Transpose a matrix with perl nested map

Here’s the matrix that we’ll be using:

$ paste <(seq 1 5) <(seq 12 16) 
1	12
2	13
3	14
4	15
5	16

Now, let’s use a perl one-liner with nested maps to transpose the matrix:

$ paste <(seq 1 5) <(seq 12 16) | perl -ane 'push @matrix,[@F]; END { print join "\n",map {$row=$_; join"\t",map { $matrix[$_][$row]} 0 .. $#matrix } 0 .. $#{$matrix[0]}; print "\n" }'
1	2	3	4	5
12	13	14	15	16

I got the idea from this blog post, but I slightly modified it so that you don’t need to make a copy of the transposed array (to save memory)