r - How to find all the matches in a table? -

this question has answer here:

i know function

match(x, dataset)

but shows first position of match found , need specify column in table in order result. if there's table this

   x1  x2   ... 1   3   1   ... 2   4   2   ... 3   1   1   ... 4   2   4   ...

how can find position of number 1s? want row , column number separately. result of above example should 1,3(row) , x1,x2(column).

dat == 1 give matrix positions equal 1 true otherwise false.

additionally, can find row , column positions of elements meet condition (in case, equal 1 istrue), using which , arr.ind argument.

your data

dat <- read.table(header=true, text=   "x1  x2    1   3   1    2   4   2    3   1   1    4   2   4 ")

extract positions data equals one

which(dat==1, arr.ind=true) #   row col # 3   3   1 # 1   1   2 # 3   3   2

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