code: def sample(self, rvec0, nsteps, nskip=1):
          r
          rvec = np.zeros(shape=(nsteps + 1, self.dim))
          rvec[0, :] = rvec0[:]
          for t in range(nsteps):
              q = rvec[t, :]
              for s in range(nskip):
                  q = self.step(q)
              rvec[t + 1, :] = q[:]
          return rvec
docs: r"""generate nsteps sample points