Re: [R] local regression using loess

2009-07-28 Thread Alain Zuur
cindy Guo wrote: Hi, All, I have a dataset with binary response ( 0 and 1) and some numerical covariates. I know I can use logistic regression to fit the data. But I want to consider more locally. So I am wondering how can I fit the data with 'loess' function in R? And what will be the

Re: [R] local regression using loess

2009-07-28 Thread Bert Gunter
Actually, loess is much more than an interpolant. I wouldn't even call it that. It is a local regression technique that comes with all the equipment you get in classical regression. But it is meant for normal-like errors, which is not what you have. -- This is misleading. The local

Re: [R] local regression using loess

2009-07-28 Thread Ryan Hafen
Are X1 and X2 both numeric? You might want to get them on equivalent scales, and also play around with the smoothing parameter. Try something like: fit - locfit(Y ~ lp(X1, X2, nn=___, scale=TRUE), family=binomial) and see what happens for different values of nn (try values between 0 and 1

Re: [R] local regression using loess

2009-07-28 Thread Ryan
Bert Gunter gunter.berton at gene.com writes: Actually, loess is much more than an interpolant. I wouldn't even call it that. It is a local regression technique that comes with all the equipment you get in classical regression. But it is meant for normal-like errors, which is not

Re: [R] local regression using loess

2009-07-28 Thread cindy Guo
Bert, Ryan, Alain, You suggestions are very helpful. Thank you. I learned a lot from the discussion. Cindy On Tue, Jul 28, 2009 at 8:53 AM, Ryan rha...@purdue.edu wrote: Bert Gunter gunter.berton at gene.com writes: Actually, loess is much more than an interpolant. I wouldn't even

Re: [R] local regression using loess

2009-07-27 Thread Bert Gunter
-Original Message- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of cindy Guo Sent: Monday, July 27, 2009 4:06 PM To: r-help@r-project.org Subject: [R] local regression using loess Hi, All, I have a dataset with binary response ( 0 and 1) and some

Re: [R] local regression using loess

2009-07-27 Thread cindy Guo
-boun...@r-project.org] On Behalf Of cindy Guo Sent: Monday, July 27, 2009 4:06 PM To: r-help@r-project.org Subject: [R] local regression using loess Hi, All, I have a dataset with binary response ( 0 and 1) and some numerical covariates. I know I can use logistic regression to fit

Re: [R] local regression using loess

2009-07-27 Thread Ryan
Hi, All, I have a dataset with binary response ( 0 and 1) and some numerical covariates. I know I can use logistic regression to fit the data. But I want to consider more locally. So I am wondering how can I fit the data with 'loess' function in R? And what will be the response:

Re: [R] local regression using loess

2009-07-27 Thread cindy Guo
Hi, Ryan, Thank you for the information. I tried it. But there are some error messages. When I use fit - locfit(Y~X1*X2,family='binomial'), the error message is error lfproc(x, y, weights = weights, cens = cens, base = base, geth = geth, : compparcomp: parameters out of bounds And when I use