summary

#!/bin/bash
#The MIT License (MIT)
#
#Copyright (c) 2015 Tommaso Leonardi, tleonardi@gmail.com
#
#Permission is hereby granted, free of charge, to any person obtaining a copy
#of this software and associated documentation files (the "Software"), to deal
#in the Software without restriction, including without limitation the rights
#to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
#copies of the Software, and to permit persons to whom the Software is
#furnished to do so, subject to the following conditions:
#
#The above copyright notice and this permission notice shall be included in all
#copies or substantial portions of the Software.
#
#THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
#IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
#FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
#AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
#LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
#OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
#SOFTWARE.
#

usage()
{
cat <<EOF

Usage: $(basename "$0") [-h] [-c column] filename

This script prints min, max and quartiles of the values in the
specified column.
The quantiles algorithm is the linear interpolation of the modes
for the order statistics for the uniform distribution on [0,1].
Same as quantile(type=7) in R.

  -h		Print this help screen
  -c <1>	Column
  -m <1024>	Size of sort buffer (in MB)
EOF
}


ARGS=$(getopt -o "hc:" -n "dist.sh" -- "$@")

if [ $? -ne 0 ]; then
    usage
    exit 1;
fi

eval set -- "$ARGS"

# Now go through all the options
while true; do
    case "$1" in
        -h)
                usage
		exit 1
                ;;
	-c)
		if [[ -n "$2" ]]; then
			COL=$2
			shift 2
		else exit 1
		fi
		;;
	-m)
                if [[ -n "$2" ]]; then
                        MEM=$2
                        shift 2
                else exit 1
                fi
                ;;
	\?)
      		echo "Invalid option: -$OPTARG" >&2
      		exit 1
      		;;
        --) shift ; break;;
    esac
done



fifo=$(mktemp -u)


if [[ ! -a $fifo ]]; then
	mkfifo $fifo
	trap "rm -f $fifo" EXIT
else
	echo "Can't create fifo: $fifo"
	exit 1
fi

if [[ -n "$1" ]]; then
	# FILE provided
	FILE=$1
	if [[ ! -f $FILE ]]; then
		echo "$FILE: no such file";
		exit 1;
	fi
	exec < $FILE
fi

if [[ -z $COL ]]; then
	COL=1
fi

if [[ -z $MEM ]]; then
	        MEM=1024
fi

cut -f$COL <&0 | tee >(wc -l>$fifo) | sort -S $MEM -k1,1n | awk -v C=$(cat $fifo) '
BEGIN{print "n="C}
{
tot+=$1
if(NR==1){printf("Min: %.4f\n",$1)}; 
if(NR==C){printf("Max: %.4f\n",$1)};
for(p=0.25; p<1; p+=0.25){
	h=((C-1)*p)+1
	if(NR==int(h)) { xh=$1}
	if(NR==int(h)+1){
		if(h % 1 == 0){ printf("%.2f: %.4f\n",p,xh)}
		else {printf("%.2f: %.4f\n",p,xh + (h - int(h)) * ($1 - xh))}
	}
}
}
END{print "Mean: "tot/NR}
'