how to use fit in logY ?

Hi Does anybody knows how to use fit in log(Y). I mean I have x and y data, I am plotting it and fitting points by straight line using matlab toolbox. When I take log in Y axis my straight fit line becomes curve line. I want straight line fit not curve fit.

How I can get straight fit line in log y plot?

Any advice appreciated.

Answer 1

[Ced]

A line which is straight in a linear plot will always be curved in a log plot...? If you want it to be straight in a log10 plot, your original fit has to be exponential 10^x.

What you can do is e.g. get a linear fit g(x) to log10(y), and then f(x) = 10.^g(x) will be your actual regression function (which is obviously exponential).

[davit petraasya]

Thanks Ced, for your help.