r - Basic Loop through a matrix with pasting column names into result objects

Question

I have a dataframe (samples x species) which I want to loop this command through (column-wise):

dist <- vegdist(decostand(X,"standardize",MARGIN=2), method="euclidean")

I need the name of the column in each of the new dist-values. So if my columns are called A, B, C, then the result should be dist-values called Dist.A, Dist.B, Dist.C, and so on. I believe this can be done with paste, but I have no clue how.

Answer 1

You can try (if it is a data.frame)

 d1[] <- lapply(colnames(d1), function(x) paste(d1[,x], x, sep="."))

Or

 d1[] <- Map(function(x,y) paste(x, y, sep="."), d1, colnames(d1))

If it is a matrix

  m1[] <- paste(m1, colnames(m1)[col(m1)],sep=".")

data

 m1 <- matrix(1:15, ncol=3, dimnames=list(NULL, LETTERS[1:3]))
 d1 <- as.data.frame(m1)