Re: Linear regression, error on both vaules x and y

*To*: mathgroup at smc.vnet.net*Subject*: [mg70114] Re: Linear regression, error on both vaules x and y*From*: Ralph Kube <ralph.kube at rwth-aachen.de>*Date*: Wed, 4 Oct 2006 05:59:05 -0400 (EDT)*References*: <efldqq$d9l$1@smc.vnet.net> <efq62a$2ep$1@smc.vnet.net>

Ray Koopman wrote: > Ralph Kube wrote: >> Hi, >> I measured the hall-current of a Ge-semiconductor. The experiment >> yielded data for the current and for the voltage, both with their >> own error. Both measurements are uncorrelated. >> Now both the voltage and the current have individual uncertainties >> due to the method of measurement. >> How can I perform a linear fit of this dataset and incorporate both errors? >> Ralph Kube > > Do you mean the voltage uncertainty varies from measure to measure, > and similarly for the current uncertainty? Are the uncertainties > absolute (i.e., standard deviations) or relative (i.e., coefficients > of variation)? Are they known, or only estimated? > Thank you very much for your answers. I solved the problem by using Sqrt[ sigma_x^2 + sigma_y^2] as my weights. It worked well enough. Ralph Kube