anchor.diff:  ;; :xloc 0.29579232190635435
   ;; :yloc 0.48778241011705686
   
  -;;; "fractal" goes here.
  -
  -
   
   (defun map-val (x width xmin xmax)
  +  "Map a value from the range 0,width to the range xmin,xmax"
     (declare (x (unsigned-byte 32)))
     (declare (width (unsigned-byte 32)))
     (declare (xmin double-float))
  
positive.code: 		(dt (/ (- tmax tmin) cnt))
  		(xp nil)
  		(yp nil))
  	(cl-cairo2:with-png-file ((home-dir fname) :argb32 width height)
  							 (cl-cairo2:set-source-rgba 1.0 1.0 1.0 1.0)
  							 (cl-cairo2:paint)
  							 (cl-cairo2:translate 400.0 300.0)
  
negative.code: 		 (b (- 255 (* ip 255) )))
  	(set-pixel img x y (truncate r) (truncate g) (truncate b))))
  
  (defun make-mandelbrot (&key (file-name)
  							 (width 100) (height 100)
  							 (xmin -2.5) (xmax 1.0)
  							 (ymin -1.0) (ymax 1.0)
  							 (iterations 100))
    "Generate a Mandelbrot Set fractal and save to the file name given.  The portion of the set drawn is given by xmin,xmax and ymin,ymax."
    (declare (width (unsigned-byte 32)))
    (declare (height (unsigned-byte 32)))
    (declare (iterations (unsigned-byte 32)))
  