[R] least square fit with non-negativity constraints for absorption spectra fitting

2006-07-14 Thread Xu, Xiuli \(NIH/NHLBI\) [E]
I would really appreciate it if someone can give suggestions on how to do spectra fitting in R using ordinary least square fitting and non-negativity constraints. The lm() function works well for ordinary least square fitting, but how to specify non-negativity constraints? It wouldn't make sense

Re: [R] least square fit with non-negativity constraints for absorption spectra fitting

2006-07-14 Thread Joerg van den Hoff
Xu, Xiuli (NIH/NHLBI) [E] wrote: I would really appreciate it if someone can give suggestions on how to do spectra fitting in R using ordinary least square fitting and non-negativity constraints. The lm() function works well for ordinary least square fitting, but how to specify non-negativity

Re: [R] least square fit with non-negativity constraints for absorption spectra fitting

2006-07-14 Thread Prof Brian Ripley
On Fri, 14 Jul 2006, Joerg van den Hoff wrote: Xu, Xiuli (NIH/NHLBI) [E] wrote: I would really appreciate it if someone can give suggestions on how to do spectra fitting in R using ordinary least square fitting and non-negativity constraints. The lm() function works well for ordinary

Re: [R] least square fit with non-negativity constraints for absorption spectra fitting

2006-07-14 Thread Lu Yuefeng
Were you doing blind deconvolution or the spectrum basis are assummed to be known? As for blind deconvolution, alternatively you might consider alternating least square, non-negative matrix factorization, or independent component analysis + alternating least square as the post-processing. yfl