How to sum numbers located in 2D array file using bash

Question

I have a file that contains data like this:

       column1  column2 column3
  row1  a(1,1)   a(1,2)  a(1,3)
  row2  a(2,1)   a(2,2)  a(2,3)
  row3  a(3,1)   a(3,2)  a(3,3)
  row4  a(4,1)   a(4,2)  a(4,3)


       column4  column5 column6
  row1  b(1,1)   b(1,2)  b(1,3)
  row2  b(2,1)   b(2,2)  b(2,3)
  row3  b(3,1)   b(3,2)  b(3,3)
  row4  b(4,1)   b(4,2)  b(4,3)

I need to sum the elements of the array to show an output like this the output

 column1    a(1,1)+a(2,1)       a(3,1)+a(4,1)  
 column2    a(1,2)+a(2,2)       a(3,2)+a(4,2)
 column3    a(1,3)+a(2,3)       a(3,3)+a(4,3)
 column4    b(1,1)+b(2,1)       b(3,1)+b(4,1)
 column5    b(1,2)+b(2,2)       b(3,2)+b(4,2)
 column6    b(1,3)+b(2,3)       b(3,3)+b(4,3)

I though that a way to do this is to specify the position of each number and them sum , but I have no idea how to do that.

In future, please do not cross-post questions (unix.stackexchange.com/questions/286568/…). For more information, see here. — Matt
– Matt, Commented Jun 13, 2016 at 20:14

karakfa · Accepted Answer · 2016-05-25 14:21:22Z

1

dance of the pipes

$ sed 's/row[0-9]//;/^$/d' filenums | 
  pr -2t | 
  awk 'NR==1{$1=$1; print; next} 
     !(NR%2){split($0,a); next}          
            {for(i=1;i<=NF;i++) $i+=a[i]}1' | 
  tr ' ' '\n' | 
  pr -3t

column1                 32                      72
column2                 34                      74
column3                 36                      76
column4                 32                      72
column5                 34                      74
column6                 36                      76

to compute the sums I replaced cell indices with values with this

$ tr -d 'ab(,)' < file > filenums

so a(1,1) became 11, etc.

answered May 25, 2016 at 14:21

karakfa

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5 Comments

alloppp Over a year ago

One question, in the example was considered two matrices, one after the other. How can I do the same with more than two matrices, what change need to be done to the script. Thanks in advance

karakfa Over a year ago

this is probably not the best approach for that case. I would suggest using awk's record structure with setting RS= and FS='\n' and handling headers with $1 and the data rows with even/odd fields similar to what I did with NR. Perhaps you should create a new question for that.

alloppp Over a year ago

Karakfa, I created a new question in unix.stackexchange.com/questions/286568/… see it friend

alloppp Over a year ago

Dear Karakfa, I solve the problem and the solution is in the previous link that I send you. But now I have a question to askyou.What if the numbers are real(not only integers), what change I need to do

karakfa Over a year ago

Doesn't matter, awk can handle it either way. I think you posted on a different channel.

Yordan Boikov · Accepted Answer · 2016-05-25 14:41:00Z

1

You can create multidimensional array something like this

awk 'BEGIN{i=0}{i++;r[i][0];split($0,r[i]," ");}END{print r[1][1]+r[2][1] #do your math here}' filename

answered May 25, 2016 at 14:41

Yordan Boikov

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