Julia fractal using Clojure and dtype-next

deps.edn

{:deps {org.clojure/clojure {:mvn/version "1.12.3"}
        org.scicloj/noj {:mvn/version "2-beta18"}}}

julia.clj

(ns fractals.julia
    (:require [tech.v3.tensor :as dtt]
              [tech.v3.libs.buffered-image :as bufimg])
    (:import [javax.imageio ImageIO]
             [java.io File]))

(defn sq [x] (* x x))

(def w 1920)
(def h (quot (* w 9) 16))

(def t (dtt/compute-tensor
         [h w]
         (fn [y x]
             (loop [zr (+ -1.5 (* x (/ 3.0 w)))
                    zi (+ -0.9 (* y (/ 1.8 h)))
                    i  0]
                   (if (or (>= i 200) (> (+ (sq zr) (sq zi)) 4))
                     (- 255 (quot (* i 255) 200))
                     (recur (- (sq zr) (sq zi) 0.79)
                            (+ (* zr zi 2) 0.15)
                            (inc i)))))
         :uint8))

(def image (bufimg/tensor->image t))

(ImageIO/write image "png" (File. "julia.png"))