CODEWITHSUNDEEP
arraysr
user1723765
user1723765

Reputation: 6409

Select values in array that satisfy another condition

Let's say I have an array of the following form:

,,1

    [,1] [,2] [,3]
[1,] 34   3     9
[2,] 45   5     8
.
.
,,2
    [,1] [,2] [,3]
[1,] 21   5    10
[2,] 94   2    10
.
.

First I want to select the highest value in the third column of each matrix:

apply(array[,3,],2,max)

This returns a vector with the highest element in each matrix.

Now I would like to select those values in the second column [,2] of each matrix which have the max value in the third column [,3].

How can I do this?

From the example above the desired output would be:

,,1

   3
,,2

   5,2

Upvotes: 0

Views: 162

Answers (1)

akrun
akrun

Reputation: 887481

You may try

lapply(1:dim(arr1)[3], function(i) {
         x1 <- arr1[,,i]
         x1[,2][x1[,3]==max(x1[,3])]})
#[[1]]
#[1] 3

#[[2]]
#[1] 5 2

Upvotes: 1

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