UNIX for Dummies Questions & Answers

awk ' BEGIN {for (i=1; i<32; i++)
             {
             	min[i]=999
             	max[i]=-999
             } 
            }
      {
       	if( $5 < min[$3] ) { min[$3]=$5 }
       	if( $5 > max[$3] ) { max[$3]=$5 }
      }
      END {for(i in min) {if( min[i] < 999 ) {print i, min[i], max[i]} }
      }
     '  weather_01.dat  > 01minmax.dat

#!/bin/ksh
mkfile()
{
   awk ' BEGIN {for (i=1; i<32; i++)
             {
             	min[i]=999
             	max[i]=-999
             } 
            }
      {
       	if( $5 < min[$3] ) { min[$3]=$5 }
       	if( $5 > max[$3] ) { max[$3]=$5 }
      }
      END {for(i in min) {if( min[i] < 999 ) {print i, min[i], max[i]} }
      }
     '  "$1"  >  "$2"
     
}

for i in 01 02 03 04 05 06 07 08 09 10 11 12
do
    infile="weather_"$i".dat"
    outfile=$i"minmax.dat
    mkfile $infile $outfile
done

awk -F, 'NR==1 {min=$5;max=$5;d=$3;next}
d != $3 {print d, min, max;d=$3;max=$5;min=$5}
$5 > max{max=$5}
$5 < min{min=$5}
END{print d, min, max;d=$3}
' 01_weath.dat > 01minmax.txt