def compute_P(self, Sinv):
        t = np.dot(self.W, self.X)
        self.P = self.W - np.dot(np.dot(t, Sinv), t.T)
Hard link file from ``src`` to ``chroot/dst`` with optional label.
dataset/ETHPy150Open statsmodels/statsmodels/statsmodels/sandbox/panel/mixed.py/Unit.compute_P--crossover with--dataset/ETHPy150Open pantsbuild/pex/pex/common.py/Chroot.link