:orphan:

mandel_vec
----------


Calculate Mandelbrot set using NumbaPro (vectorized version)


.. code-block:: python
    
    
    
    from builtins import range
    
    from numba import vectorize
    from timeit import default_timer as timer
    
    import numpy as np
    import gr
    
    sig = 'i8(uint32, f8, f8, f8, f8, uint32, uint32, uint32)'
    
    
    @vectorize([sig], target='parallel')
    def mandel(tid, min_x, max_x, min_y, max_y, width, height, iters):
        pixel_size_x = (max_x - min_x) / width
        pixel_size_y = (max_y - min_y) / height
    
        x = tid % width
        y = tid / width
    
        real = min_x + x * pixel_size_x
        imag = min_y + y * pixel_size_y
    
        c = complex(real, imag)
        z = 0.0j
        ci = 0
        inc = 1
    
        for i in range(iters):
            z = z * z + c
            if (z.real * z.real + z.imag * z.imag) >= 4:
                return ci
            ci += inc
            if ci == 0 or ci == 255:
                inc = -inc
    
        return 255
    
    
    def create_fractal(min_x, max_x, min_y, max_y, width, height, iters):
        tids = np.arange(width * height, dtype=np.uint32)
        return mandel(tids, np.float64(min_x), np.float64(max_x), np.float64(min_y),
                      np.float64(max_y), np.uint32(height), np.uint32(width),
                      np.uint32(iters))
    
    
    x = -0.9223327810370947027656057193752719757635
    y = 0.3102598350874576432708737495917724836010
    
    f = 0.5
    for i in range(200):
        start = timer()
        pixels = create_fractal(x-f, x+f, y-f, y+f, 500, 500, 400)
        dt = timer() - start
    
        print("Mandelbrot created in %f s" % dt)
        ca = 1000.0 + pixels.ravel()
    
        gr.clearws()
        gr.setviewport(0, 1, 0, 1)
        gr.setcolormap(13)
        gr.cellarray(0, 1, 0, 1, 500, 500, ca)
        gr.updatews()
    
        f *= 0.9