Re: [R] fit lognorm to cdf data

2017-07-11 Thread peter dalgaard
gt;> To: PIKAL Petr >> Cc: r-help@r-project.org >> Subject: Re: [R] fit lognorm to cdf data >> >> How about >> >> proc <- c(0.9, 0.84, 0.5, 0.16, 0.1) >> size <- c(0.144, 0.172, 0.272, 0.481, 0.583) >> plot(size, proc, xlim=c(0,1), ylim=c

Re: [R] fit lognorm to cdf data

2017-07-10 Thread PIKAL Petr
ject.org; PIKAL Petr ; r-help@r- > project.org > Subject: Re: [R] fit lognorm to cdf data > > * fitdistr? > > * it seems unusual (to me) to fit directly to the data with lognormal... > fitting a > normal to the log of the data seems more in keeping with the assumpti

Re: [R] fit lognorm to cdf data

2017-07-10 Thread PIKAL Petr
Hi Great. I did not think that such combination is posssible. Thanks. Petr > -Original Message- > From: peter dalgaard [mailto:pda...@gmail.com] > Sent: Tuesday, July 11, 2017 1:11 AM > To: PIKAL Petr > Cc: r-help@r-project.org > Subject: Re: [R] fit lognorm to cdf

Re: [R] fit lognorm to cdf data

2017-07-10 Thread peter dalgaard
How about proc <- c(0.9, 0.84, 0.5, 0.16, 0.1) size <- c(0.144, 0.172, 0.272, 0.481, 0.583) plot(size, proc, xlim=c(0,1), ylim=c(0,1)) fit<-nls(proc~plnorm(size, log(xmid), sdlog, lower=FALSE), start=list(xmid=0.2, sdlog=.1)) summary(fit) lines(fitted(fit)~size) -pd > On 10 Jul 2017, at 16:27 ,

Re: [R] fit lognorm to cdf data

2017-07-10 Thread Jeff Newmiller
* fitdistr? * it seems unusual (to me) to fit directly to the data with lognormal... fitting a normal to the log of the data seems more in keeping with the assumptions associated with that distribution. -- Sent from my phone. Please excuse my brevity. On July 10, 2017 7:27:47 AM PDT, PIKAL Pet

[R] fit lognorm to cdf data

2017-07-10 Thread PIKAL Petr
Dear all I am struggling to fit data which form something like CDF by lognorm. Here are my data: proc <- c(0.9, 0.84, 0.5, 0.16, 0.1) size <- c(0.144, 0.172, 0.272, 0.481, 0.583) plot(size, proc, xlim=c(0,1), ylim=c(0,1)) fit<-nls(proc~SSfpl(size, 1, 0, xmid, scal), start=list(xmid=0.2, scal=.1)