Re: [R] Fitting a function

2010-05-14 Thread Mario Valle
Have you tried Eureqa? http://ccsl.mae.cornell.edu/eureqa It tries to discover the model from your data. Try it, it is impressive (at least on my data). Ciao! mario On 14-May-10 15:07, Thomas Levine wrote: Actually, ignore my comment about that link. I don't think that link is wh

Re: [R] Fitting a function

2010-05-14 Thread Thomas Levine
Actually, ignore my comment about that link. I don't think that link is what you want to look at either. y~x^2 fits quite well, but you could also write a loop to run lm() on a bunch of different transformations. foo=list(log,sqrt) for (bar in foo) { plot(bar(x),y) } There may be a funct

Re: [R] Fitting a function

2010-05-14 Thread Gabor Grothendieck
It appears that as one proceeds from right to left that it flattens out at 0.021 so lets try this where we have added a bit to 0.021 to avoid log(0) plot(x, log(0.0211 - y)) and plot(1/x, log(0.0211 - y)) Except for the first point the latter plot looks linear so lets try: fm <- nls(y ~ cbind(

Re: [R] Fitting a function

2010-05-14 Thread Thomas Levine
I spoke too soon; that is not linear. I've never used the model-fitting functions, but you may check them out. http://developer.r-project.org/model-fitting-functions.txt Tom 2010/5/14 Thomas Levine : > x<-c(0.5,4,6,8,12) > y<-c(0.021,0.021,0.020,0.018,0.012) > lm(y~x) > > 2010/5/14 Dani Valverde

Re: [R] Fitting a function

2010-05-14 Thread Thomas Levine
x<-c(0.5,4,6,8,12) y<-c(0.021,0.021,0.020,0.018,0.012) lm(y~x) 2010/5/14 Dani Valverde : > Hello, > It is a very naive question, but here it is. I have this values: > > x: 0.5 4 6 8 12 > > y: 0.021 0.021 0.020 0.018 0.012 > > I need to fit a function to them. How can I do it with R? > Thank you so

[R] Fitting a function

2010-05-14 Thread Dani Valverde
Hello, It is a very naive question, but here it is. I have this values: x: 0.5 4 6 8 12 y: 0.021 0.021 0.020 0.018 0.012 I need to fit a function to them. How can I do it with R? Thank you so much! Dani -- Daniel Valverde SaubĂ­ Grup de Biologia Molecular de Llevats Facultat de VeterinĂ ria de