V_r2 not in ODR fit?

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Mon, 04/15/2013 - 04:39 am

Hi,

I am using ODR fitting on linear data with a positive correlation. I run:
CurveFit/ODR=2 line, Ydata/X=Xdata/D

Why does this not give a measure of r or r2 in the text readout, as you would get for CurveFit line, Ydata/X=Xdata/D ?

Is there any way to access r or r2 values from the ODR calculation?

Thanks!
Emma also sent a query to support@wavemetrics.com.

For the benefit of others who might read this, my understanding of the situation is that ODR fitting is fundamentally nonlinear and these measures of correlation are not appropriately applied to a nonlinear function. This is true even when fitting a line- the orthogonal distance measure introduces a nonlinearity that is not present when doing a standard least squares fit to a line.

John Weeks
WaveMetrics, Inc.
support@wavemetrics.com

April 15, 2013 at 09:53 am - Permalink