Question

i have data frame like this :

   1   2   3   4   5   
1 0.1 0.2 0.5 0.4 0.8
2 0.6 0.8 0.4 0.7 0.2
3 0.6 0.1 1.8 0.7 0.2
4 0.6 0.7 0.4 0.6 0.1

Now , i want to search for the number 0.8 only in first two rows in column no. 5 and 0.2 in rows 3 and 4 in tha same column.

and i have 2000 rows and ofcourse can not do it manually.

Is there a way to do it in R?

Answer 1

Your question is very unclear.

If you want the position of the .8, this will do:

  d <- matrix(round(runif(50),1), nc=5)
  which(d == .8, arr.ind=TRUE)

If you want those with two .2 just below, in the same column,
you can use:

  # Shift the array
  d1 <- rbind(  d[-1,], rep(0,ncol(d) ) )
  d2 <- rbind( d1[-1,], rep(0,ncol(d1)) )
  which( d == .8 & d1 == .2 & d2 == .2, arr.ind=TRUE )