def METHOD_NAME(size):
    matrix_size = 2 * size + 1
    matrix = np.zeros((matrix_size, matrix_size))
    center = size
    for i in range(matrix_size):
        for j in range(matrix_size):
            dist = sqrt((i - center) * (i - center) + (j - center) * (j - center))
            if dist <= size:
                matrix[i, j] = dist
    return matrix