[R] Linear model with one known coordinate

Philipp Pagel p.pagel at wzw.tum.de
Thu Aug 28 12:30:02 CEST 2008

> I have a set of points (measurements) and I used lm() to obtain their linear
> regression model. From the biological background this line must pass through
> a point (100,0). Our dataset is not optimal and it shows a slight deviation
> from that coordinate. How can I add the restraint to the model, to go
> through that point?

You can do that with offset(). There is an example in the manual page
for glm.


Dr. Philipp Pagel
Lehrstuhl für Genomorientierte Bioinformatik
Technische Universität München
Wissenschaftszentrum Weihenstephan
85350 Freising, Germany

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