Re: [R] significance test interquartile ranges

2012-07-15 Thread peter dalgaard
On Jul 14, 2012, at 19:58 , Schaber, Jörg wrote: > Dear Peter, > > thanks for your clarifications. Sample size is around 200 in each group. > Would that justify your approach? It's certainly better than 10... I did a small check on the IgM data from the ISwR package (298 obs.) and found som

Re: [R] significance test interquartile ranges

2012-07-15 Thread Schaber , Jörg
not knowledgeable statistician enough to judge that. best, joerg Von: Prof Brian Ripley [rip...@stats.ox.ac.uk] Gesendet: Samstag, 14. Juli 2012 08:16 Bis: Greg Snow Cc: Schaber, Jörg; R-help Betreff: Re: [R] significance test interquartile ranges On 13

Re: [R] significance test interquartile ranges

2012-07-15 Thread Schaber , Jörg
Betreff: Re: [R] significance test interquartile ranges On Jul 14, 2012, at 08:16 , Prof Brian Ripley wrote: > On 13/07/2012 21:37, Greg Snow wrote: >> A permutation test may be appropriate: > > Yes, it may, but precisely which one is unclear. You are testing whether the > t

Re: [R] significance test interquartile ranges

2012-07-14 Thread Rui Barradas
Hello, Em 14-07-2012 13:08, peter dalgaard escreveu: On Jul 14, 2012, at 12:25 , Rui Barradas wrote: Hello, There's a test for iqr equality, of Westenberg (1948), that can be found on-line if one really looks. It starts creating a 1 sample pool from the two samples and computing the 1st an

Re: [R] significance test interquartile ranges

2012-07-14 Thread peter dalgaard
On Jul 14, 2012, at 12:25 , Rui Barradas wrote: > Hello, > > There's a test for iqr equality, of Westenberg (1948), that can be found > on-line if one really looks. It starts creating a 1 sample pool from the two > samples and computing the 1st and 3rd quartiles. Then a three column table > w

Re: [R] significance test interquartile ranges

2012-07-14 Thread Rui Barradas
Hello, There's a test for iqr equality, of Westenberg (1948), that can be found on-line if one really looks. It starts creating a 1 sample pool from the two samples and computing the 1st and 3rd quartiles. Then a three column table where the rows correspond to the samples is built. The middle

Re: [R] significance test interquartile ranges

2012-07-14 Thread peter dalgaard
On Jul 14, 2012, at 08:16 , Prof Brian Ripley wrote: > On 13/07/2012 21:37, Greg Snow wrote: >> A permutation test may be appropriate: > > Yes, it may, but precisely which one is unclear. You are testing whether the > two samples have an identical distribution, whereas I took the question to b

Re: [R] significance test interquartile ranges

2012-07-13 Thread Prof Brian Ripley
On 13/07/2012 21:37, Greg Snow wrote: A permutation test may be appropriate: Yes, it may, but precisely which one is unclear. You are testing whether the two samples have an identical distribution, whereas I took the question to be a test of differences in dispersion, with differences in lo

Re: [R] significance test interquartile ranges

2012-07-13 Thread Weidong Gu
Sorry, I meant Kolmogorov-Smirnov test. Thanks Peter for correction. Weidong On Fri, Jul 13, 2012 at 4:56 PM, Peter Ehlers wrote: > On 2012-07-13 13:33, Weidong Gu wrote: >> >> Hi Joerg, >> >> Seems Mann-Whitney-Wilcoxon test (ks.test in R) would do the work >> which tests differences anywhere

Re: [R] significance test interquartile ranges

2012-07-13 Thread Peter Ehlers
On 2012-07-13 13:33, Weidong Gu wrote: Hi Joerg, Seems Mann-Whitney-Wilcoxon test (ks.test in R) would do the work which tests differences anywhere in two distributions, e.g. tails, interquartiles and center. The ks.test() function refers to the Kolmogorov-Smirnov test, not the Wilcoxon test.

Re: [R] significance test interquartile ranges

2012-07-13 Thread Greg Snow
A permutation test may be appropriate: 1. compute the ratio of the 2 IQR values (or other comparison of interest) 2. combine the data from the 2 samples into 1 pool, then randomly split into 2 groups (matching sample sizes of original) and compute the ratio of the IQR values for the 2 new samples.

Re: [R] significance test interquartile ranges

2012-07-13 Thread Weidong Gu
Hi Joerg, Seems Mann-Whitney-Wilcoxon test (ks.test in R) would do the work which tests differences anywhere in two distributions, e.g. tails, interquartiles and center. Weidong Gu On Fri, Jul 13, 2012 at 7:32 AM, Schaber, Jörg wrote: > Hi, > > I have two non-normal distributions and use interq

[R] significance test interquartile ranges

2012-07-13 Thread Schaber , Jörg
Hi, I have two non-normal distributions and use interquartile ranges as a dispersion measure. Now I am looking for a test, which tests whether the interquartile ranges from the two distributions are significantly different. Any idea? Thanks, joerg [[alternative HTML version deleted]]

Re: [R] Significance test

2011-09-23 Thread setrofim
Yuta, Thanks for the response. Yuta wrote: > > You've got to state the problem little bit more clear. > > What do you mean by "set"? Is it a list of certain possible values, > available as outcomes of each single measurement (variate)? Or is it > something else? > How many variates do you have

Re: [R] Significance test

2011-09-23 Thread Yuta Tamberg
You've got to state the problem little bit more clear. What do you mean by "set"? Is it a list of certain possible values, available as outcomes of each single measurement (variate)? Or is it something else? How many variates do you have inside each sample? What is it exactly that you want to find

[R] Significance test

2011-09-23 Thread setrofim
I have a bunch of benchmark measurements that look something like this: sample.10.000.0625000.0583300.058330 0.058330 sample.20.0583300.0583300.0583300.058330 0.058330 sample.30.0625000.062500