Compute the Mandelbrot set using jq.

mandelbrot-jq.sh

#!/bin/bash
jq -r -n --argjson limit 150 --argjson size_x 140 --argjson size_y 400 '
    def add_i($a;$b): [$a[0]+$b[0],$a[1]+$b[1]];
    def mult_i($a;$b): [$a[0]*$b[0]-$a[1]*$b[1], $a[0]*$b[1]+$b[0]*$a[1]];
    def norm($a): $a[0]*$a[0]+$a[1]*$a[1] | sqrt;
    def compute_c: [-2.0+.[0]*2.5/$size_x+0.8, 1.15-.[1]*2.3/$size_y*1.2+0.22];
    def compute_z($iter;$c):
        if ($iter == 0) or (norm(.) >= 4) then $iter
        else
            add_i(mult_i(.;.); $c//[0,0]) | compute_z($iter-1; $c//.)
        end
    ;
    def get_letter:
        (" 123456789abcdefghijklmnopqrstuvwxyz" | split("")) as $letters |
        $letters[.%($letters|length)]
    ;
    def compute_letter:
        compute_c | compute_z($limit;null) | get_letter
    ;
    def to_text:
        map(.|join(""))|join("\n")
    ;
    def generate_coordinates:
        [ range($size_x) as $x | range($size_y) as $y | [$x,$y] ] | group_by(.[0])
    ;
    generate_coordinates | map(map(compute_letter)) | to_text
'

I don't know why it mirror on the X axis :-/