<p><strong>It looks like the community made the right decision.</strong>  Xi'an's answer was purely software-oriented, explaining how to use <code>cusum</code> and an iterator in <code>R</code> to accomplish a calculation efficiently.  That makes it a fine answer--on Stack Overflow.</p>

<p>Generally, when a thread is migrated and we would like to take it back, we can contact the moderators on the destination site and ask them to reject the migration.  But it's hard to conceive of a case where a migration would obviously be wrong: our community consists of thoughtful and experienced people.  Although individuals may have differences of opinion, it is highly unlikely that any glaring mistake would be made.  Most likely the best solution for migration of any question that, in retrospect, appears to have some statistical content, would be to persuade the O.P. to re-post it with a focus on the statistical issue.</p>
