def gen_yticks(max_pt):
    """Generates an array of y-axis ticks in integers - step is determined by the largest data point"""
    if max_pt <= 10:
        step = 1
    elif max_pt <= 50:
        step = 5
    elif max_pt <= 100:
        step = 10
    elif max_pt <= 500:
        step = 50
    else:
        step = 100

    return range(0, max_pt + step, step)