#!/usr/bin/awk -f

# supply max_lines and max as variables like this:
# cat /usr/share/dict/words | awk '{print length($1)}' | distribution -v max_lines=5 -v max=10

BEGIN {
        LIMIT=max
        DEFAULT_MAX_LINES=55
        if (lines) {
                NUMBER_OF_LINES=lines
        }
        else {
                NUMBER_OF_LINES=55
        }
        if (max_width) {
                LINE_WIDTH=max_width
        }
        else {
                LINE_WIDTH=100
        }
}
{
        if (match($1,/^[0-9\.]+$/)){
                if(!LIMIT>0 || $1<LIMIT) {
                        values[i++]=$1
                }
        }
}
END {
        number_of_records = 0
        for(v_index in values) {
                if(max<values[v_index]) max = values[v_index]
                number_of_records++
        }
        if (max_lines) {
                if (max <= max_lines) {
                        number_of_lines = max
                }
                else {
                        number_of_lines = max_lines
                }
        }
        else {
                if (max <= DEFAULT_MAX_LINES) {
                        number_of_lines = max
                }
                else {
                        number_of_lines = DEFAULT_MAX_LINES
                }
        }
        line_height=max/number_of_lines
        for(v_index in values) {
                counted[int(values[v_index]/line_height)] += 1
        }
        line=0
        max_width=0
        while(line <= number_of_lines) {
                if(max_width<counted[line]) max_width = counted[line]
                line++
        }
        line=0
        records_so_far = 0
        printf("%8s %8s %8s %s\n","Value","Height","%ile","Histogram")
        while(line <= number_of_lines) {
                records_so_far += counted[line]
                bar_width=counted[line]*LINE_WIDTH/max_width
                bar=""
                while (bar_width-->0) bar=bar "#"
                printf("%8d %8d %8.4f %s\n",line * line_height,counted[line],100*records_so_far/number_of_records, bar)
                line ++
        }
}