可扩展的有偏数生成器

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我正在尝试获得一个随机数生成器，它会产生偏差，因为它需要一个数字，并打印一个可能接近的数字.这是我现在所拥有的:

I am trying to get a random number generator that will be biased in that it takes a number, and prints a number that is likely to be close. Here's what I have now:

def biasedRandom(rangen, rangex, target, biaslevel=1): if rangen > rangex: raise ValueError("Min value is less than max value.") return if not target in range(rangen, rangex): raise ValueError("Bias target not inside range of random.") return num = random.randint(rangen, rangex) for i in range(biaslevel): distance = abs(num - target) num -= random.randint(0, distance) return num

这很有效，但它有时会给出完全离谱的数字；例如它曾经为 (1,100,30,60) 给出了 -246174068358.我想那里只有一个我没有看到的错误.

This works pretty well, however it has on occasion given completely outrageous numbers; e.g. it once gave -246174068358 for (1,100,30,60). I figure there is just a bug in there that I am not seeing.

提前致谢.

推荐答案

raise 退出函数——你不需要跟着 raise 跟 return

raise exits the function - you do not need to follow raise with return

range(lo, hi) 中的目标效率低下；为什么不 lo <= target <嗨?

target in range(lo, hi) is inefficient; why not lo <= target < hi?

import random def biasedRandom(lo, hi, target, steps=1): if lo >= hi: raise ValueError("lo should be less than hi") elif target < lo or target >= hi: raise ValueError("target not in range(lo, hi)") else: num = random.randint(lo, hi) for i in range(steps): num += int(random.random() * (target - num)) return num

随着步数的增加，这将很快收敛到目标；您可能需要进行一些试验分布以确保获得预期的结果，或者尝试改用 random.gauss.

As steps is increased, this will pretty rapidly converge on target; you might want to do some trial distributions to make sure that you are getting what you expected, or try using random.gauss instead.