Re: [R] Nonlinear logistic regression fitting

2020-07-29 Thread Duncan Murdoch
rdoch Thanks *From:* Duncan Murdoch *Sent:* Wednesday, July 29, 2020 16:04 *To:* Sebastien Bihorel ; J C Nash ; r-help@r-project.org *Subject:* Re: [R] Nonlinear logistic regression fitting Just a quick note about jargon:  you are using the word "likelih

Re: [R] Nonlinear logistic regression fitting

2020-07-29 Thread Sebastien Bihorel via R-help
+ b*x/(c+x)". Correct? Thanks From: Duncan Murdoch Sent: Wednesday, July 29, 2020 16:04 To: Sebastien Bihorel ; J C Nash ; r-help@r-project.org Subject: Re: [R] Nonlinear logistic regression fitting Just a quick note about jargon: you are using the word &q

Re: [R] Nonlinear logistic regression fitting

2020-07-29 Thread Sebastien Bihorel via R-help
b*x/(c+x) From: Duncan Murdoch Sent: Wednesday, July 29, 2020 16:04 To: Sebastien Bihorel ; J C Nash ; r-help@r-project.org Subject: Re: [R] Nonlinear logistic regression fitting Just a quick note about jargon: you are using the word "likelihood" in

Re: [R] Nonlinear logistic regression fitting

2020-07-29 Thread Duncan Murdoch
mu = ~ p_a, pmu = c(a) ) emax_mod <- gnlm::bnlr( y = df[,2:3], link = 'logit', mu = ~ p_a + p_b*x/(p_c+x), pmu = c(a, b, c) ) int_mod emax_mod From: J C Nash Sent: Tuesday, July 28, 2020 14:16 To: Sebastien Bihorel ; r-help@r-project.org Subject: R

Re: [R] Nonlinear logistic regression fitting

2020-07-29 Thread J C Nash
My earlier posting on this thread was misleading. I thought the OP was trying to fit a sigmoid to data. The problem is about fitting 0,1 responses. The reproducible example cleared this up. Another strong demonstration that a "simple reproducible example" can bring clarity so much more quickly tha

Re: [R] Nonlinear logistic regression fitting

2020-07-29 Thread Sebastien Bihorel via R-help
= df[,2:3], link = 'logit', mu = ~ p_a, pmu = c(a) ) emax_mod <- gnlm::bnlr( y = df[,2:3], link = 'logit', mu = ~ p_a + p_b*x/(p_c+x), pmu = c(a, b, c) ) int_mod emax_mod From: J C Nash Sent: Tuesday, July 28, 2020 14:16 To: Sebast

Re: [R] Nonlinear logistic regression fitting

2020-07-28 Thread J C Nash
There is a large literature on nonlinear logistic models and similar curves. Some of it is referenced in my 2014 book Nonlinear Parameter Optimization Using R Tools, which mentions nlxb(), now part of the nlsr package. If useful, I could put the Bibtex refs for that somewhere. nls() is now getting

Re: [R] Nonlinear logistic regression fitting

2020-07-28 Thread Rasmus Liland
Dear Sebastien, On 2020-07-28 14:13 +, Sebastien Bihorel wrote: | Hi | | I need to fit a logistic regression | model using a saturable | Michaelis-Menten function of my | predictor x. The likelihood could be | expressed as: | | L = intercept + emax * x / (EC50+x) | | Which I guess coul

Re: [R] Nonlinear logistic regression fitting

2020-07-28 Thread Rui Barradas
adas > *Sent:* Tuesday, July 28, 2020 12:42 > *To:* Sebastien Bihorel ; > r-help@r-project.org > *Subject:* Re: [R] Nonlinear logistic regression fitting > Hello, > > glm might not be the right tool for the MM model but nls is meant to fit > non-linear models. > A

Re: [R] Nonlinear logistic regression fitting

2020-07-28 Thread Sebastien Bihorel via R-help
From: Rui Barradas Sent: Tuesday, July 28, 2020 12:42 To: Sebastien Bihorel ; r-help@r-project.org Subject: Re: [R] Nonlinear logistic regression fitting Hello, glm might not be the right tool for the MM model but nls is meant to fit non-linear models. And, after an on-line search, there

Re: [R] Nonlinear logistic regression fitting

2020-07-28 Thread Rui Barradas
Hello, glm might not be the right tool for the MM model but nls is meant to fit non-linear models. And, after an on-line search, there is also package drc, function drm. I will use the data and examples in the links below. (The second gave me right, it uses nls.) #install.packages("drc") l

Re: [R] Nonlinear logistic regression fitting

2020-07-28 Thread Berry, Charles
for search engine FAQ! > > Thank anyways > > > From: Bert Gunter > Sent: Tuesday, July 28, 2020 11:12 > To: Sebastien Bihorel > Cc: r-help@r-project.org > Subject: Re: [R] Nonlinear logistic regression fitting > > Search! > ... for "nonline

Re: [R] Nonlinear logistic regression fitting

2020-07-28 Thread Sebastien Bihorel via R-help
Subject: Re: [R] Nonlinear logistic regression fitting You said: "As far as I know (please, correct me if I am wrong), fitting such a model is to not doable with glm, since the function is not linear." My reply responded to that. AFAIK, opinions on packages are off topic

Re: [R] Nonlinear logistic regression fitting

2020-07-28 Thread Bert Gunter
> *Sent:* Tuesday, July 28, 2020 11:12 > *To:* Sebastien Bihorel > *Cc:* r-help@r-project.org > *Subject:* Re: [R] Nonlinear logistic regression fitting > > Search! > ... for "nonlinear logistic regression" at rseek.org. > > Bert Gunter > > "The trouble

Re: [R] Nonlinear logistic regression fitting

2020-07-28 Thread Sebastien Bihorel via R-help
11:12 To: Sebastien Bihorel Cc: r-help@r-project.org Subject: Re: [R] Nonlinear logistic regression fitting Search! ... for "nonlinear logistic regression" at rseek.org<http://rseek.org>. Bert Gunter "The trouble with having an open mind is that people keep coming along

Re: [R] Nonlinear logistic regression fitting

2020-07-28 Thread Bert Gunter
Search! ... for "nonlinear logistic regression" at rseek.org. Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Tue, Jul 28, 2020 at 7:25 AM Sebastien Bihorel via

[R] Nonlinear logistic regression fitting

2020-07-28 Thread Sebastien Bihorel via R-help
Hi I need to fit a logistic regression model using a saturable Michaelis-Menten function of my predictor x. The likelihood could be expressed as: L = intercept + emax * x / (EC50+x) Which I guess could be expressed as the following R model ~ emax*x/(ec50+x) As far as I know (please, correct