hi, I am working with an expression matrix, I think I will use ratios for analysis of 2 conditions, does anyone know how to change values in a matrix. if I have 3 in log2 => 2^3=8 in decimal, how I do that in R for an entire vector or matrix? Thanks

D.Enrique ESCOBAR ESPINOZA wrote: > hi, > I am working with an expression matrix, > I think I will use ratios for analysis of 2 conditions, > does anyone know how to change values in a matrix. > > if I have 3 in log2 => 2^3=8 in decimal, > how I do that in R for an entire vector or matrix? Did you try the obvious? > x <- 1:5 > 2^x [1] 2 4 8 16 32 > y <- matrix(rep(1:5, 5), ncol=5) > 2^y [,1] [,2] [,3] [,4] [,5] [1,] 2 2 2 2 2 [2,] 4 4 4 4 4 [3,] 8 8 8 8 8 [4,] 16 16 16 16 16 [5,] 32 32 32 32 32 Best, Jim > Thanks > > _______________________________________________ > 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 ********************************************************** Electronic Mail is not secure, may not be read every day, and should not be used for urgent or sensitive issues.

vec = 1:10 mat = matrix(1:10, ncol=2) 2^vec 2^mat b On Jun 15, 2007, at 1:08 PM, D.Enrique ESCOBAR ESPINOZA wrote: > hi, > I am working with an expression matrix, > I think I will use ratios for analysis of 2 conditions, > does anyone know how to change values in a matrix. > > if I have 3 in log2 => 2^3=8 in decimal, > how I do that in R for an entire vector or matrix? > Thanks