I think you need to explain whether ABCDE are measured on the same individuals or are independent measurements. Naomi At 05:22 AM 8/24/2010, Weibo Xie wrote: >Yes, you catch my thought completely. A solution I used is to enumerate all >combination of A, B and C to obtain all possible values of (A-B)/(A-C) and >also enumerate all combination of D and E to get all possible D/E, then >apply Wilcoxon-Mann-Whitney rank test to compare these two groups of values. >By this method, if the lengths of A,B,..,E are 5, then we will have >5x5x5=125 values of (A-B)/(A-C) and 5x5=25 values of D/E. Such >enumerated data may inflate the sample size and make the test more >significant than the true. I don't know does it reasonable? > >-Weibo > > > >On Tue, Aug 24, 2010 at 4:41 PM, Moshe Olshansky <m_olshansky at="" yahoo.com="">wrote: > > > Do you mean that A,B,...,E are same length and you want to apply t-test to > > compare > > (A-B)/(A-C) to D/E? > > Technically this is straightforward, but even if A,B,...,E are normally > > distributed, this is very much not true for (A-B)/(A-C) and D/E, > so it won't > > be appropriate to apply t-test (uness A,C and E are constants). > > > > > > --- On *Tue, 24/8/10, Weibo Xie <xwbmail at="" gmail.com="">* wrote: > > > > > > From: Weibo Xie <xwbmail at="" gmail.com=""> > > Subject: Re: [BioC] Five variables, ABCDE, how to check whether (A-B)/(A-C) > > is equal to D/E? > > To: "Moshe Olshansky" <m_olshansky at="" yahoo.com=""> > > Cc: "Bioconductor" <bioconductor at="" stat.math.ethz.ch=""> > > Received: Tuesday, 24 August, 2010, 6:09 PM > > > > > > > > Thanks for your quick reply! I think it's like 'equal means' in Two-Sample > > t-Test. > > > > -Weibo > > > > On Tue, Aug 24, 2010 at 3:58 PM, Moshe Olshansky > <m_olshansky at="" yahoo.com<http:="" mc="" compose?to="m_olshansky" at="" yahoo.com=""> > > > wrote: > > > > What exactly do you mean by "equal"? > > > > --- On Tue, 24/8/10, Weibo Xie > <xwbmail at="" gmail.com<http:="" mc="" compose?to="xwbmail" at="" gmail.com="">> > > wrote: > > > > > From: Weibo Xie > <xwbmail at="" gmail.com<http:="" mc="" compose?to="xwbmail" at="" gmail.com=""> > > > > > > Subject: [BioC] Five variables, ABCDE, how to check whether (A-B)/(A-C) > > is equal to D/E? > > > To: "Bioconductor" > <bioconductor at="" stat.math.ethz.ch<http:="" mc="" compose?to="bioconductor" at="" stat.math.ethz.ch=""> > > > > > > Received: Tuesday, 24 August, 2010, 5:45 PM > > > Hello everyone, > > > > > > I have 5 variables, denoted as A to E, each with several > > > replicates. Is > > > there a reasonable statistical test to check whether > > > (A-B)/(A-C) is equal to > > > D/E? > > > > > > Thanks for your help, > > > > > > -Weibo > > > > > > [[alternative HTML version deleted]] > > > > > > _______________________________________________ > > > Bioconductor mailing list > > > > Bioconductor at stat.math.ethz.ch<http: mc="" compose?to="Bioconductor" at="" stat.math.ethz.ch=""> > > > https://stat.ethz.ch/mailman/listinfo/bioconductor > > > Search the archives: > > http://news.gmane.org/gmane.science.biology.informatics.conductor > > > > > > > > > > > [[alternative HTML version deleted]] > >_______________________________________________ >Bioconductor mailing list >Bioconductor at stat.math.ethz.ch >https://stat.ethz.ch/mailman/listinfo/bioconductor >Search the archives: >http://news.gmane.org/gmane.science.biology.informatics.conductor Naomi S. Altman 814-865-3791 (voice) Associate Professor Dept. of Statistics 814-863-7114 (fax) Penn State University 814-865-1348 (Statistics) University Park, PA 16802-2111

