spark

spark.sh

#!/bin/bash -e

if [ "$1" ]
then
    data="$@"
else
    while read x
    do
        data="$data $x"
    done
fi

ticks=(▁ ▂ ▃ ▅ ▆ ▇)
sorted=$(echo "$data" |tr ' ' '\n' | sort -n)
sorted=($sorted)
data=($data)
incr=${sorted[0]}
i=${#sorted[@]}
mx=${sorted[$i - 1]}
i=${#ticks[@]}
width=$(( $mx / $i ))

for (( i = 0 ; i < ${#ticks[@]} ; ++i ))
do
    thres=$(( $i * $width + $incr ))
    bins="$bins $thres"
done

bins=($bins)

for n in ${data[@]}
do
    for (( i = ${#bins[@]} ; i > 0 ;  --i ))
    do
        thres=${bins[$i - 1]}
        hi=$(( $thres + $width ))
        if [ $n -gt $hi -o $n -ge $thres ]
        then
            echo -ne "${ticks[$i - 1]}"
            break
        fi
    done
done
echo