code: def sample(self, x0, nsteps, nskip=1):
          r
          x = np.zeros(shape=(nsteps + 1,))
          x[0] = x0
          for t in range(nsteps):
              q = x[t]
              for s in range(nskip):
                  q = self.step(q)
              x[t + 1] = q
          return x
docs: r"""generate nsteps sample points