similar to: Chi Square with two tab-delimited text files

Hi everybody I'm having some unexpected errors from the 'by' function when using it to apply the mean function (by a factor) to a dataframe of numerical variables. The following piece of toy code demonstrates: myDataF<-warpbreaks myDataF$X<-runif(54) # creating an additional numerical variable in warpbreaks for purposes of this demo

Dear R help I have been trying to conduct a chi square test on two groups of variables to test whether there is any relationship between the two sets of variables chisq.test(oxygen, train) Pearson's Chi-squared test data: oxygen X-squared = 26.6576, df = 128, p-value = 1 > chisq.test(oxygen) Pearson's Chi-squared test data: oxygen X-squared = 26.6576, df = 128,

Timothy, I believe you are mistaken. Fisher's exact test give the correct answer even in the face of small expected values for the cell counts. Pearson's Chi-square approximates Fisher's exact test and can give the wrong answer when expected cell counts are low. Chi-square was developed because it is computationally "simple". Fisher's exact test, particularly with tables

Hi All, I woul like to ask you a couple of questions on chisq.test. First, I have 40 flies, 14 males and 26 females and I want to test for an a priori hypothesis that the sex ratio is 1:1 sex<-c(14,26) pr<-c(1,1)/2 chisq.test(se, p=pr, correct=TRUE) Chi-squared test for given probabilities data: sex X-squared = 3.6, df = 1, p-value = 0.05778 If my calculations are correct, this is

Is Pearson's Chi-Square test for contingency tables asymptotically unbiased for large tables (large degrees of freedom) regardless of the expected values in each cell? The rule of thumb is that Pearson's Chi-square should not be used when large numbers of cells have expected values < 5. However, I compared the results on 4x4 contingency tables for R's chisq.test using chi-square

I was asked by my boss to do an analysis on a large data set, and I am trying to convince him to let me use R rather than SPSS. I think Sweave could make my life much much easier. To get me a little closer to this goal, I ran my analysis through R and SPSS and compared the resulting values. In all but one case, they were the same. Given the matrix [,1] [,2] [1,] 110 358 [2,] 71 312 [3,]

I want to calculate chi square test of goodness of fit to test, Sample coming from Poisson distribution. please copy this script in R & run the script The R script is as follows ########################## start ######################################### No_of_Frouds<- c(4,1,6,9,9,10,2,4,8,2,3,0,1,2,3,1,3,4,5,4,4,4,9,5,4,3,11,8,12,3,10,0,7) N <- length(No_of_Frouds) # Estimation of

Sir, I have a problem here while applying chisquare test to the following Data ( below the subject of this mail) ...when I wanted to test the significance using three different free statistical packages, here R, EpiInfo and OpenEpi. *Only OpenEpi accepts the test based on Cochran's Recommendations. * R says " chi squared approximation may be incorrect." Does it mean the same as

An organization has asked me to comment on the validity of their recent all-employee survey. Survey responses, by geographic region, compared with the total number of employees in each region, were as follows: > ByRegion All.Employees Survey.Respondents Region_1 735 142 Region_2 500 83 Region_3 897 78

Dear All, I have a problem understanding the difference between the outcome of a fisher exact test and a chi-square test (with simulated p.value). For some sample data (see below), fisher reports p=.02337. The normal chi-square test complains about "approximation may be incorrect", because there is a column with cells with very small values. I therefore tried the chi-square with

R 2.12 windows 7 I am summary data that I would like to make into a 2x2 table representing counts positive vs. negative counts: 28/289 20/276 My table should look something like the following: group1 group2 Positive 28 20 Negative 289 276 How can a (1) create the 2x2 table (2) run a chi square test on the table? I have tried the following code, but I

How i can perform a Pearson's Chi-squared Test in this data set: | Outcome -----------------+-----------+----------------------------------+ Treatment | Sex | None |Some | Marked | Total -----------------+------------+--------+--------+-------------+ Active | Female | 6 | 5 | 16 | 27

Hi every one How are you? after a days and searching in forums i still can not find some things that helping me to connect Rails with postgre SQL of course those are helpful but not for a stupid person like me :D So i need my friends helping me here and advice me to how can i connect this two things (ROR and Postgre Sql) I need your help so much My eyes going blind because of searching and

Hello, I'm trying to calculate a chi-squared test to see if my data are different from the theoretical distribution or not: chisq.test(rbind(c(79, 52, 69, 71, 82, 87, 95, 74, 55, 78, 49, 60),c(80,80,80, 80, 80, 80, 80, 80, 80, 80, 80, 80))) Pearson's Chi-squared test data: rbind(c(79, 52, 69, 71, 82, 87, 95, 74, 55, 78, 49, 60), c(80, 80, 80, 80, 80, 80, 80, 80, 80, 80, 80,

Hi, As you may have noticed, since last year, we (Google's CUDA compiler team) have contributed quite a lot to the effort of optimizing LLVM for CUDA programs. I think it's worthwhile to write some docs to wrap them up for two reasons. 1) Whoever wants to understand or work on these optimizations has some detailed docs instead of just source code to refer to. 2) RFC on how to improve

I am getting "Chi-squared approximation may be incorrect in: chisq.test(x)" with the data bleow. Frequency distribution of number of male offspring in families of size 5. Number of Male Offspring N 0 518 1 2245 2 4621 3 4753 4 2476 5

Hello, I am trying to print out ANOVA summaries --- as returned by summary (aov(...))--- in tab-delimited format, either to a file or to the console, but so far I haven't been able to figure out a solution. My particular ANOVA has repeated measures, so it is an instance of class aovlist. Can anyone offer any suggestions? I am relatively new to R, so please forgive me if I am missing

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Hello Friends I want to generate tab-delimited text file of my every users information in once. i have a button called EXPORT on my page when i clicked on this button than i want to generate tab-delimited text file for every users information. can anybody give any snippet of code or any idea for this Thanks -- Posted via http://www.ruby-forum.com/.

my csv file is very simple - just one line for purpose of this test: 0{TAB}0 and read function is this: csvdata = read.csv(file="d:/s/test.csv",head=FALSE,sep="\t") then error comes: Error in source("d:/test.csv") : d:/test.csv:1:9: unexpected numeric constant 1: 0 0 but when I change delimiter to ; (colon) then error not shows up anymore -- View this