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Cannot Compute Exact P Values


Uwe Ligges ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code. What are the alternatives to compound interest for a Muslim? So did I manage to prove that the application of this new methodology made that more than half of the class failed the course? Now the ranks are not unique anymore and hence exact > p-values cannot be calculated. > And since you do not know this, it might be worth to note that > have a peek at these guys

Is there a wage gap between smokers and non-smokers? The nth numerator What is the simplest way to put some text at the beginning of a line and to put some text at the center of the same line? It's generally a bad idea to ask a question this way, as the question cannot be answered without knowing how the data was obtained, what are the hypothesis of the experiment. I need a corrected Spearman mostly to compare a study with existing studies that only report the corrected Spearman and not tau. http://r.789695.n4.nabble.com/What-are-ties-Wilcox-u-test-td857059.html

Cannot Compute Exact P-value With Ties Spearman

Was there no tax before 1913 in the United States? Wilcox u-test Dirkheld wrote: > Hi, > > When I execute a Wilcox u-test on two variables I receive a warning : > 'cannot compute exact p-value with ties' > - In this respect, I think ?wilcox.test is misleading. r normal-distribution share|improve this question edited Jun 23 '11 at 1:54 Theta30 487215 asked Jun 22 '11 at 15:28 evdstat 8125 5 Unless your data are artificially generated by a

Problem Without assuming the data to have normal distribution, decide at .05 significance level if the gas mileage data of manual and automatic transmissions in mtcars have identical data distribution. up vote 4 down vote favorite A new methodology has been proposed for teaching English to undergraduate students. The result, in my case, was exactly the same, but without the warning about ties. Spearman Correlation Ties Is "she don't" sometimes considered correct form?

What did John Templeton mean when he said that the four most dangerous words in investing are: ‘this time it’s different'? In Wilcox.test.default Cannot Compute Exact P-value With Ties Along the lines of the signed-rank test, you could do a sign test ... Please consider that I do not have a former education in statistics. http://www.r-tutor.com/elementary-statistics/non-parametric-methods/mann-whitney-wilcoxon-test Here is the standard value of r for small, medium, and large sizes.

Is it acceptable to ask an unknown professor for help in a related field during his office hours? Kendall Tau B In R We can depict numbers only up to a number of digits. Thank you. > wilcox.test(A,B[,1]) Wilcoxon rank sum test with continuity correction data: A and B[, 1] W = 49, p-value = 0.00184 alternative hypothesis: true location shift is not equal to While people commonly think that the Wilcoxon test (or its equivalent the Mann-Whitney U test) is a test of "shift in location", this is only a special case of the class

In Wilcox.test.default Cannot Compute Exact P-value With Ties

In case that all my analysis is wrong, could somebody guide me about how to prove that the application of the new methodology had an effect in the huge number of First Skills to Learn for Mountaineering Mysterious creeper-like explosions For a better animation of the solution from NDSolve Are 14 and 21 the only "interesting" numbers? Cannot Compute Exact P-value With Ties Spearman up vote 4 down vote favorite 2 My shortened data is: y <- c (2,2,1,5,6,7,1,2,1,6,6,7,3,2,4,4,4,4,3,3,9,1,1,9) I firstly normalize my data: y_scale <- scale(y) Then, I generate a model dataset with normal In Wilcox.test.default Cannot Compute Exact P-value With Zeros You have two identical values in your data, these are the ties.

