by Nikhil

Categories

  • Build & Release

Tags

  • UNIX
  • awk
  • matrices

Matrices Sum using awk

Below program can provide sum of any number of matrices of any degree.

  •  Here, I am adding 3 matrices.
  • Each matrix is stored in a file: 1 row in every line and columns are space separated.
  • Each matrix is of 3x3. You can use it for matrix of any degree and it is not neessary that all the matrices will be of same degree 1.e. first one can be of 3x3, second one can be of 3x4 and so on.

 

Below 3 files are containing row and column of each matrix.

$ cat f1 1 1 1 1 1 1 1 1 1 $ cat f2 2 2 2 2 2 2 2 2 2 $ cat f3 3 3 3 3 3 3 3 3 3 $ awk '{for (i=1;i\<=NF;i++) { arr[FNR,i] = arr[FNR,i] + $i; if(k \< NF){k=NF} } } END { print "Matrix Sum:"; for(i=1;i\<=FNR;i++) { for(j=1;j\<=k;j++) { printf "%s ", arr[i,j] } print ""}}' f1 f2 f3 Matrix Sum: 6 6 6 6 6 6 6 6 6

 

Note: awk reads line by line

Here:

NF : Number of fields in cureent line which awk is reading

FNR : Line number of the current line being read of the file

arr : 2 dimensional array which will store the final sum of the matrices stored in file f1, f2 and f3

 

Please feel free to contact in case of any doubt, suggestion.