获取N个总和为M的随机数 [英] Getting N random numbers whose sum is M

问题描述

我想获得N个随机数字，其总和是一个值.

I want to get N random numbers whose sum is a value.

例如，假设我要5个总和为1的随机数.

For example, let's suppose I want 5 random numbers that sum to 1.

然后，一种有效的可能性是:

Then, a valid possibility is:

0.2 0.2 0.2 0.2 0.2

另一种可能性是:

0.8 0.1 0.03 0.03 0.04

以此类推.在创建模糊C均值的所有物矩阵时，需要用到此.

And so on. I need this for the creation of a matrix of belongings for Fuzzy C-means.

推荐答案

简短回答:

仅生成N个随机数，计算它们的和，然后将每个除以 总和乘以M.

Just generate N random numbers, compute their sum, divide each one by the sum and multiply by M.

更长的答案:

上述解决方案不不会产生均匀分布，这取决于这些随机数的用途，可能是一个问题. Matti Virkkunen提出的另一种方法:

The above solution does not yield an uniform distribution which might be an issue depending on what these random numbers are used for. Another method proposed by Matti Virkkunen:

生成0到1之间的N-1个随机数，将数字0和1相加 自己列出来，对它们进行排序，并采用以下差异 相邻的数字.

Generate N-1 random numbers between 0 and 1, add the numbers 0 and 1 themselves to the list, sort them, and take the differences of adjacent numbers.

我不确定这是否会产生均匀分布

I'm not sure if this yield an uniform distribution

这篇关于获取N个总和为M的随机数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！