Can anyone comment on the use of double mass analysis, a commonly recommended technigue in hydrology texts use to detect a change in the assumed linear relation between two variables? The method involves plotting the cumulative values (in time order) of the two variables against one another and looking for a change in slope. I've not seen the method discussed in any statistics literature or books on graphical techniques and wondered if that is because it is not as useful as other approaches or has some major drawbacks. I don't know of any proposals, for example, for objectively establishing the change point and its significance. Jack Lewis [EMAIL PROTECTED] Sent via Deja.com http://www.deja.com/ Before you buy. =========================================================================== This list is open to everyone. Occasionally, less thoughtful people send inappropriate messages. Please DO NOT COMPLAIN TO THE POSTMASTER about these messages because the postmaster has no way of controlling them, and excessive complaints will result in termination of the list. For information about this list, including information about the problem of inappropriate messages and information about how to unsubscribe, please see the web page at http://jse.stat.ncsu.edu/ ===========================================================================
