question about limma and gcrma
1
0
Entering edit mode
Hongqing Li ▴ 40
@hongqing-li-2339
Last seen 11.2 years ago
An embedded and charset-unspecified text was scrubbed... Name: not available Url: https://stat.ethz.ch/pipermail/bioconductor/attachments/20070822/ 71d129fa/attachment.pl
• 514 views
ADD COMMENT
0
Entering edit mode
@james-w-macdonald-5106
Last seen 11 hours ago
United States
Hi Hongqing, Hongqing Li wrote: > Hi, > > I have been using limma and gcrma for microarray analysis for a while. > recently I have to reinstall my system so I update my R from 2.4 to 2.5.1 > I don't know the version of limma,gcrma packages, but they were installed > as I install my old R 2.4. However, when I run the same script to analyze > the same file I did last year, I got different results for both gcrma and > limma. > Although the difference is not dramatic. I plotted the scatter plot for > gcrma > summarized expression data from old analysis and new analysis, it supposed > to be a straight line, but on my plot the low expression values form a > slightly > inflated data cloud around the diagonal line. For limma, only about 10 > really > large or really small t statistics are strongly different from the old > analysis. > Is this a known issue for using different version of packages ? Well, yes. Probably. Since you don't know what versions you were using, nor the versions you are now using, it is impossible to say for sure (plus you don't say how you are analyzing the data, nor do you give a small reproducible example that we could try ourselves). However, Both limma and gcrma tend to change (limma perhaps more than gcrma) over time, as the maintainers improve both the implementation and underlying statistical methodology, so it is not unlikely that you would get 'not dramatic' changes in results with different versions. Best, Jim > > Thanks, > Hongqing > > [[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 -- James W. MacDonald, M.S. Biostatistician Affymetrix and cDNA Microarray Core University of Michigan Cancer Center 1500 E. Medical Center Drive 7410 CCGC Ann Arbor MI 48109 734-647-5623
ADD COMMENT
0
Entering edit mode
An embedded and charset-unspecified text was scrubbed... Name: not available Url: https://stat.ethz.ch/pipermail/bioconductor/attachments/20070823/ 1e6415c0/attachment.pl
ADD REPLY
0
Entering edit mode
There are two ways to get version numbers. For a single package: packageDescription("thepackage")$Version For all loaded packages: sessionInfo() Best, Jim Hongqing Li wrote: > Hi James, > > The whole story is that my hard drive was broken and I only have backup > files left in csv files and scripts used to generate those files. But I did > not > put down the version number of R.gcrma,limma I used, neither could I > restore the old R working environment, so I have no way to check the > package. > versions. I think it is very important to add a line or two on my datafiles > with > the version numbers of those packages from now on. > > What I did was simple: > > data<-ReadAffy() > eset<-gcrma(data) > exprs2excel(eset,'somefilename') > > When I compare the results from this script and the old one, I can not find > perfect > agreement. I installed bioconductor 2.0 last week, so the package should be > Affy > 1.14.2, gcrma 2.8.1, limma 2.10.5. as I found out in > http://www.bioconductor.org/packages/2.0/bioc/ > > BTW, how do you print out the version number of a package in R? I googled > but > could not find the answer. > > Thanks, > hongqing > > On 8/23/07, James W. MacDonald <jmacdon at="" med.umich.edu=""> wrote: >> Hi Hongqing, >> >> Hongqing Li wrote: >>> Hi, >>> >>> I have been using limma and gcrma for microarray analysis for a while. >>> recently I have to reinstall my system so I update my R from 2.4 to >> 2.5.1 >>> I don't know the version of limma,gcrma packages, but they were >> installed >>> as I install my old R 2.4. However, when I run the same script to >> analyze >>> the same file I did last year, I got different results for both gcrma >> and >>> limma. >>> Although the difference is not dramatic. I plotted the scatter plot for >>> gcrma >>> summarized expression data from old analysis and new analysis, it >> supposed >>> to be a straight line, but on my plot the low expression values form a >>> slightly >>> inflated data cloud around the diagonal line. For limma, only about 10 >>> really >>> large or really small t statistics are strongly different from the old >>> analysis. >>> Is this a known issue for using different version of packages ? >> Well, yes. Probably. Since you don't know what versions you were using, >> nor the versions you are now using, it is impossible to say for sure >> (plus you don't say how you are analyzing the data, nor do you give a >> small reproducible example that we could try ourselves). >> >> However, Both limma and gcrma tend to change (limma perhaps more than >> gcrma) over time, as the maintainers improve both the implementation and >> underlying statistical methodology, so it is not unlikely that you would >> get 'not dramatic' changes in results with different versions. >> >> Best, >> >> Jim >>> Thanks, >>> Hongqing >>> >>> [[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 >> >> -- >> James W. MacDonald, M.S. >> Biostatistician >> Affymetrix and cDNA Microarray Core >> University of Michigan Cancer Center >> 1500 E. Medical Center Drive >> 7410 CCGC >> Ann Arbor MI 48109 >> 734-647-5623 >> > > [[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 -- James W. MacDonald, M.S. Biostatistician Affymetrix and cDNA Microarray Core University of Michigan Cancer Center 1500 E. Medical Center Drive 7410 CCGC Ann Arbor MI 48109 734-647-5623
ADD REPLY

Login before adding your answer.

Traffic: 747 users visited in the last hour
Help About
FAQ
Access RSS
API
Stats

Use of this site constitutes acceptance of our User Agreement and Privacy Policy.

Powered by the version 2.3.6