<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def mean_sq_jump_dist(self, discard_frac=0.1):
 """Mean squared jumping distance estimated from chain. Parameters discard_frac: float fraction of iterations to discard at the beginning (as a burn-in) Returns ------- float """

        discard = int(self.niter * discard_frac)
        return msjd(self.chain.theta[discard:])