CODEWITHSUNDEEP
linuxawk
mcontoor
mcontoor

Reputation: 27

Awk - count the occurences of a value in a column

My aim is to run an awk code to check the value of column 4 and assign the count of its occurrence against it. My data looks like this 

DN  Area    Peri    FID DN2 Area2   Peri2   FID2  
1   70  39  1066    1   47  29  3  
1   70  39  1083    1   1142    262 11  
1   4662    465 1085    1   23  19  16  
1   4662    465 1085    1   47  29  9  
1   4662    465 1085    1   1142    262 11  
1   280 78  1087    1   513 126 18  
1   23  19  1093    1   47  29  12  
1   93  48  1094    1   93  48  19  
1   117 48  1100    1   466 136 17  
1   326 126 1131    1   723 223 54  
1   326 126 1131    1   513 126 18  
1   23  19  1135    1   723 136 32  
1   47  29  1138    1   1702    281 49  
1   187 87  1150    1   47  29  40  
1   23  19  1153    1   187 78  47  
1   2191    397 1156    1   23  19  24  
1   2191    397 1156    1   47  29  20  
1   2191    397 1156    1   5524    581 87  
1   256 87  1157    1   466 136 41

Expected outcome: 

1  
1  
3  
3 I
3  
1  
1  
1  
1  
2  
2  
1  
1  
1  
1  
3  
3  
3  
1

when I run the code I've written I get a '>' and the command doesnt stop running 

awk '{if ( FNR>1 && count[$4]=i ) { for(i=1; i<=NR; ++i) printf "%d\n", i}} file

Upvotes: 0

Views: 220

Answers (3)

kvantour
kvantour

Reputation: 26591

In a single pass you can do (with the assumption you do not want to count the header)

awk '{ a[NR]=$4; c[$4]++ }END{for(i=2;i<=NR;++i) print c[a[i]] }' file

Upvotes: 0

steffen
steffen

Reputation: 17058

Read the file twice: Count the occurences in the first run (NR==FNR) and print them out in the second run (FNR<NR).

awk 'FNR==NR{a[$4]++}FNR<NR{print a[$4]}' file file

This counting also includes the headline, skip it if you don't want it.

Upvotes: 1

RavinderSingh13
RavinderSingh13

Reputation: 133780

Could you please try following.

awk 'FNR==NR{a[$4]++;next} FNR!=NR && FNR>1{print $4,a[$4]}'  Input_file Input_file

Above will print 4th column and its occurrence value both, in case you need only occurrence value then remove $4 from print part in above code.

Upvotes: 1

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