,

,

df[] <- lapply(df, function(i)as.numeric(gsub(',', '.', i)))
do.call(cbind, lapply(split.default(df, gsub('\D+', '', names(df))), function(i) i[2] / i[1]))
#   SAMPLE1.AD SAMPLE2.AD
#1 1.000000000   1.000000
#2 0.004066052   0.001000
#3 0.004117005   1.000000
#4 0.499803347   0.496687