similar to: Linear regression

I'm looking for an icon to represent an R package. Perhaps something like http://cdn2.iconfinder.com/data/icons/DarkGlass_Reworked/128x128/apps/package.png but with the R logo rather than KDE. -- Michael Friendly Email: friendly AT yorku DOT ca Professor, Psychology Dept. York University Voice: 416 736-5115 x66249 Fax: 416 736-5814 4700 Keele Street Web:

Is there an R function that can be used to calculate a sample size for a linear regression: i.e. Given a linear regression: y=f(x,z) i.e. fit1<-lm(y~x+z) is there a function which can be passed coef(z), SE(z), and other parameters to determine a sample size based on z, SEz and other information from the regression? Thanks, John John Sorkin M.D., Ph.D. Chief, Biostatistics and Informatics

R 2.7 Windows XP I have two model that have been run using exactly the same data, both fit using glm(). One model is a linear regression (gaussian(link = "identity")) the other a quasipoisson(link = "log"). I have log likelihoods from each model. Is there any way I can determine which model is a better fit to the data? anova() does not appear to work as the models have the

Hi list, I have code which reads data from sql server using RODBC in R version 2.12.1. The code used to be ok, till today when I get the following error. The data does not have any problem, but if I run the code in differnt pc, it runs till different number of trial then it fails, for example on one pc, it runs up to 30 times, other pc up to 66 times, then it fails. Any help please? [1] "so

Windows XP R 2.3.1 I have a funciton fit1<-lm(y~x+z) Is there a function that will produce a 3-dimensional plot of y,x,z? I looked at the help files, but did not find a clean answer to my question. Thanks, John John Sorkin M.D., Ph.D. Chief, Biostatistics and Informatics University of Maryland School of Medicine Division of Gerontology Baltimore VA Medical Center 10 North Greene Street

I am trying to plot where data points from a give subject are connected by a line. Each subject is represented by a single row of data. Each subject can have up to five observations. The first five columns of mydata give the time of observation, columns 6-10 give the values at each time point. Some subjects have all data, some are missing values. The code I wrote to draw the plot is listed below.

Hello, I would like to fit a linear regression and when I use summary(), I got the following result: Call: lm(formula = weight ~ group - 1) Residuals: Min 1Q Median 3Q Max -1.0710 -0.4938 0.0685 0.2462 1.3690 Coefficients: Estimate Std. Error t value Pr(>|t|) groupCtl 5.0320 0.2202 22.85 9.55e-15 *** groupTrt 4.6610 0.2202 21.16 3.62e-14

Forgive my resending this post. To data I have received only one response (thank you Bert Gunter), and I still do not have an answer to my question. Respectfully, John Windows XP R 2.12.1 contrast package. I am trying to understand how to create contrasts for a model that contatains an interaction. I can get contrasts to work for a model without interaction, but not after adding the

R 2.8.1 Windows XP I am trying to analyze repeated measures data (the data are listed at the end of this Email message) and I need help to make sure that I have properly specified my model, and would like to know why lmer does not return a p value for Group, my fixed effect. My subjects are divided into two groups (variable GROUP), individual subjects are indicated by the variable SS, Value is

I am trying to plot some data, but have got some difficulties with labels on the tick marks on the x-axes. There are 20 data points. All I want to do is to plot the Loss versus Lines. When I use xyplot, the first tick mark starts from 2 rather than 1, and also there is a NA as the final tick mark. Here is the R code you code give it a try: Would any body be able to fix this, please?

Hi List, Would you please send me a good link to talk me through on how to write a R package? thanks Alireza [[alternative HTML version deleted]]

R 2.8.1 windows XP I am trying to learn how to use the boot function to perform a bootstrap of a regression. I have written a short trial program, shown below. Clearly I have done something wrong as the output of each of the 100 bootstrap values for the regression are exactly the same - there does not appear to be any bootstrap respampling!. What have I done wrong? # Define function to be run.

Hi list, I have a real problem with plotting US state map. When I try to plot the northern state, there will be some blank space in the top of graph (see case 1 example), and when I plot southern states, there will be a blank space in the bottom of plot (see case 2). I spent almost 2 days to figure out a solution, but could not. Would you help me if you know what the problem is? Regards, Alireza

Hi List, Is anybody aware of any R console available for Android mobile? I know that there is one for Iphone. thanks, Alireza [[alternative HTML version deleted]]

I am looking for a package that will allow me to choose R (a real number) that minimizes the correlation of y and x^R, i.e. find R such that corr(y,x^R) is minimized. Any suggestions for packages I might look at would be helpful. Thanks, John John David Sorkin M.D., Ph.D. Chief, Biostatistics and Informatics University of Maryland School of Medicine Division of Gerontology Baltimore VA

Folks, Two simple questions : (1) I have a data set (call it data.xls) in a folder in my hard drive. How do I perform a simple regression between two variables from that data set? After I click on 'R', what exactly do I type in? (2) Where do I get to see the complete library of packages offered by R? In particular, I am interested in quantile regression and logistic regression.

R2.1.1 Win 2k I have a function, B, within a function, A. I would like to have B print the name of the argument passed to it (not the value of the arguments). i.e., A<-function() { B<-function(x,y) { fit1<-lm(y~x,data=jo) print(summary(fit1) I want B to print the string "age" and the string "height". } B(age,height) }

Dear r-community, Today I have completed my PhD.  I would like to take this opportunity to thank the r-community for helping me with the r-coding.  I use r to do data manipulation during my PhD and I benefit a lot through the discussion in the r-forum. I will continue using R and help the others too. Thank you so much. Regards, Roslina UniSA. [[alternative HTML version deleted]]

Hi list, Does anyone know the code behind rlnorm(n, meanlog = 0, sdlog = 1)? I am going to write it in c#. thanks Alireza [[alternative HTML version deleted]]

Hi List, If I have a date format as: d <- "2001/1/1" I can easily convert it to number by using as.Date(d). But if I have d<-"1/1/2001", it does not work. Does anyone know how I can convert it using pre-written function in R? Regards, Alireza [[alternative HTML version deleted]]