基于小时的概率运行

Question

我有一个函数，我希望每小时运行的概率越来越高，直到正午，然后将概率降低到午夜。我可以想象一个以正午为中心的正态分布会这样做（所以运行函数的概率在正午时为100％但在午夜时非常低），但我无法将其转换为python代码。

例如，如果代码在凌晨1点执行，则运行概率非常低。但如果代码在中午执行，则它有100％的运行概率。

这是一个完全粗暴，单一的，手工尝试我想要的东西：

currentHour = 12

if currentHour == 1:
    print('probability = 0')
elif currentHour == 2:
    print('probability = 0')
elif currentHour == 3:
    print('probability = .1')
elif currentHour == 4:
    print('probability = .2')
elif currentHour == 5:
    print('probability = .3')
elif currentHour == 6:
    print('probability = .4')
elif currentHour == 7:
    print('probability = .5')
elif currentHour == 8:
    print('probability = .6')
elif currentHour == 9:
    print('probability = .7')
elif currentHour == 10:
    print('probability = .8')
elif currentHour == 11:
    print('probability = .9')
elif currentHour == 12:
    print('probability = 1')
elif currentHour == 13:
    print('probability = .9')
elif currentHour == 13:
    print('probability = .8')
elif currentHour == 14:
    print('probability = .7')
elif currentHour == 15:
    print('probability = .6')
elif currentHour == 16:
    print('probability = .5')
elif currentHour == 17:
    print('probability = .4')
elif currentHour == 18:
    print('probability = .3')
elif currentHour == 19:
    print('probability = .2')
elif currentHour == 20:
    print('probability = .1')
elif currentHour == 21:
    print('probability = 0')
elif currentHour == 22:
    print('probability = 0')
elif currentHour == 23:
    print('probability = 0')
elif currentHour == 24:
    print('probability = 0')

Answer 1

纯粹的魔法。我想到了。不，只是在开玩笑。当你问这个问题时，它立刻让我想起了窦波，它们再次上升然后再下降 - 就像你想要做的那样。

根据this页面：

  

由y = sin x定义的函数图称为正弦波或正弦波。 [...]此图重复每6.28单位或2 pi弧度。范围从-1到1.

所以我想出了这个：

sin((hour/24)*pi)

你可以像这样在python中集成它：

import math
import time
hour = int(time.strftime("%H"))
probability = math.sin(hour/24.0*math.pi)
print(probability)

为什么呢？因为sin(0*pi)是0而sin(0.5*pi)是1。你希望在12小时时概率最高，所以1。该值出现在sin(0.5*pi)上。 24小时后，该值将为sin(1*pi)，再次为0。

然后我将该值从0转换为1，转换为0和24，将当前小时除以24。

Answer 2

很多选择。只需创建一个函数，该函数根据小时返回0到1之间的值。然后，在0和1之间进行随机浮动。如果浮点数小于概率，则运行程序。

import numpy as np

def prob_sawtooth(hour):
    return 1. - abs((hour - 12.) / 12.)

def prob_sin(hour):
    return np.sin(hour / 24. * np.pi)

def prob_gaussian(hour, stdev=6.):
    gauss = lambda x, m, s: np.exp(-(x-m)**2 / (2*s**2)) / np.sqrt(2*np.pi*s**2)
    return gauss(hour, 12., stdev) / gauss(12., 12., stdev)

test = np.random.rand()
#14:00
if test <= prob_gaussian(14.):
    # run program
    pass