stats toolbox...fitting a curve to a plot in log log space

Hi,

I'm trying to fit a curve to a log-log plot, but the dfittool will not let me change the axes to log. I can do log plots, but then can't put them into the dfittool. Do I need to write something for this? How would I do that? Please help!

Thank you!

Answer 1

[Richard Willey]

Question and a Comment

First, the question: It's unclear whether you are trying to do a curve fit or a distribution fit. You're talking about a curve fitting problem, however, the tool that you are using (dfittool) is intended for fitting distributions.

Next the comment: Statistics Toolbox has a nice demo titled "Pitfalls in Fitting Nonlinear Models by Transforming to Linearity"

http://www.mathworks.com/products/statistics/demos.html?file=/products/demos/shipping/stats/xform2lineardemo.html

The demo includes a lot of good example code dealing with displaying data on a log scale

Answer 2

[cassie browne]

Ah, I'm trying to do a distribution fit. I have a data set and I need to find a function that fits the data, and how close the data are to the function. But I have a curve defining my distribution in log log space (that's just how we discuss these issues in my area of research).