Finding the maximum absolute value whilst preserving + or - symbol
matrix, r
Solution
You need the index of the value in the matrix which is the maximum absolute value, which you can then use to return the value itself. `which.max` will do this (and `which.min` for the opposite):
mat[which.max( abs(mat) )]
# [1] -30
Problem
If I have a matrix: ``` mat=matrix(c(-21,14,28,17,-16,-9,-17,-30,18), nrow=3) mat [,1] [,2] [,3] [1,] -21 17 17 [2,] 14 -16 -30 [3,] 28 -9 18 ``` I can isolate the highest absolute value simply with ``` max(abs(mat)) ``` However how do I preserve the sign so I return -30? For some context, I have a large number of matrices and I need a command to isolate the highest absolute number in all of them including the sign (some will be positive others negative). Thanks in advance!