Bookmark and Share

Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down on April 23, and its replacement, is already up and running.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: st: Not Quite Quadratic Regression

From   David Hoaglin <>
Subject   Re: st: Not Quite Quadratic Regression
Date   Sun, 5 Aug 2012 12:11:21 -0400


The Box-Cox approach is likely to be more appropriate for y than for x
here, though it would be interesting to see what transformation
emerges for x.

The data on y (or x) must be positive, and -boxcox- assumes that the
errors have a normal distribution.

The estimated power for the transformation should be used as a
starting point in choosing a power that is familiar and likely to be
interpretable.  For example, 0.28 would lead me to consider the square
root and the logarithm (the limiting case as the exponent goes to 0).

David Hoaglin

> Sounds like a job for Box & Cox... help boxcox
> Kit
*   For searches and help try:

© Copyright 1996–2016 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   Site index