def _get_YYTfactor(self, Y):
N, D = Y.shape<EOL>if (N>=D):<EOL><INDENT>return Y.view(np.ndarray)<EOL><DEDENT>else:<EOL><INDENT>return jitchol(tdot(Y))<EOL><DEDENT>
find a matrix L which satisfies LLT = YYT.

Note that L may have fewer columns than Y.