frequency of occurence

Question

I have a tab-delimited text file, that is around 3K lines long.

I want to calculate frequency of data appearing in it, in 10,000 ranges.

Input.txt

Price  
500    
1500   
10001   
15000  
17000  
25000  
33000  
39000  
:
:
8000000 

Output.txt

Pricerange      pricerangecount  
0-10000          2               
10000-20000      3               
20000-30000      1               
30000-40000      2 
:
:  

Answer 1

awk 'BEGIN{print "Pricerange\tpricerangecount"}
     NR>1 {cur=int($0/10000); A[cur]+=1; if (cur>m) m=cur; }
     END {for(i=0;i<=m;i++) printf("%d-%d:\t%d\n",i*10000, (i+1)*10000, A[i])}' 

Answer 2

I generally use gsl-histogram from the GNU Scientific Library package. As one-liner as it gets in your case (without pretty-printing, the previous solutions are all right, and I have upvoted them):

  tail -n+2 Input.txt | gsl-histogram 0 40000 4

Answer 3

Perl:

perl -ne'$h{int$_/10000}++;END{printf"%d0000-%d0000  %d\n",$_,$_+1,$h{$_}for sort{$a<=>$b}keys%h}'

expanded:

while(<>) { #read each line (-n)
  $h{int $_/10000}++; #count buckets
}
for (sort {$a<=>$b} keys %h) { #sort numerically
  printf "%d0000-%d0000  %d\n", $_, $_+1, $h{$_};
}

Answer 4

Here's a coreutils and dc alternative:

<Input.txt tail -n +2 | while read; do <<< "$REPLY 10000 /p" | dc; done | sort -n | uniq -c \
   | while read cnt rng; do 
       printf "%-15s %-15s\n" \
         $(<<< "$rng 10000 *p" | dc)-$(<<< "$rng 1 + 10000 *p" | dc) $cnt
     done > Output.txt

Output.txt:

0-10000         2
10000-20000     3
20000-30000     1
30000-40000     2

Answer 5

Although bash is not a good solution, following a comment, here another solution

N=10000
while read n;do [[ $n =~ ^[0-9]*$ ]]&&((a[n/N]++));done
for i in ${!a[*]};do echo $((i*N))-$(((i+1)*N-1)) $((a[i]));done

it will be faster on small files because there isn't the overhead of spawning a new process but less efficient on large files.