similar to: Sample Size Calculation

Hello- I have run an ANOVA on 4 treatments with unequal sample sizes (n=9,7,10 and 10). I want to determine where my sig. differences are between treatments using a Bonferroni test, and have run the code: pairwise.t.test(Wk16, Treatment, p.adf="bonf") I receive an error message stating that my arguments are of unequal length: Error in tapply(x, g, mean, na.rm = TRUE) :

Dear All I am kind of stuck up with a code a part of which seems to be causing a problem, or at least I think so. May be the community can help me. It’s simple but I suppose I am missing something. I generate a data matrix X, say of order n*p, where n represents independent row-vectors and p correlated col vectors. Let the row representation be X = (X’_1, . . ., X’_n)’. I generate the

Hi everyone. I need to do a sample size calculation for a one sample based on a CI interval of +- 5% of the proportion, we expect to have a rate of 0.07 based on similar studies. I have looked at the pwr-package as well as the power.prop.test function, but I can't see how to make either do what I need. Could anyone point me to a function, or explain how to do this will the functions in pwr?

Dear R users, I am happy to announce the new package `samplesizeCMH` is now available on CRAN <https://cran.r-project.org/package=samplesizeCMH>. The `samplesizeCMH` package will compute power and sample size for the Cochran-Mantel-Haenszel test for stratified 2x2 tables. There are also several helper functions for working with 2x2 tables, such as converting a proportion into an odds

Dear R users, I am happy to announce the new package `samplesizeCMH` is now available on CRAN <https://cran.r-project.org/package=samplesizeCMH>. The `samplesizeCMH` package will compute power and sample size for the Cochran-Mantel-Haenszel test for stratified 2x2 tables. There are also several helper functions for working with 2x2 tables, such as converting a proportion into an odds

Hi, I'm try to compute the minimum sample size needed to have at least an 80% of power, with alpha=0.05. The problem is that empirical proportions are really small: 0.00154 in one case and 0.00234. These are the estimated failure proportion of two medical treatments. Thomas and Conlon (1992) suggested Fisher's exact test and proposed a computational method, which according to their table

I am getting a repeated error when I try to run a logistic regression in R 2.8.1 >(glm(prop1~x1,data=glm1,family=binomial("logit"),weights=nt1)) Error in model.frame.default(formula = prop1 ~ x1, data = glm1, weights = nt1, : invalid type (list) for variable 'x1' x1 is multistate categorical (3 categories). 2 of the categories have 12 observation, one has 9. Is this what

Hello, I have a general formatting question. I have two columns of data: ColA <- c("m", "m", "m", "m") ColB<- c("d","d","d","d") And I would like to reorder them into a new column that looks like this: ColC<-

I'm new to Wine, but am following instructions from http://www.youtube.com/watch?v=da-1pKWp4Z0&feature=related I have the game files on a CD i burned, and thats fine. I select AutoRun.exe (everthing directory wise looks the same as on the video), and it successfully takes me through the end of the installation. WHen the game is done installing, I click "Finish" to finish the

This is in followup to a thread on R-help with subject "Sampling". I claim that R does the wrong thing by default when sampling with unequal probabilities without replacement - the selection probabilities are not proportional to 'prob', for any draw after the first: I suggest that R do what S-PLUS now does (though you're free to choose a better implementation). What S-PLUS

Hello, I am hoping someone could shed some light on power calculations for me. I have two small data sets of unequal sample size after NA removal (m = 5, f = 7). m <- c(2.0863, 2.1340, 2.1008, 1.9565, 2.0413, NA, NA) f <- c(1.8938, 1.9709, 1.8613, 2.0836, 1.9485, 2.0630, 1.9143) In a R help message/reply from Sep 30, 2001, it was noted that the "power.t.test" function

Power calculations two sample test for proportions is very useful. Is there a way however, to get away from the two samples being of the same size. What would happen if one had n=15 in the one sample and n=45 in the other sample. Farrel Buchinsky, MD Pediatric Otolaryngologist Allegheny General Hospital Pittsburgh, PA **********************************************************************

hey all, I've been dying to be able to play roller coaster tycoon 2 on my macbook using wine and winebottler, but im having some problems. Everytime i try to download the program, it gets to the spot where it says turn on coreaudio, and then stalls, and then an error message comes up saying prefix creation exited with error, followed by, you find a logfile to help with degguing on your

Hi, all I have a rather un-ideal dataset that I am trying to work with, and would appreciate any advice you have on the matter. I have 4 years worth of data taken at 3 depth-zones from which samples have been taken at random. I am looking at the abundance of organism A between depth zones and across years, and am interested in the possible interaction of organism A distributions shifting

I'm dealing with a classification problem using ordinal logistic regression. In the case of binary logistic regression with unequal proportions of 0's and 1's, a threshold in the interval [0,1] has to be adapted to transform back the predicted probabilities into 0 and 1. This can be done quite straightforward using e.g. the Kappa statistics as accuracy criterion. With

Dear R experts, I'm beginner. My question about ANOVA for unequal sample sized data should be obsolete but I can not clarify it. I have a dataset from 23 males and 18 females. I measured one condition('cond') with 4 levels. So I'd like to see main effect of gender, cond and gender by cond interaction and also postHoc test. (In fact, I have to do anova 90 times) * 1. Question

HI All: Can anyone give me the formulae/steps for calculating the type III sum of squares for an unbalanced 2-way ANOVA design? Eg. we are looking at 8 treatments x 4 doses, with unequal numbers of replications within the groups. I really need the stepwise calculation, as I would try to put it in my own code (possibly in Visual Basic) to automate the task. Thanks very much. Karth.

Hi I have the RCT 3KVA Axpert solar hybrid inverter. It is also known as the MPP Solar PIP-MS series, the IPS-4000WM and the Voltronic Axpert MKS. I am trying to monitor the inverter using NUT on a Raspberry Pi (I have tried Ubuntu as well with the same results). I have tried most of the drivers with no success. The inverter came with the ViewPower software so I assumed that my best chance

hi, i am new in this field. do favorite<http://stackoverflow.com/questions/36404707/simulation-study-of-2-sample-test-on-different-combination-of-factors#> If I wish to conduct a simulation on the robustness of two sample test by using R language, is that any ways in writing the code? There are several factors (sample sizes-(10,10),(10,25),(25,25),(25,50),(25,100),50,25),(50,100),

Hi, I have two unequal patient groups belonging to different geographic locations, treated by different drug regimens and their survival data. N1=150 and N2=60 In each group of data there are three strata for one independent variable- treatment status (2=two drugs administered, 1=only one conventionally used drug administered, 0=no drug administered), dead or not and months to death. In order to