taxonMedian

Computes median values of variables for each taxon in a matrix containing multiple specimens of multiple taxa. Copy and paste the following function into the R Console and hit enter. Afterwards, you can run the function by typing "taxonMedian(x)" where "x" is the m by n matrix of m specimens and n-1 variables (the first column must be a vector of taxon names/classifiers).

taxonMedian <- function(x){

M <- matrix(nrow=length(unique(x[,1])),ncol=length(x[1,-1]))

for (i in 1:length(unique(x[,1]))){

sp <- x[x[,1]==unique(x[,1])[i],-1]

med.sp <- matrix(nrow=1,ncol=length(x[1,-1]))

for (j in 1:length(x[1,-1])){

med.sp[,j] <- median(sp[,j],na.rm=T)

}

M[i,] <- med.sp

}

rownames(M) <- unique(x[,1])

colnames(M) <- colnames(x[,-1])

M <- data.frame(M)

return(M)

}

##### Function by Manabu Sakamoto, 2012: manabu.sakamoto@gmail.com