def METHOD_NAME( array_2d, array_1d ) :
    """
    Copy array_2d to array_1d, so that the first axis of array_2d
    is contiguous in array_1d
    This is typically done before using the cuFFT API,
    which requires 1d arrays to do FFT in only one dimension.
    Parameters :
    ------------
    array_2d : 2darray of complexs
        Array of shape (Nz, Nr)
    array_1d : 1d array of complexs
        Array of shape (Nz*Nr,)
    """
    # Set up cuda grid
    iz, ir = cuda.grid(2)
    # Copy from array_2d to array_1d
    if (iz < array_2d.shape[0]) and (ir < array_2d.shape[1]) :
        i = iz + array_2d.shape[0]*ir
        array_1d[i] = array_2d[iz, ir]