In situations in which i needed a non-parametric rank correlation statistic, i have always chosen tau over rho. http://electrictricycle.net/cannot-compute/cannot-compute-exact-p-value-with-ties.html Can one bake a cake with a cooked egg instead of a raw one? A Wilcoxon Signed-rank test checks how likely it would be W=8.5. It is, in effect, based on an estimate of P(X < Y). Wilcoxon Rank Sum Test With Continuity Correction

share|improve this answer answered Jun 22 '11 at 15:52 user603 14.8k14077 Thanks for user603's comment. –evdstat Jun 22 '11 at 16:17 I tried to do this as You cannot remove your comments by yourself. share|improve this answer edited Jun 23 '11 at 7:35 answered Jun 23 '11 at 7:26 Theta30 487215 add a comment| Your Answer draft saved draft discarded Sign up or log check my blog Why allow shared_ptr?

wilcox.test(x, ...) wilcox.test(x, y, alternative = c("two.sided", "less", "greater"), mu = 0, paired = FALSE, exact = NULL, correct = TRUE, conf.int=FALSE, conf.level = 0.95, ...) x,y: Unnormally distributed data sets Wilcoxon Rank Sum Test With Ties In R Now we are looking at how a Wilcoxon Signed-rank test works. Content Search Users Tags Badges Help About FAQ Access RSS Stats API Use of this site constitutes acceptance of our User Agreement and Privacy Policy.

In a company crossing multiple timezones, is it rude to send a co-worker a work email in the middle of the night?

For instance, tau-b: Kendall_tau_b = (P - Q) / ( (P + Q + Y0)*(P + Q + X0) )^0.5 P: number of concordant pairs ('concordant' means the ranks of each Pvclust:Error In Clustering Hi all, I'm trying to cluster 128 genes from mRNA-seq data so as to see which genes group togeth... Your cache administrator is webmaster. Grouping Factor Must Have Exactly 2 Levels This could be very easily gleaned from a quick perusal of Google and would have been better off asked on http://stats.stackexchange.com/ ADD COMMENT • link modified 6.1 years ago • written

Koji Yatani, 2015/02/14 07:01 Hodges-Lehmann is not very common yet in the field of HCI. response to followup question in comments: A comparison of numeric grades might be addressed by a two sample t-test (possibly with unpooled variance and Welch-Satterthwaite adjustment to df). Setting elementMetadata in genomicranges list objects I thought this would be easy, but once again working with genomicranges is not intuitive to me. ... news What does this mean for my data?

More specifically, there are three Kendall tau statistics--tau-a, tau-b, and tau-c. I use following to read `bed` file, and I want to get... (Closed) Using pamr.train to find Shrunken Centroid I have recently started learning how to use R, and I am asked 5 years ago viewed 3797 times active 5 years ago 13 votes · comment · stats Linked 184 Is normality testing 'essentially useless'? 1 Is the dataset Normally distributed? Peter Dalgaard p.dalgaard at biostat.ku.dk Thu Jan 12 16:28:17 CET 2006 Previous message: [R] wilcox.test warnig message p-value where are the zeros in the data?

I have a linear regression model on someone else's unpublished microarray data in which I'm testi... You might want to look at at statistics text, there is some discussion here on dealing with ties. asked 1 year ago viewed 556 times active 1 year ago Get the weekly newsletter! PD.

automobiles. > mtcars$mpg  [1] 21.0 21.0 22.8 21.4 18.7 ... But you have to format the data for the Wilcoxon test with coin. And there were no ties (give credit to R for that). Which movie series are referenced in XKCD comic 1568?

For meaningful results you should not normalize. You can see that after replacing your original data with their ranks (midranks for ties) and using method="pearson", you will get the same result: > cor.test(rank(c(1,2,3,4,5,6,7,8)), rank(c(0,0,0,0,0,0,7,8)), method="pearson") Pearson's product-moment correlation As you can see at help page the $p$-values are not exact if there are ties because "the continuous distributions do not generate them." So the theory (and hence the algorithm) SciClone not numeric error I tried to use sciClone on test data prior to applying any script on my actual patient database, ...

Is there a ties-corrected version of Spearman in R? Fixed. r correlation share|improve this question edited Apr 11 '15 at 17:34 Ben Bolker 98.8k6141230 asked May 22 '12 at 23:12 Mulone 1,53463160 add a comment| 5 Answers 5 active oldest votes of Biostatistics PO Box 2099, 1014 Cph.

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