Pavlos, There are several ways to evaluate how well new data fit an old regression.Part of the answer depends on what you are concerned about. For example, if you are concerned about bias, you can test whether the mean of the new data is within the expected range of the mean of that many new values. The equations for these prediction intervals should be in good texts on linear regression. Dave
Date: Sun, 27 Oct 2013 13:36:12 +0200 From: Pavlos Pavlidis <pavlid...@gmail.com> To: r-help <r-help@r-project.org> Subject: Re: [R] how well *new data* fit a pre-computed model Message-ID: <CABZ9MBUEuCVbF0WKRFuBtbWYKwjYzvvJmusmrypTFPa+yB=q...@mail.gmail.com> Content-Type: text/plain Here is a link to a plot that illustrates the question: bio.lmu.de/~pavlidis/pg1.pdf the question is how to evaluate whether the blue points fit the curve well enough. The curve has been produced from the black points best pavlos On Sun, Oct 27, 2013 at 1:30 PM, Pavlos Pavlidis <pavlid...@gmail.com>wrote: > Hi all, > I have fitted polynomial models to a bunch of data (time-course analysis). > The experiment is "the expression value of gene A under condition K over > time". The data points that have been used to fit the model are about 200 > (dataset A). Furthermore I have a few data (dataset B; about 10 points) for > "the expression values of gene A under condition G over time". The question > is: > > how can I evaluate how well the dataset B fits the model generated by > dataset A? > > kind regards, > pavlos > > -- > > Pavlos Pavlidis, PhD > > Foundation for Research and Technology - Hellas > Institute of Molecular Biology and Biotechnology > Íikolaou Plastira 100, Vassilika Vouton > GR - 711 10, Heraklion, Crete, Greece > -- Pavlos Pavlidis, PhD Foundation for Research and Technology - Hellas Institute of Molecular Biology and Biotechnology Íikolaou Plastira 100, Vassilika Vouton GR - 711 10, Heraklion, Crete, Greece [[alternative HTML version deleted]] ------------------------------ [[alternative HTML version deleted]]
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