Finding max value of a specific date awk

Question

I have a file with several rows and with each row containing the following data-

name 20150801|1 20150802|4  20150803|6  20150804|7  20150805|7  20150806|8  2015         


        

Answer 1

I think you mean this:

awk -v date=20150823 '{for(f=2;f<=NF;f++){split($f,a,"|");if(a[1]==date&&a[2]>max){max=a[2];name=$1}}}END{print name,max}' YourFile

So, you pass the date you are looking for in as a variable called date. You then iterate through all fields on the line, and split the date and value of each into an array using | as separator - a[1] has the date, a[2] has the value. If the date matches and the value is greater than any previously seen maximum, save this as the new maximum and save the first field from this line for printing at the end.

Answer 2

As a quick&dirty solution, we can perform this in following Unix commands:

yourdatafile=<yourdatafile>
yourdate=<yourdate>

cat $yourdatafile | sed 's/|/_/g' | awk -F "${yourdate}_" '{print $1" "$2}' | sed 's/[0-9]*_[0-9]*//g' | awk '{print $1" "$2}' |sort -k 2n | tail -n 1

With following sample data:

$ cat $yourdatafile
Alice 20150801|44 20150802|21  20150803|7  20150804|76  20150805|71
Bob 20150801|31 20150802|5 20150803|21 20150804|133 20150805|71

and yourdate=20150803 we get:

$ cat $yourdatafile | sed 's/|/_/g' | awk -F "${yourdate}_" '{print $1" "$2}' | sed 's/[0-9]*_[0-9]*//g' | awk '{print $1" "$2}' |sort -k 2n | tail -n 1
Bob 21

and for yourdate=20150802 we get:

$ cat $yourdatafile | sed 's/|/_/g' | awk -F "${yourdate}_" '{print $2" "$1}' | sed 's/[0-9]*_[0-9]*//g' | awk '{print $2" "$1}' | sort -k 2n | tail -n 1
Alice 21

The drawback is that only one line is printed the highest value of a day was achieved by more than one name as can be seen with:

$ yourdate=20150805; cat $yourdatafile | sed 's/|/_/g' | awk -F "${yourdate}_" '{print $2" "$1}' | sed 's/[0-9]*_[0-9]*//g' | awk '{print $2" "$1}' | sort -k 2n | tail -n 1
Bob 71

I hope that helps anyway.

Answer 3

You couldn't have taken 5 seconds to give your sample input different values? Anyway, this may work when run against input that actually has different values for the dates:

$ cat tst.awk
BEGIN { FS="[|[:space:]]+" }
FNR==1 {
    for (i=2;i<=NF;i+=2) {
        if ( $i==tgt ) {
            f = i+1
        }
    }
    max = $f
}
$f >= max { max=$f; name=$1 }
END { print name }

$ awk -v tgt=20150801 -f tst.awk file
name2