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Cannot Compute Exact P-values With Ties

So did I manage to prove that the application of this new methodology made that more than half of the class failed the course? Batch Effect normalization with Combat generates error I have 6 batches (10 samples in each) from 6 arrays that we want to normalize for batch effect wi... More specifically, there are three Kendall tau statistics--tau-a, tau-b, and tau-c. Kendall's tau is not Spearman's--they are not the same, but they are also quite similar. check my blog

I think this is reasonably clear from ?wilcox.test. This is my pillow Was there no tax before 1913 in the United States? I need a corrected Spearman mostly to compare a study with existing studies that only report the corrected Spearman and not tau. asked 2 years ago viewed 1365 times active 2 years ago Related 11python's scipy.stats.ranksums vs.

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' > - Can I switch from past tense to present tense in an epilogue? Nevertheless, it's in the right ballpark.

Using the Mann-Whitney-Wilcoxon Test, we can decide whether the population distributions are identical without assuming them to follow the normal distribution. Are 14 and 21 the only "interesting" numbers? Newton's second law for individual forces How can tilting a N64 cartridge cause such subtle glitches? In it, you'll get: The week's top questions and answers Important community announcements Questions that need answers see an example newsletter By subscribing, you agree to the privacy policy and terms

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). What does this mean for my data? > > If you have two identical values in your data, these are called > ties. How to convert numbers to currency values? try this maSigPro edesign and error message Hi, I have 6 RNA-Seq samples in different time points and I would like to find DE genes chang...

Hence, the hypothesis that MORE THAN 50% will fail with this teaching methodology is still not proven (the confidence interval is going across 50% meaning that the true rate could be ADD REPLY • link written 6.1 years ago by Chuangye • 70 Please log in to add an answer. It's sort of turning upside down the scientific process, you should make a hypothesis before the experiment, and have a clue about possible analysis or test. 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

Safely adding insecure devices to my home network Can a countable number of intersections of subsets or their complements be the null set? I want to basically test if a value x is significantly within/outside a distribution d. more hot questions question feed lang-r about us tour help blog chat data legal privacy policy work here advertising info mobile contact us feedback Technology Life / Arts Culture / Recreation But the warning messages rised up,such as "In wilcox.test.default(A, B[, 1]) : cannot compute exact p-value with ties".

automobiles. > mtcars$mpg  [1] 21.0 21.0 22.8 21.4 18.7 ... http://electrictricycle.net/cannot-compute/cannot-compute-exact-p-values.html You're on your own for figuring out what the differences among these procedures are and which would be best to use ...) The results make sense here -- the problem is What is the best formula to date to compute it with a lot of ties? How to replace inner text with yanked text What are 'hacker fares' at a flight search-engine?

This is 63% with a 95% confidence interval of 42.3% to 80.6%. 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. 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... http://electrictricycle.net/cannot-compute/cannot-compute-exact-p-value-with-ties.html I did this and obtained slightly different results (this package throws a warning indicating that it is not maintained anymore - however the last update is only 2 months old) –Jealie

Teenage daughter refusing to go to school more hot questions question feed lang-r about us tour help blog chat data legal privacy policy work here advertising info mobile contact us feedback more stack exchange communities company blog Stack Exchange Inbox Reputation and Badges sign up log in tour help Tour Start here for a quick overview of the site Help Center Detailed Setting elementMetadata in genomicranges list objects I thought this would be easy, but once again working with genomicranges is not intuitive to me. ...

The system returned: (22) Invalid argument The remote host or network may be down.

Please try the request again. I think this is reasonably clear from ?wilcox.test. Notice the p-value is unchanged, meaning the t-distribution assumption is still being used, as seen by ?cor.test. –Ashe Oct 31 at 15:03 add a comment| up vote 2 down vote cor.test Wilcox u-test ‹ Previous Topic Next Topic › Classic List Threaded ♦ ♦ Locked 3 messages Dirkheld Threaded Open this post in threaded view ♦ ♦ | Report Content

Your power will certainly vary with the sizes of both data sets, but that's more or less inevitable (there may be a more powerful way to achieve the same general goal, Hoping this helps, Ted. >> - Is that a problem for significance testing? > > If there are just a few ties, you should not worry, but re-check how > your n-dimensional circles! More about the author Alternatively a Wilcoxon-Mann-Whitney test might be used, as long as proper account is taken of the level of ties in the data because of the discreteness.

Could you give me some suggestions? Why allow shared_ptr? up vote 4 down vote favorite A new methodology has been proposed for teaching English to undergraduate students. Your cache administrator is webmaster.

While the distribution is somewhat skew and discrete, the sample size is large enough that the t-distribution will be a reasonable approximation. more stack exchange communities company blog Stack Exchange Inbox Reputation and Badges sign up log in tour help Tour Start here for a quick overview of the site Help Center Detailed R › R help Search everywhere only in this topic Advanced Search What are ties?