Data commit

Task/Mandelbrot-set/Emacs-Lisp/mandelbrot-set-1.l

@@ -0,0 +1,42 @@
+; === Mandelbrot ============================================
+
+(setq mandel-size (cons 76 34))
+(setq xmin -2)
+(setq xmax .5)
+(setq ymin -1.2)
+(setq ymax 1.2)
+(setq max-iter 20)
+
+(defun mandel-iter-point (x y)
+  "Run the actual iteration for each point."
+  (let ((xp 0)
+        (yp 0)
+        (it 0)
+        (xt 0))
+    (while (and (< (+ (* xp xp) (* yp yp)) 4) (< it max-iter))
+      (setq xt (+ (* xp xp) (* -1 yp yp) x))
+      (setq yp (+ (* 2 xp yp) y))
+      (setq xp xt)
+      (setq it (1+ it)))
+    it))
+
+(defun mandel-iter (p)
+  "Return string for point based on whether inside/outside the set."
+  (let ((it (mandel-iter-point (car p) (cdr p))))
+    (if (= it max-iter) "*" "-")))
+
+(defun mandel-pos (x y)
+  "Convert screen coordinates to input coordinates."
+  (let ((xp (+ xmin (* (- xmax xmin) (/ (float x) (car mandel-size)))))
+        (yp (+ ymin (* (- ymax ymin) (/ (float y) (cdr mandel-size))))))
+       (cons xp yp)))
+
+(defun mandel ()
+  "Plot the Mandelbrot set."
+  (dotimes (y (cdr mandel-size))
+    (dotimes (x (car mandel-size))
+      (if (= x 0)
+        (insert(format "\n%s" (mandel-iter (mandel-pos x y))))
+        (insert(format "%s" (mandel-iter (mandel-pos x y))))))))
+
+(mandel)

Task/Mandelbrot-set/Emacs-Lisp/mandelbrot-set-2.l

@@ -0,0 +1,54 @@
+; === Graphical Mandelbrot ============================================
+
+(setq mandel-size (cons 320 300))
+(setq xmin -2)
+(setq xmax .5)
+(setq ymin -1.2)
+(setq ymax 1.2)
+(setq max-iter 20)
+
+(defun mandel-iter-point (x y)
+  "Run the actual iteration for each point."
+  (let ((xp 0)
+        (yp 0)
+        (it 0)
+        (xt 0))
+    (while (and (< (+ (* xp xp) (* yp yp)) 4) (< it max-iter))
+      (setq xt (+ (* xp xp) (* -1 yp yp) x))
+      (setq yp (+ (* 2 xp yp) y))
+      (setq xp xt)
+      (setq it (1+ it)))
+    it))
+
+(defun mandel-iter (p)
+  "Return string for point based on whether inside/outside the set."
+  (let ((it (mandel-iter-point (car p) (cdr p))))
+    (if (= it max-iter) "*" (if (cl-oddp it) "+" "-"))))
+
+(defun mandel-pos (x y)
+  "Convert screen coordinates to input coordinates."
+  (let ((xp (+ xmin (* (- xmax xmin) (/ (float x) (car mandel-size)))))
+        (yp (+ ymin (* (- ymax ymin) (/ (float y) (cdr mandel-size))))))
+       (cons xp yp)))
+
+(defun string-to-image (str)
+  "Convert image data string to XPM image."
+  (create-image (concat (format "/* XPM */
+static char * mandel[] = {
+\"%i %i 3 1\",
+\"+      c #ff0000\",
+\"-      c #0000ff\",
+\"*      c #000000\"," (car mandel-size) (cdr mandel-size))
+    str "};") 'xpm t))
+
+(defun mandel-pic ()
+  "Plot the Mandelbrot set."
+  (setq all "")
+  (dotimes (y (cdr mandel-size))
+    (setq line "")
+    (dotimes (x (car mandel-size))
+      (setq line (concat line (mandel-iter (mandel-pos x y)))))
+    (setq all (concat all "\"" line "\",\n")))
+  (insert-image (string-to-image all)))
+
+(mandel-pic)