similar to: "F-value" and "P-value" for nonlinear regression ...

Dear colleagues, I have used statistical software "R" in academic research, and I find very interesting. So now I have started my studies at advanced level. I have conducted several statistical models of the type "*nls*". In respect of procedures for models of the type nls, I'd like you answer only one question that I have had doubts, related to the formula

Dear all, I would like to know whether any specification test for linear against nonlinear model hypothesis has been implemented in R using the quantreg package. I could read papers concerning this issue, but they haven't been implemented at R. As far as I know, we only have two specification tests in this line: anova.rq and Khmaladze.test. The first one test equality and significance of

Hello, If I understand good, I can't have p-value for the nls model. I have 2 vectors. And I'am doing model <- nls(crf ~a*(1-exp(-x/b)) + c, data= d, start = list(a=1, b=3, c=0)) and I want to know If my result is significat, if I can't have p-value, how can I know it? Thank you

I am using nonlinear regression to fit a couple of variables to a set of measurements. I would like to do some significance tests for the estimated parameters. I am able to check the confidence intervals using the Jacobian coming out of nonlinear regression. I do see in a paper which shows t-value (it says estimated by White method??), f-value, f-test, and j-test, are these available in matlab,

Dear colleagues, Von Bertalanffy model is commonly adjust to data on fish length (TL) and age (AGE) TL= Linf*(1-exp(-K*(AGE-t0)). Linf, K and t0 are parameters of the model. One main goal of the growth study is the comparison of growth parameter estimates between sexes of the same species, or estimates from different populations. The realibility statistical tests normally applied are highly

I have application that i send email normal with native ruby. But when i execute the sample application with jruby, it dont send email and dont get error. What can be wrong? -- Atenciosamente, Paulo Coutinho. Blog: www.prsolucoes.com/blog Site: www.prsolucoes.com Msn: paulo-QE/7f1ia5mR0ubjbjo6WXg@public.gmane.org -- You received this message because you are subscribed to the Google Groups

Dear All, I installed R with the commands sudo apt-get update sudo apt-get install r-base sudo apt-get install r-base-dev But when I try install.packages() to install the package rimage it does not work. Please let me know what should I do? Ys, Getulio

Hi. I have some apps that i have "admin" areas to the clients manager the app. This "admin" is a directory on my controllers path, like this: my_site --> app -->-->controllers -->-->-->admin And my controllers in "admin", i use the correct namespace(example for clients_controller): class Admin::ClientsController < AdminController Only doing

Hey, I've been strugling to get quota working on my enviroment. I have one storage server that exports the 'home' dir. My mail server mounts the exported 'home' server at '/home' # dovecot --version > 1.1.14 I'm also running Postfix and using Dovecot/LDA as MDA so that we can use the Dovecot's Quota plugin. The thing is that if the user has exceeded

Dear R users, I am analyzing several response variables (all scaled to [0;1]) using a multivariate linear model. After fitting the model, I set up a hypothesis matrix to test specific contrasts for these response variables; for example: "a always increases significantly more than b when regressed against x". What I am stuck with now is how to calculate the correct F-values (and

Do Users of Nonlinear Mixed Effects Models Know Whether Their Software Really Works? Lesaffre et. al. (Appl. Statist. (2001) 50, Part3, pp 325-335) analyzed some simple clinical trials data using a logistic random effects model. Several packages and methods MIXOR, SAS NLMIXED were employed. They reported obtaining very different parameter estimates and P

Hi, I have been brought back to the "R-Side" from MatLab. I have used R in graduate econometrics but only for statistics and regression (linear and nonlinear). But now I need to run general nonlinear optimization. I know about the add-in quadprog but my problem is not QP. My problem is a general nonlinear (obj funct) with linear constraints.I know about the "ms" and

I believe the binom.test procedure is producing one tailed p values rather than the two tailed value implied by the alternative hypothesis language. A textbook and SAS both show 2*9.94e-07 = 1.988e-06 as the two tailed value. As does the R summation syntax from R below. It looks to me like the alternative hypothesis language should be revised to something like " ... greater than or equal

Hi, i am doing a statistics course and am having trouble with an exercise where i need to determine whether my success rate at something is higher than 80%. I was successful in 29 out of 60 trials, so these were the commands i entered into R: >n=60 >p.hat=29/n >p.0=0.8 >se.0=sqrt(p.0*(1-p.0)/n) >z=(p.hat-p.0)/se.0 >print(z) Which returned: [1] -6.132224 >1-pnorm(z) Which

Dear R-Help, I am trying to use R to solve a nonlinear equation many times for different values. I am looking for a mathematical nonlinear equation solution which may not have a closed solution form. For example, I have equation: 2 = (t^2)/log(t) What is t? I am wondering how to solve it in R. Many thanks, Zhu Wang Statistical Science Department SMU.

Dear all, I'm interested in testing 2 nonlinear restrictions on coefficients of a nls object. Is there a package for doing this? Something in the lines of `test(nls object, res=c("res 1","res 2"),...)' I only found the function delta.method in the alr3 library that calculates the se of a singleton nonlinear restriction of a nls object using the delta method. Thanks in

Hi All, Could any one tells me if R or S has the capacity to fit nonlinear regression with Huber's M estimation? Any suggestion is appreciated. I was aware of 'rlm' in MASS library for robust linear regression and 'nls' for nonlinear least squares regression, but did not seem to be able to find robust non-linear regression function. Thanks and regards, Ray Liu

Hello, I'm having trouble figuring out how to calculate a p-value for a 1-tailed test of beta_1 in a linear model fit using command lm. My model has only 1 continuous, predictor variable. I want to test the null hypothesis beta_1 is >= 0. I can calculate the p-value for a 2-tailed test using the code "2*pt(-abs(t-value), df=degrees.freedom)", where t-value and degrees.freedom

Hello, I?m with a problem in using nonlinear quantile regression, the function nlrq. I want to do a quantile regression o nonlinear function in the form a*log(x)-b, the coefficients ?a? and ?b? is my objective. I try to use the command: funx <- function(x,a,b){ res <- a*log(x)-b res } Dat.nlrq <- nlrq(y ~ funx(x, a, b), data=Dat, tau=0.25, trace=TRUE) But a can?t solve de problem,

Dear all, I just know how to solve an eaquation by using optim() or nlm(). But, now, I have three nonlinear equations, how could we use optim() or nlm() to solve  a system of nonlinear equations in R?  Thank you so much. Sincerely, Joe ___________________________________________________ 您的生活即時通 － 溝通、娛樂、生活、工作一次搞定！ [[alternative HTML version deleted]]