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# r error singular gradient matrix at initial parameter estimates Burgess, Virginia

asked 5 years ago viewed 16372 times active 4 years ago Blog Stack Overflow Podcast #92 - The Guerilla Guide to Interviewing Linked 4 How to fit an exponential equation of Can anyone help me with suggestions? The problem still stays. > > Gabor Grothendieck wrote: >> >> Sorry, its algorithm="brute-force" >> >> On Tue, Mar 30, 2010 at 10:29 AM, Corrado <[hidden email]> wrote: >> >>> >>> Jobs for R usersStatistical Analyst @ Rostock, Mecklenburg-Vorpommern, GermanyData EngineerData Scientist â€“ Post-Graduate Programme @ Nottingham, EnglandDirector, Real World Informatics & Analytics Data Science @ Northbrook, Illinois, U.S.Junior statistician/demographer for UNICEFHealth

Is it safe for a CR2032 coin cell to be in an oven? Share a link to this question via email, Google+, Twitter, or Facebook. The model can now be rewritten without that thorny additive term as $$\mathbb{E}(Y) - c_0 \approx a \exp(b x).$$ That we can take the log of: \log(\mathbb{E}(Y) - c_0) \approx \log(a) John C Nash at Mar 31, 2010 at 11:26 am ⇧ If you have a perfect fit, you have zero residuals.

Also, if my n is 4, then the nls works perfectly (but thatexcludes all the k5 .... kn).Can anyone help me with suggestions? Please provide reproducible code showing what you are doing. Illegal assignment from List to List Why do units (from physics) behave like numbers?

It is not hard to see that the the set of parameters $(a,br^{-m},0,r,c)$ will give the same value of the function to be minimized. On Tue, Mar 30, 2010 at 7:03 AM, Corrado <[hidden email]> wrote: > I am using nls to fit a non linear function to some data. > > The non linear kn).Can anyone help me with suggestions? Also, if my n is 4, then the nls works perfectly (but that excludes all the k5 ....

I am sure the problem is with nls, > because the external fitting algorithm perfectly fits it in less than a > second. However I've not been happy with this choice in the code of nls -- it's been there a long time -- and my own codes from 1974 onwards have always handled fit = nls(yeps ~ p1 / (1 + exp(p2 - x)) * exp(p4 * x)) ...nls still produces the same error. kn).Can anyone help me with suggestions?

Does anyone know what am I doing wrong here? Zero residuals -- perfect fits -- arise when one is interested more or less in an interpolating Prof. All Rights Reserved. Am I a victim of age discrimination?

I do not think I have ever said that. I am sure the problem is with nls, >> because the external fitting algorithm perfectly fits it in less than a >> second. The help page specifically states: Warning Do not use nls on artificial "zero-residual" data. It is also partially linear (d) so it should be possible to get method="plinear" to work.

Also, if my n is 4, then the nls works perfectly (but that excludes > all the k5 .... So, no noise==no good for R's nls. Are there any historically significant examples? singular gradientmatrix at initial parameter estimatesI have read all the previous postings and the documentation, but to noavail: the error is there to stay.

Cooking inside a hotel room SN74LS74AN trouble What is execution model for *args in function call? How can I work around that? Browse other questions tagged r self-study exponential or ask your own question. kn).Can anyone help me with suggestions?

DDoS: Why not block originating IP addresses? Fix either a or n. Learn R R jobs Submit a new job (it's free) Browse latest jobs (also free) Contact us Welcome! Cantonale Galleria 2, 6928 Manno, Switzerland | Fax: +41 (91) 610.82.82 > > -- Felix Nensa Luisenstr. 15-17 44787 Bochum Germany mail: [hidden email] mobile: +49 171 958 51 40

kn).Can anyone help me with suggestions? kn). >>>>> >>>>> Can anyone help me with suggestions? I think requiring the $r \in (0,1)$ would do the job. –Macro Jul 14 '11 at 19:02 add a comment| 2 Answers 2 active oldest votes up vote 11 down vote Efficiently find whether a string contains a group of characters (like substring but ignoring order)?

I am sure the problem is with nls,because the external fitting algorithm perfectly fits it in less than asecond. Do primary and secondary coil resistances correspond to number of windings? I do not think I have ever said that. Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] Yes!

Period. If I use the following: y <- c(1.0385, 1.0195, 1.0176, 1.0100, 1.0090, 1.0079, 1.0068, 1.0099, 1.0038) x <- c(3,4,5,6,7,8,9,10,11) data <- data.frame(x,y) f <- function(x,a,b) {a^b^x} (m <- nls(y ~ f(x,a,b), I do not think I have ever said that. There are many ways to follow us - By e-mail: On Facebook: If you are an R blogger yourself you are invited to add your own R content feed to this

I said that an external algorithms fits the model without any problems: with ~ 500,000 data points and 19 paramters (ki in the original equation), it fits the model in less Can you move a levitating target 120 feet in a single action? If you are using bruteforce its not a problem to have it fail on some of the evaluationssince each one is separate. Browse other questions tagged r curve-fitting nls or ask your own question.

Thanks in advance.Alternatively, what do you suggest I should do? singular gradientmatrix at initial parameter estimatesI have read all the previous postings and the documentation, but to noavail: the error is there to stay. Interviewee offered code samples from current employer -- should I accept? See if it solves your problem.Ravi.-----Original Message-----From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of CorradoSent: Wednesday, March 31, 2010 9:13 AMCc: r-help at r-project.orgSubject: Re: [R] Error "singular gradient