similar to: Homework help: Is this how CI using t dist are constructed?

I'm looking for a function in R similar to t.test() which was generously pointed out to me yesterday, but which can be used for normally distributed data. To recap yesterday: > x <- scan() 1: 62 52 68 23 34 45 27 42 83 56 40 12: Read 11 items > alpha<- .05 > t.test(x) One Sample t-test data: x t = 8.8696, df = 10, p-value = 4.717e-06 alternative hypothesis: true

Is this how a t hypothesis test is done when I don't have the actual data, but just the summarized statistics: > #Homework 9.2.6 [1] > n<-31 > xbar<-3.10 > s_x<-1.469 > m<-57 > ybar<-2.43 > s_y<-1.35 > s_pooled<- (((n-1)*s_x^2) + ((m-1)*s_y^2)) / (n + m - 2) > s_pooled [1] 1.939521 > t_obs <- (xbar - ybar) / (s_pooled * (sqrt(1/n + 1/m)))

We just studied randomized block design analysis in my statistics class, and I'm trying to learn how to do them in R. I'm trying to duplicate a case study example from my textbook [1]: > # Case Study 13.2.1, page 778 > cd <- c(8, 11, 9, 16, 24) > dp <- c(2, 1, 12, 11, 19) > lm <- c(-2, 0, 6, 2, 11) > table <- data.frame(Block=LETTERS[1:5], "Score

I'm trying to get R to simulate the sum of the values on 10 fair dice (yes, it's related to a homework problem, but is not the problem itself). I tried to do this: > rep(sum(sample(1:6,100,replace=T)), times=10) [1] 341 341 341 341 341 341 341 341 341 341 and noticed that sum(sample()) seems to be only evaluated once. How can I overcome this, so that I get a vector of values that

In Henric's recent post, he included this output: @BOOK{R:Harrell:2001, AUTHOR = {Frank E. Harrell}, TITLE = {Regression Modeling Strategies, with Applications to Linear Models, Survival Analysis and Logistic Regression}, PUBLISHER = {Springer}, YEAR = 2001, NOTE = {ISBN 0-387-95232-2}, URL =

I'm trying to get R, Sweave, ESS and XEmacs or emacs all installed and working together on my Windows XP Pro system. I've got R 2.6.0 working just fine, installed from the R Windows installer. I also have CYGWIN_NT-5.1 with XEmacs 21.4 working okay. Can anyone point me to any documentation on how to bring these together so that R code typed in Xemacs can be run in R? I found the ESS

I hope this question is sufficiently different from the other requests for book recommendations that it's not repetitious. If not, I apologize in advance. I'm curious what standard reference books working statisticians, or biostatisticians, have within easy reach of their desk. I'm a computer systems administrator, and have a two-foot bookshelf directory under my monitor that contains

[If I knew who to report this to privately, I would. Sorry to embarrass anyone who's just trying to contribute to the R-project.] There seems to be some oddities with the RSiteSearch web page. When I enter 'RSiteSearch("console")' I'm taken to http://search.r-project.org/cgi-bin/namazu.cgi?query=console&max=20&resu

There must be a better way to select the rows after 22-Apr-2004 and before 01-Sep-2004 with a temperature below 65 than this: > before2sw1 <- subset(energy.data, as.Date(start, format="%d-%b-%y") < as.Date("01-Sep-04", format = "%d-%b-%y")) > before2sw2 <- subset(before2sw1, as.Date(start, format="%d-%b-%y") >=

[Yes, this is related to a homework problem, but is not the problems itself.] In my mathematical statistics class, we've just learned about properties of estimators, and I can now solve manually problems like this: A sample of size n = 16 is drawn from a normal distribution where sigma = 10 but mu is unknown. If mu = 20, what is the probability that the estimator mu hat = Y bar will lie

I've been working with R for all of about 8 hours, so anyone with more experience than this should be able to help me. General comments about my methods of work are also welcomed. I have a table that I've imported thusly: > w <- read.table("woodford.data", header=T) > w start therms gas KWHs elect temp days 1 10-Jun-98 9 16.84 613 63.80 75 40 2

I think I've gotten my Emacs/Sweave/R system set up correctly, thanks to Vincent and Jim, but I haven't been successful getting my first document produced. I'm trying to use one of Friedrich Leisch's examples, http://www.ci.tuwien.ac.at/~leisch/Sweave/example-1.Snw. I cut and pasted the text into a document sweaveexample.Rnw in Emacs. It seemed to be processed successfully with R:

I'm trying to solve a homework problem using R. The problem gives a list of cricket chirps per second and corresponding temperature, and asks to give the equation for the linear model and then predict the temperature to produce 18 chirps per second. So far, I have: > # Homework 11.2.1 and 11.3.3 > chirps <- scan() 1: 20 2: 16 3: 19.8 4: 18.4 5: 17.1 6: 15.5 7: 14.7 8: 17.1 9: 15.4

I'm attempting the heruclean task of teaching myself Introductory Statistics and R at the same time. I'm working through Peter Dalgaard's Introductory Statistics with R, but don't understand why the answer to one of the exercises works. I'm hoping someone will have the patience to explain the answer to me, both in the statistics and R areas. Exercise 6.1 says: The zelazo data

I've been given the job of extracting some data from the United States 2000 census (files at http://www2.census.gov/census_2000/datasets/Summary_File_2/Maryland/all_ Maryland.zip 52M). I'm only interested in Census Block Groups (CBGs) located within Baltimore City, Maryland. Additionally, I just have to extract certain data fields. I think I'll be using Summary File 2. This is my first

I'm trying to learn statistics and R at the same time. I have an undergraduate science degree and one year of calculus (30 years ago), but never took a stats course. I hope to take some stats courses in the next year, but thought I would start to see how much I could teach myself. I work for an organization that analyses behavior change communication programs regarding HIV/AIDS and

Dear All, This is a question to sound out possibilities. I am with the Faculty of Natural and Agricultural Sciences at the University of Western Australia, representing a few of the more statistically minded in the faculty. Essentially, there have been problems in the past with software support, changing over statistical software, and paying lots of money for it. In R you have an advanced

FWIW, here's a little data set I collected yesterday while working as an election judge in a precinct in Maryland: End DEM REP IND LIB OTH 8:00 40 12 7 1 0 9:00 30 7 3 0 0 10:00 35 13 6 0 0 11:00 31 10 8 0 0 12:00 23 4 2 0 0 1:00 23 5 0 0 0 2:00 20 8 1 0 0 3:00 24 5 6 0 0 4:00 15 6 4

Hi I am performing an analysis of variance with two factors, each with two levels. I have differing numbers of observations in each of the four combinations, but all four combinations *are* present (2 of the factor combinations have 3 observations, 1 has 4 and 1 has 5) I have used both anova(aov(...)) and anova(lm(...)) in R and it gave the same result - as expected. I then plugged this into

I'm having trouble using the read.mtp function in the foreign package to import datasets from minitab (.mtw) format. Specifically, each file I try to import fails to load any data beyond a header row stating the version of Minitab that saved the dataset. I get this error: incomplete final line found by readtableHeader on 'income.mtw' The dataset appears to be complete (ie, using