similar to: NIST StRD linear regression

Dear Users! I encountered with some problem in data reading while I challenged R (and me too) in a validation point of view. In this issue, I tried to utilize some reference datasets ( http://www.itl.nist.gov/div898/strd/index.html). And the result departed a bit from my expectations. This dataset dedicated to challenge cancellation and accumulation errors (case SmLs07), that's why this

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello all - As I progress in R I am trying to automate functions I would have normally farmed out to Excel, SPSS or Statistica. Single factor anova is one of them. For example, a dataset from NIST StRD (http://www.itl.nist.gov/div898/strd/anova/AtmWtAg.html) has two groups: 1 2 107.8681568 107.8681079 107.8681465 107.8681344

Hello, I am trying to test the precision of R on datasets from The Statistical Reference Datasets Project http://www.itl.nist.gov/div898/strd/index.html and I don't manage to understand how R is storing its results. For example, I calculate a mean on the michelso dataset (100 values) and find: > m=mean(michel) > m V1 299.8524 > print(m,digits=15) V1 299.8524

Hi, > [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Corey Powell > > Do you know of any references that verify the accuracy of R > for basic statistical calculations and tests. The results of > these studies should indicate that R results are the same as > the results of other statistical packages to a certain number > of decimal places on some benchmark

Hi people, I need to prove the good quality of numerical accuracy of R. Anyone knows a paper or anything else comparing R to other statistical softwares in terms of numerical accuracy. I've made a long search about that but I found nothing. Please help me!! Thanx, Talita Leite ------------------------------------------------- Este e-mail foi enviado pelo Webmail da UFAL IMP:

I?m trying to find datasets that will give me residuals, after applying the lm function, with no normality, non linearity, and heteroscedacity so I can try to exemplify those cases in the linear regression model. Can you give any advice on what datasets would be appropiate? I can?t use the ones in the alr3 package because those have already been seen in class. Thank you very much :-) natorro

Hi all, I am a freshman of R,but I am interested in it! Those days,I am learning pages on NIST,with url http://www.itl.nist.gov/div898/handbook/eda/section3/probplot.htm, I am meeting a problem about probability plot and I don't know how to plot a data set with R. Could somebody tell me the answer,and a example is the best! I will look forward to your answer. Thank you very much.

Hola a todos: Estoy intentado realizar un modelo senoidal de unos datos de radiación solar con el fin de afrontar el relleno de la serie y aplicar la prueba de Thom para verificar su homogeneidad [0]. De momento me encuentro con los siguientes problemas: 1- ¿Existe la prueba de Thom en R? ¿O debo crearme mi propia función? 2- Para la realización del modelo senoidal estoy siguiendo los pasos

Hi All, Is the Levenberg-Marquardt algorithm available in R. This method combines the steepest descent algorithm and Newton's method. Thanks in Advance, Dermot MacSweeney. ************************************************************** Dermot MacSweeney NMRC, Email: dsweeney at nmrc.ucc.ie Lee Maltings, Tel: +353 21 904178 Prospect Row, Fax: +353 21 270271 Cork, WWW:

The function wtd.var(x,w) in Hmisc calculates the weighted variance of x where w are the weights. It appears to me that wtd.var(x,w) = var(x) if all of the weights are equal, but this does not appear to be the case. Can someone point out to me where I am going wrong here? Thanks. Tom La Bone [[alternative HTML version deleted]]

Hello. I'm a new user of R, and I have a question regarding the use of aov and lm-functions. I'm doing a fractional factorial experiment at our production site, and I need to familiarize myself with the analysis before I conduct the experiment. I've been working my way through the examples provided at http://www.itl.nist.gov/div898/handbook/pri/section4/pri472.htm

Hi, I'm interested in experimental design and data analysis on mixtures, like cake recipes where the sum of the components is fixed; e.g. <http://www.itl.nist.gov/div898/handbook/pri/section5/pri54.htm>. I can't believe that R doesn't have facilities to design and analyse such experiments, but I haven't been able to find them (I have looked quite hard!). Can anyone point

Hello all, Would somebody be kind enough to show me how to do a KS test in R for a lognormal distribution with ESTIMATED parameters. The R function ks.test()says "the parameters specified must be prespecified and not estimated from the data" Is there a way to correct this when one uses estimated data? Regards, Kwabena. -------------------------------------------- Kwabena Adusei-Poku

Hi, Can anyone please provide the formula used to compute ACF(nlme). I believe the one that is used in R is of the type mentioned on the website. Please correct me if I am wrong. The normalization of the numerator (Ch) has been done by 'N' where as I would like to do it by 'N-k'. Is there anyway in the present implementation of ACF to normalize it by 'N-k', where

hi! I would like to ask help how to generate numbers from g-and-h distribution. This distribution is like normal distribution but span more of the kurtosis and skewness plane. Has R any package on how to generate them? Any help will be greatly appreciated. Thank you so much! Form, Filame Uyaco --------------------------------- [[alternative HTML version deleted]]

Dear Professor I have read your questions in the website on Doubly non-central F-distribution. I am looking for source code for evaluating this function now. I have matlab code but it's only accurate up to the 4th decimal point. Dataplot is more accurate, but it is not user friendly as you only can evaluate one function at a time. So I would like to know do you have found any R code for

Dear R users, I would appreciate for some advise how to generate a Tukey Mean-Difference Plot with the tmd function part of the lattice library. I have two test results (log transformed) which showing a correlation on a scatterplot. However the correlation line is parallel displaced depending on a clinical condition. I thought to a Tukey Mean Difference Plot would show me the difference

Dear R-Users, How can I use chisq.test() as a goodness of fit test? Reading man-page I?ve some doubts that kind of test is available with this statement. Am I wrong? X2=sum((O-E)^2)/E) O=empirical frequencies E=expected freq. calculated with the model (such as normal distribution) See: http://www.itl.nist.gov/div898/handbook/eda/section3/eda35f.htm for X2 used as a goodness of fit test. Any

Brian Ripley wrote (to somebody asking about "effect sizes"): > ... > Given that, I wonder if you are used to standard terminology. Good point. But I think for many of us there is more behind that. I personally belong to an (apparently fairly large) group of R users who may be enthusiastic, but are statistical laymen due to a lack of formal education in the area. The

Does anyone have code to plot bihistograms in R? See http://www.itl.nist.gov/div898/handbook/eda/section3/bihistog.htm for a description of a bihistogram. -- Hal Varian voice: 510-643-4757 SIMS, 102 South Hall fax: 510-642-5814 University of California hal at sims.berkeley.edu Berkeley, CA 94720-4600 http://www.sims.berkeley.edu/~hal