:orphan:

mandel_gpu
----------


Calculate Mandelbrot set using NumbaPro (GPU version)


.. code-block:: python
    
    
    
    from numbapro import *
    from timeit import default_timer as timer
    
    import numpy as np
    import gr
    
    
    @cuda.jit(restype=uint32, argtypes=[f8, f8, uint32], device=True)
    def mandel(x, y, max_iters):
        c = complex(x, y)
        z = 0.0j
        ci = 0
        inc = 1
    
        for i in xrange(max_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
    
    
    @cuda.jit(argtypes=[f8, f8, f8, f8, uint8[:,:], uint32])
    def mandel_kernel(min_x, max_x, min_y, max_y, image, max_iters):
        height = image.shape[0]
        width = image.shape[1]
    
        pixel_size_x = (max_x - min_x) / width
        pixel_size_y = (max_y - min_y) / height
    
        startX = cuda.blockDim.x * cuda.blockIdx.x + cuda.threadIdx.x
        startY = cuda.blockDim.y * cuda.blockIdx.y + cuda.threadIdx.y
        gridX = cuda.gridDim.x * cuda.blockDim.x;
        gridY = cuda.gridDim.y * cuda.blockDim.y;
    
        for x in xrange(startX, width, gridX):
            real = min_x + x * pixel_size_x
            for y in xrange(startY, height, gridY):
                imag = min_y + y * pixel_size_y
                image[y, x] = mandel(real, imag, max_iters)
    
    
    x = -0.9223327810370947027656057193752719757635
    y = 0.3102598350874576432708737495917724836010
    
    image = np.zeros((500, 500), dtype = np.uint8)
    blockdim = (32, 8)
    griddim = (32, 16)
    
    f = 0.5
    for i in range(200):
        start = timer()
        d_image = cuda.to_device(image)
        mandel_kernel[griddim, blockdim](x-f, x+f, y-f, y+f, d_image, 400)
        d_image.to_host()
        dt = timer() - start
    
        print("Mandelbrot created in %f s" % dt)
        ca = 1000.0 + image.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