I have a file with the following data-
Input-
A B C D E F
A B B B B B
C A C D E F
A B D E F A
A A A A A F
A B C B B B
If any of the other rows starting from row 2 have the same letter as row 1, they should be changed to 1. Basically, I'm trying to find out how similar any of the rows are to the first row.
Desired Output-
1 1 1 1 1 1
1 1 B B B B
C A 1 1 1 1
1 1 D E F A
1 A A A A 1
1 1 1 B B B
The first row has become all 1 since it is identical to itself (obviously). In the second row, the first and second columns are identical to the first row (A B
) and hence they become 1 1
. And so on for the other rows.
I have written the following code which does this transformation-
for seq in {1..1} ; #Iterate over the rows (in this case just row 1)
do
for position in {1..6} ; #Iterate over the columns
do
#Define the letter in the first row with which I'm comparing the rest of the rows
aa=$(awk -v pos=$position -v line=$seq 'NR == line {print $pos}' f)
#If it matches, gsub it to 1
awk -v var=$aa -v pos=$position '{gsub (var, "1", $pos)} 1' f > temp
#Save this intermediate file and now act on this
mv temp f
done
done
As you can imagine, this is really slow because that nested loop is expensive. My real data is a 60x10000 matrix and it takes about 2 hours for this program to run on that.
I was hoping you could help me get rid of the inner loop so that I can do all 6 gsubs in a single step. Maybe putting them in an array of their own? My awk
skills aren't that great yet.
Input
Desired o/p
Explanation
FNR==1{ .. }
When
awk
reads first record of current file, do things inside bracessplit($0,a)
for(i=1;i<=NF;i++)
if (a[i]==$i) $i=1
Now we modified column value next just print modified row
}1
1
always evaluates to true, it performs default operation{print $0}
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