I'd probably start with ?dist Sarah
On Thu, Sep 4, 2014 at 4:10 PM, Ding, Yuan Chun <ycd...@coh.org> wrote: > > > > I want to calculate Euclidean distance between 12 populations, in each > population there are 20 samples and each sample is measured for 100 genes > (these are microarray data; the numbers here are just examples). > The equation I found is: > distance = sqrt{[sum(Average of xi -average of yi)^2] /n }, i=1 to n; > where xi and yi are the expression of gene i over two populations with p and > q samples (x1, x2,...,xp), (y1, y2,...,yq), n is the number of genes. > part of data are pasted below > row.names pop1.1 pop1.2 pop1.3 pop1.4 pop2.1 pop2.2 pop2.3 pop2.4 > 7A5 5.38194 4.06191 4.88044 5.60383 6.23101 6.53738 4.80336 5.86136 > A1BG 5.15155 4.29441 4.59131 4.90026 4.62908 4.48712 4.73039 4.46208 > A1CF 4.22396 4.14451 4.41465 3.93179 4.89638 4.66109 4.20918 4.48107 > A26C3 12.1969 12.4179 10.9786 11.7659 11.405 11.7594 11.1757 11.8128 > How might one calculate these distances in R with this data structure? > > > Thanks, > > Ding > -- Sarah Goslee http://www.functionaldiversity.org ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.