similar to: cochran-grubbs tests results

Displaying 20 results from an estimated 200 matches similar to: "cochran-grubbs tests results"

2009 Feb 14
2
implementing Grubbs outlier test on a large dataframe
Hi! I'm trying to implement an outlier test once/row in a large dataframe. Ideally, I'd do this then add the Pvalue results and the number flagged as an outlier as two new separate columns to the dataframe. Grubbs outlier test requires a vector and I'm confused how to make each row of my dataframe a vector, followed by doing a Grubbs test for each row containing the vector of numbers
2005 Apr 14
2
grubbs.test
Dear All, I have small samples of data (between 6 and 15) for numerious time series points. I am assuming the data for each time point is normally distributed. The problem is that the data arrvies sporadically and I would like to detect the number of outliers after I have six data points for any time period. Essentially, I would like to detect the number of outliers when I have 6 data points then
2010 Nov 30
3
Outlier statistics question
I have a statistical question. The data sets I am working with are right-skewed so I have been plotting the log transformations of my data. I am using a Grubbs Test to detect outliers in the data, but I get different outcomes depending on whether I run the test on the original data or the log(data). Here is one of the problematic sets: fgf2p50=c(1.563,2.161,2.529,2.726,2.442,5.047)
2013 May 17
0
Using grubbs test for residuals to find outliers
Hi, I am a new user of R. This is a conceptual doubt regarding screeing out outliers from the dataset in regression. I read up that Cook's distance can be used and if we want to remove influential observations, we can use the metric (>4/n) (n=no of observations) to remove any outliers. I also came across Grubb's test to identify outliers in univariate distns. (assumed normal) but i
2012 Apr 18
1
Pierce's criterion
Hello all, I would like to rigorously test whether observations in my dataset are outliers. I guess all the main tests in R (Grubbs) impose the assumption of normality. My data is surely not normal, so I would like to use something else. As far as I can tell from wikipedia, Peirce's criterion is just that. The data I am interested in testing is: 1) Continuous on the unit interval 2)
2006 Jul 20
2
(robust) mixed-effects model with covariate
Dear all, I am unsure about how to specify a model in R and I thought of asking some advice to the list. I have two groups ("Group"= A, B) of subjects, with each subject undertaking a test before and after a certain treatment ("Time"= pre, post). Additionally, I want to enter the age of the subject as a covariate (the performance on the test is affected by age),
2007 Apr 25
1
How to identify and exclude the outliers with R?
Hello, everyone, I want to ask a simple question. If I have a set of data,and I want to identify how many outliers there are in the data.Which packages and functions can I use? Thanks. Shao chunxuan. [[alternative HTML version deleted]]
2011 Dec 05
0
ANNOUNCEMENT: Call for Proposals for The R Series from Chapman & Hall/CRC
Chapman & Hall/CRC: The R Series We are delighted to announce that our new series of books on R is up and running, with two books already published and another nine forthcoming (including three set to publish in 2012). We are keen to receive proposals for books covering all aspects of the development and application of R software. If you have an idea for a book, please contact one of the
2007 Nov 05
1
Help with cochran.test
Hi, I have been trying to use the function cochran.test from the Outliers package to test for homogeneity of variance. This works well except when I use transformed data. Would anyone have an idea why it doesn't work and how I could do the cochran test on transformed data? Thanks, Stephanie >library(outliers) > set.seed(1234) > x=rnorm(100) >
2007 Jun 19
5
outlying
hello, are there functions to detecte outlying observations in samples? thanks. ___________________________________________________________________________ [[alternative HTML version deleted]]
2009 Jun 01
1
using "cochran.test()" as a "mcnemar.test()" ?
Hello all I wish to perform a mcnemar.test() for a 5X5 matrix. Wikipedia tells me (http://en.wikipedia.org/wiki/Cochran_test) I should turn to cochran.test. The only place I found it was in the "outliers" package, but the command cochran.test() acts differently then mcnemar.test() , and doesn't take a table as input. Any ideas on how to use it ? #Example code: aa =
2010 Sep 28
2
cochran Q test
Dear all, I am trying to look for a built in function that performs the cochran Q test. that is, cochranq.test(X) where X is a contingency table (maybe a matrix or data.frame). The output will naturally be the test statisitcs, p-value, etc. A quick search on Google gives me the cochran.test in the 'outlier' package, but I had a look at the description of the test and it doesn't look
2005 Jul 28
2
Cochran-Armitage-trend-test
Hi! I am searching for the Cochran-Armitage-trend-test. Is it included in an R-package? Thank you! --
2007 Mar 06
1
Quick question on Cochran-Mantel-Haenszel test
Dear List, I am looking for what B.S.Everitt refers to as Cochrane Method for testing independence in combined 2x2 contingency tables. Is it the same method as the Cochran-Mantel-Haenszel Chi-Squared Test for Count Data in R? Thanks, Serguei [[alternative HTML version deleted]]
2009 Dec 08
0
Cochran C Test - Homogeneity of Variances
Hi List. It may be a very simple question, but I couldn’t find an answer on the internet. Which function (maybe in a specific package) would I use to perform a Cochran C Test for Homogeneity of Variances? Stats package have the mantelhaen.test, but I’m “almost sure” that It’s not what I want, it’s probably the Cochran Q Test. So, any ideas? Thank you for the pacience.
2006 Dec 28
0
Cochran-Armitage statistics
Dear R-enthusiasts, I am trying to do a Cochran-Armitage test for trend in R. After consulting google I found Torsten Hothorn's remark that the 'coin' library could be used. lungtumor <- data.frame(dose = rep(c(0, 1, 2), c(40, 50, 48)), tumor = c(rep(c(0, 1), c(38, 2)), rep(c(0, 1), c(43, 7)),
2017 Dec 22
0
Introducing samplesizeCMH: Power and Sample Size Calculation for the Cochran-Mantel-Haenszel Test
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
2017 Dec 22
0
Introducing samplesizeCMH: Power and Sample Size Calculation for the Cochran-Mantel-Haenszel Test
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
2007 Nov 01
1
Help me in Cochran armitage trend test Coding
Dear sir, I am Shibu John from Thrombosis Research Institute India. It is a multidisciplinary organisation concerned with the interrelated problems of thrombosis and atherosclerosis. I was searching for Cochran armitage trend test program in R. Then I had seen your R coding for C-A trend test. I tried that in the R software. But I can?t run the program due the [Error: could not find function
2009 Feb 09
2
R equivalent of SAS Cochran-Mantel-Haenszel tests?
In SAS, for a two-way (or 3-way, stratified) table, the CMH option in SAS PROC FREQ gives 3 tests that take ordinality of the factors into account, for both variables, just the column variable or neither. Is there an equivalent in R? The mantelhaen.test in stats gives something quite different (a test of conditional independence for *nominal* factors in a 3-way table). e.g. I'd like to