Hi Naomi, Sorry for the confusion. The A-E were measured independently from five groups of samples. Thank you very much for clearing the statement. --Weibo On Tue, Aug 24, 2010 at 10:30 PM, Naomi Altman <naomi@stat.psu.edu> wrote: > I think you need to explain whether ABCDE are measured on the same > individuals or are independent measurements. > > Naomi > > > At 05:22 AM 8/24/2010, Weibo Xie wrote: > >> Yes, you catch my thought completely. A solution I used is to enumerate >> all >> combination of A, B and C to obtain all possible values of (A-B)/(A-C) and >> also enumerate all combination of D and E to get all possible D/E, then >> apply Wilcoxon-Mann-Whitney rank test to compare these two groups of >> values. >> By this method, if the lengths of A,B,..,E are 5, then we will have >> 5x5x5=125 values of (A-B)/(A-C) and 5x5=25 values of D/E. Such >> enumerated data may inflate the sample size and make the test more >> significant than the true. I don't know does it reasonable? >> >> -Weibo >> >> >> >> On Tue, Aug 24, 2010 at 4:41 PM, Moshe Olshansky <m_olshansky@yahoo.com>> >wrote: >> >> > Do you mean that A,B,...,E are same length and you want to apply t-test >> to >> > compare >> > (A-B)/(A-C) to D/E? >> > Technically this is straightforward, but even if A,B,...,E are normally >> > distributed, this is very much not true for (A-B)/(A-C) and D/E, so it >> won't >> > be appropriate to apply t-test (uness A,C and E are constants). >> > >> > >> > --- On *Tue, 24/8/10, Weibo Xie <xwbmail@gmail.com>* wrote: >> > >> > >> > From: Weibo Xie <xwbmail@gmail.com> >> > Subject: Re: [BioC] Five variables, ABCDE, how to check whether >> (A-B)/(A-C) >> > is equal to D/E? >> > To: "Moshe Olshansky" <m_olshansky@yahoo.com> >> > Cc: "Bioconductor" <bioconductor@stat.math.ethz.ch> >> > Received: Tuesday, 24 August, 2010, 6:09 PM >> > >> > >> > >> > Thanks for your quick reply! I think it's like 'equal means' in >> Two-Sample >> > t-Test. >> > >> > -Weibo >> > >> > On Tue, Aug 24, 2010 at 3:58 PM, Moshe Olshansky <m_olshansky@yahoo.com>> <http: mc="" compose?to="m_olshansky@yahoo.com"> >> >> > > wrote: >> > >> > What exactly do you mean by "equal"? >> > >> > --- On Tue, 24/8/10, Weibo Xie <xwbmail@gmail.com<>> http://mc/compose?to=xwbmail@gmail.com>> >> > wrote: >> > >> > > From: Weibo Xie <xwbmail@gmail.com<>> http://mc/compose?to=xwbmail@gmail.com> >> >> > > >> > > Subject: [BioC] Five variables, ABCDE, how to check whether >> (A-B)/(A-C) >> > is equal to D/E? >> > > To: "Bioconductor" <bioconductor@stat.math.ethz.ch<>> http://mc/compose?to=bioconductor@stat.math.ethz.ch> >> >> > > >> > > Received: Tuesday, 24 August, 2010, 5:45 PM >> > > Hello everyone, >> > > >> > > I have 5 variables, denoted as A to E, each with several >> > > replicates. Is >> > > there a reasonable statistical test to check whether >> > > (A-B)/(A-C) is equal to >> > > D/E? >> > > >> > > Thanks for your help, >> > > >> > > -Weibo >> > > >> > > [[alternative HTML version deleted]] >> > > >> > > _______________________________________________ >> > > Bioconductor mailing list >> > > Bioconductor@stat.math.ethz.ch< >> http://mc/compose?to=Bioconductor@stat.math.ethz.ch> >> >> > > https://stat.ethz.ch/mailman/listinfo/bioconductor >> > > Search the archives: >> > http://news.gmane.org/gmane.science.biology.informatics.conductor >> > > >> > >> > >> > >> >> [[alternative HTML version deleted]] >> >> _______________________________________________ >> Bioconductor mailing list >> Bioconductor@stat.math.ethz.ch >> https://stat.ethz.ch/mailman/listinfo/bioconductor >> Search the archives: >> http://news.gmane.org/gmane.science.biology.informatics.conductor >> > > Naomi S. Altman 814-865-3791 (voice) > Associate Professor > Dept. of Statistics 814-863-7114 (fax) > Penn State University 814-865-1348 (Statistics) > University Park, PA 16802-2111 > > [[alternative HTML version deleted]]