Mandelbrot set of trigonometric function cos(z)

fractal {
	// Set region margins and declare state vector as [x,n] where x and n are built-in variables
	orbit [<-3.0,-3.0>,<3.0,3.0>] [x,n] {
		// Iterate for n from 0 to 200 stopping when abs(im(x)) > 100
		loop [0, 200] (abs(im(x)) > 100) {
			// Precalculate values
			xr = re(x);
			xi = im(x);
			wr = re(w);
			wi = im(w);
			ta = cos(xr);
			tb = sin(xr);
			tc = exp(+xi);
			td = exp(-xi);
			te = 0.5 * ta * (tc + td);
			tf = 0.5 * tb * (tc - td);
			zr = wr * te + wi * tf;
			zi = wi * te - wr * tf;
			// Set x to complex number zr + zi i
			x = <zr,zi>;
		}
	}
	// Set background color to alpha=1, red=1, green=1, blue=1
	color [(1,0,0,0)] {
		// Create palette with 200 colors and name gradient
		palette gradient {
			[#FFFF0000 > #FFFFFFFF, 10];
			[#FFFFFFFF > #FFFFFFFF, 190];
		}
		// Apply rule when n > 0 and set opacity to 1.0
		rule (n > 0) [1] {
			// Set color to element n - 1 of gradient (gradient has 200 colors starting from index 0)
			gradient[n - 1]
		}
	}
}