Select column and row values with an index in data frame


This question already has an answer here:


Since you have your indices in ind one way could be to use mapply:

#the first argument is the function call 
#second argument is your matrix coerced to data.frame
#third argument is your indices
#each time an index will be used in conjunction to a column
#and you get your result
mapply(function(x,y) x[y],, ind)
#       LO3         Tx         Gh         RH         SR 
# 0.4282915  0.4863608 -0.4962140 -0.8023141 -0.8023141 

This can do it for you:

mapply(function(i,j) sample[i,j], seq_len(ncol(sample)), ind)

> mapply(function(i,j) sample[i,j], seq_len(ncol(sample)), ind)
[1]  0.4282915  0.4863608 -0.4962140 -0.8023141 -0.8023141

if you want you can set the names of the result from ind

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