similar to: remedial stats education

Hi, a questionaire data-set with more than one row for one Person make me problems. (1) i want create a function which count the used row for the relevant id ! example: id c.row 1 1 1 2 1 3 2 1 2 2 4 1 4 2 4 3 4 4 4 5 (2) i have got a problem to filter & analyse , because the filter criteria is unlucky a row above or under the ratings which i would like to

Hi, I've made a research about how to compare two regression line slopes (of y versus x for 2 groups, "group" being a factor ) using R. I knew the method based on the following statement : t = (b1 - b2) / sb1,b2 where b1 and b2 are the two slope coefficients and sb1,b2 the pooled standard error of the slope (b) which can be calculated in R this way: > df1 <-

Hello, I'm new using R and developing tables. I have a problem in developing a table. In a questionaire I made I ask this question "Please tell me the first three sympthoms caused by Respiratory tract infection you've caught this year", then the people answer three sympthoms, the first mention (Top of mind) is saved in a variable called "P2_A", the second mention in

Is there a way to prepare a questionnaire in R like html forms whose data can be directly populated into R????? [[alternative HTML version deleted]]

Hi, I would like to know how to assign values to a whole vector while keeping its attributes. For example, say I have a <- structure(1:3,x=3) and I want to change the values to 2:4. If I do, a <- 2:4, the attribute x will be lost. I have a workaround for this case, which is to use subset assignment a[1:3] <- 2:4. However, what if I want to also change the length of a? Then this workaround

hi all i would like to know if anyone has a reference on how one would place the "bands" on the pp plot. i want to test whether or not a certain data set comes from a particular distribution (not normal). i've already plotted F(X(j)) vs j/(n+1) where F(x) is the cum dist function, X(j) is the j'th order statistic and n is the sample size. a goole search gave arb references

It seems like the Bayesian folks like to hide. Hey, I just want to get the job done whether using frequency or Bayesian stats. Can anybody suggest a good introduction to Bayesian Analysis? ----- Forwarded message from Ken Beath <kjbeath at kagi.com> ----- To: Joshua N Pritikin <jpritikin at pobox.com> From: Ken Beath <kjbeath at kagi.com> Subject: Remedial stats Hi,

I fitted a GAM model with Poisson distribution to a data with about 200 observations. I noticed that the plot of the residuals versus fitted values show a trend. Residuals tend to be lower for higher fitted values. Because, I'm dealing with count data, I'm thinking that this might be due to overdispersion. Is there a way to account for overdispersion in any of the packages MGCV or GAM?

I'm just learning how to use R right now, so I'm not sure what the most efficient way to organize these data is. I had subjects perform the same task twice with slight changes between the rounds. I want to analyze differences between the rounds. All of the subjects also answered a questionnaire. Putting all of one subject's information on one row seems sloppy. I was thinking about

Dear colleagues, I have really heavy problems in sorting the results of a table according to certain features of the levels in the table. Prerequisites: It all starts with a fairly simple data set, which stores observations of 21 observers (horizontally from 1 to 21; 21 is reference/goldstandard) who diagnosed 42 videos (vertically from 1 to 42). See dump of R-object "input" below in

Hi, I want to use Maximum likelihood to estimate the parameters from my regression line. I have purchased the book "Applied linear statistical models" from Neter, Kutner, nachtsheim & Wasserman, and in one of the first chapters, they use maximum likelihood to estimate the parameters. Now I want to tried it for my self, but couldn't find the right function. In the book, they give

I'm wondering how to choose an appropriate linear model for a given problem. I have been reading Applied Linear Regression Models by John Neter, Michael H Kutner, William Wasserman and Christopher J. Nachtsheim. I'm still not clear how to choose an appropriate linear model. For multi-factor ANOVA, shall I start with all the interaction terms and do an F-test to see with interaction terms

Dear friends, I found the thread on this subject this summer but wonder whether it has been taken any further. I have an important medical problem where X is computed from a three independent and complicated measurements (exchangeable sodium and potassium and total body water - i.e. X = (Nae+Ke)/TBW ) and Y is serum sodium concentration (all data in Edelman, JCI 1958). I have the individual

Hi all, Is there anyone who ever used igraph to calculate the index of "centralization" ? I tried my best but can't find it in igraph. The brief introduction to "centralization" can be found here , and I think it's an important index for measuring the centrality on the aggregated level.(http://faculty.ucr.edu/~hanneman/nettext/C10_Centrality.html) Thank you for any

I've been trying to download from CRAN the floppy versions of the R source files: R-release-1.tar.gz, R-release-2.tar.gz I tried the servers in Seattle, Madison, and the Vienna Technical University. In each case, the file(s) were unavailable. Anne ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Anne E. York National Marine Mammal Laboratory Seattle WA 98115-0070 USA e-mail: anne.york at noaa.gov

Hi, We've encountered a difference in running time between a straight function call and the same call using do.call when the called function generated an error. We've isolated the problem to the following small reproducible example: Consider the following function: foo <- function(nr = 2e6, nc=3, use.do.call = FALSE) { nn <- paste("V", 1:nc, sep="") z <-

If I'm not mistaken, partial R-squared is the R^2 of the quantities plotted in a partial residual plot, so you can base the computation on that. Prof. Fox's `car' package on CRAN has a function for creating those plots, but you need to figure out the way to extract the quantities being plotted. [In any case, the basic tools for doing such computations are all in R, and it

Hi, Can someone recommend a good vulnerability scanning service? I just need the minimum for PCI compliance (it's a sort of credit card processing certification). I got a free scan from https://www.hackerguardian.com/ and their scan reported a number of "Fail" results. I haven't checked them all yet but most seem to be things for which fixes were backported looong ago by The

Hello, I'm looking for a textbook that can explain some of the math behind the intro-to-intermediate stuff like ANOVA, multiple regression, non- parametric tests, etc. A little background: I took an intro stats course last year and would like to further my education. Being as that was the highest (and only) stats class the local community college offers, it looks like I'm on

I am still a little unclear in the difference between randomized block design and two-way factorial design after consulting a few books, including John Rice Mathematical Statistics and Data Analysis. Both put observations in cells corresponding to two factors of many levels. Both use the same computer program to analyze data. It seems that randomized block design can have only one observation