Mike Stephenson wrote in message ...
>I curve fit some data to the equation 1/y=a+bx using a set of x, y data. I
>used the 1/y form in the curve fit because I could use a linear least
>squares approach. I treated 1/y as "Y" for the curve fit exercise. If I
>were to use it as y=f(x), the equation is no longer linear.
>
>Now, I need to calculate a correlation coefficient but am uncertain how to
>proceed. The curve is plotted as y vs. x and that is what I want the
>correlation coefficient to represent, because I'm comparing this curve fit
>to another more standard equation and would like to know which fits it
>better.
>
>Any takers?
Will you know which fits better after you have calculated some kind
of correlation coefficient?
Why not just calculate the sum of squares (or RMS) of the differences
between the actual and fitted values for Y's?
Better still. Plot the residuals against x and look at them. This should
show up any systematic deviations.
>
>Mucho appreciated.
>
>Mike
>
--
Alan Miller, Retired Scientist (Statistician)
CSIRO Mathematical & Information Sciences
Alan.Miller -at- vic.cmis.csiro.au
http://www.ozemail.com.au/~milleraj
http://users.bigpond.net.au/amiller/
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