Shell Programming and Scripting

#! /usr/bin/awk -f

## Output in a nice format:
## count,min,max,sum,mean,stddev,pop_stddev

BEGIN   {
        OFS = ","
        }

#       Main section...
#       The count is simply NR
        {
        if ( min !~ "[0-9]" )
                {
                min = $1
                }

        if ( $1 < min )
                {
                min = $1
                }

        if ( $1 >= max )
                {
                max = $1
                }

        sum += $1
        delta = $1 - mean
        mean += delta / NR
        meansqr += delta * ( $1 - mean )
        }

END     {
        std_dev = sqrt( meansqr / NR )
        if ( NR > 1 )
                {
                pstd_dev = sqrt( meansqr / ( NR - 1 ) )
                }
        else
                {
                pstd_dev = 0
                }

#       printf("%d,%d,%d,%d,%d,%d,%d\n",FNR,min,max,sum,mean,std_dev,pstd_dev)
        print FNR,min,max,sum,mean,std_dev,pstd_dev
        }

15,2048,12582912,27329844,1.82199e+06,3.47817e+06,3.60025e+06
2,16384,20480,36864,18432,2048,2896.31
1,12288,12288,12288,12288,0,0
11,12288,116391936,184591770,1.67811e+07,3.27268e+07,3.43241e+07