similar to: References verifying accuracy of R for basic statisticalcalculations and tests

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

NIST maintains a repository of Statistical Reference Datasets at http://www.itl.nist.gov/div898/strd/. I have been working through the datasets to compare R's results to their references with the hope that if all works well, this could become a validation package. All the linear regression datasets give results with some degree of accuracy except one. The NIST model includes 11 parameters,

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

Dear R-Helpers, I have a matrix where the first column is known. The second column is the result of multiplying this first column with a constant "const". The third column is the result of multiplying the second column with "const"..... So far, I did it like this (as a simplified example): nr.of.columns <- 4 myconstant <- 27.5 mymatrix <- matrix(numeric(0), nrow=5,

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

Dear All, I have these data: exampledata <- c("This is one item", "This is Another One", "And so is This") I would like to find each occurence of a blank space followed by a Capital Letter and replace it by a blank space, a left curly brace, the respective Capital Letter, and then a right curly brace. I thought the following will do: gsub(pattern = "

Dear R-Users, given you have been teaching R to students (grad level, mainly social science background, no previous programming experience, 80% know SPSS), what are your experiences concerning the style of teaching? Do you prefer to stand in front of the class like in "normal" lectures and you show them slides? Or do you you explain some concept (for example things like

Dear all, I have a population with three age-classes, at time t=0 the population is: n.zero <- c(1,0,0) I have a transition matrix A which denotes "fertility" and "survival": A <- matrix(c(0,1,5, 0.3,0,0, 0,0.5,0), ncol=3, byrow=TRUE) To obtain the population at t=1, I calculate: A %*% n.zero To obtain the population t=2, I calculate: A %*% (A %*% n.zero) ... and so

Dear all, I wanted to make a two-way-table of two variables with a counting variable stored in another column of a dataframe. In version 1.9.1, the behavior is as expected as shown in the simplified example code. > sex <- rep(c("F", "M"), 5) > income <- c(rep("low", 5), rep("high", 5)) > count <- 1:10 > mydf <-

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.

Dear all, given I have data in a data.frame which indicate the number of people in a specific year at a specific age: n <- 10 mydf <- data.frame(yr=sample(1:10, size=n, replace=FALSE), age=sample(1:12, size=n, replace=FALSE), no=sample(1:10, size=n, replace=FALSE)) Now I would like to make a matrix with (in this simple example) 10 columns (for the

Dear all, This is a rather lengthy message, but I don't know what I made wrong in my real example since the simple code works. I have two variables a, b and a function f for which I would like to calculate all possible combinations of the values of a and b. If f is multiplication, I would simply do: a <- 1:5 b <- 1:5 outer(a,b) ## A bit more complicated is this: f <-

Dear all, This is a rather lengthy message, but I don't know what I made wrong in my real example since the simple code works. I have two variables a, b and a function f for which I would like to calculate all possible combinations of the values of a and b. If f is multiplication, I would simply do: a <- 1:5 b <- 1:5 outer(a,b) ## A bit more complicated is this: f <-

Hello, If a matrix with 5 columns has been defined and the first two columns need to be sorted in ascending order, how can this be achieved whilst ensuring the other 3 columns data are in relative position to the sorted columns? Glen Jones [[alternative HTML version deleted]]

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:

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

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

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