[BioC] Most stable gene pairs in array experiment

[David martin]

Hi,
I have the following matrix with normalized log2 values:
CondA    CondB    CondC    CondD    CondE
geneA    -6.19    -5.74    -5.82    -5    -5.59
geneB    -6.33    -5.32    -5.6    -4.88    -5.39
geneC    -6.15    -6.07    -5.6    -4.88    -5.9
geneD    -6.57    -6.11    -6.36    -5.36    -5.96
geneD    -6.74    -6.2    -5.49    -5.35    -5.95
geneE    -6.75    -6.24    -5.73    -5.63    -6.02


Created as follows:
geneA<-c(-6.19,   -5.74,   -5.82,   -5,  -5.59)
geneB<-c(-6.33,   -5.32,   -5.6,    -4.88,   -5.39)
geneC<-c(-6.15, -6.07, -5.6, -4.88, -5.9)
geneD<-c(-6.57,   -6.11,   -6.36,   -5.36,   -5.96)
geneD<-c(-6.74,   -6.2,    -5.49,   -5.35,   -5.95)
geneE<-c(-6.75,   -6.24,   -5.73,   -5.63,   -6.02)

mygenes<-rbind(geneA, geneB, geneC, geneD, geneE)
colnames(mygenes)<-c("CondA",   "CondB",   "CondC",   "CondD",
"CondE")

I'm looking for most stable pair genes across conditions. I'm not 
looking for individual gene variance but really for most stable pairs 
ratios.
For e.g What is the variance of geneA vs geneB across all conditions. 
What is the most stable pair ?

Any help would be appreciated.

david