您将如何对直方图进行归一化，以便每个bin的总和为1? [英] How would you normalize a histogram so the sum of each bin is 1?

问题描述

如何对直方图A进行归一化，使每个bin的总和为1

How would you normalize a histogram A so the sum of each bin is 1

将直方图除以垃圾箱的宽度，如何绘制

Dividing the histogram by the width of the bin, how do you draw it

我有这个

dist        = rand(50)    
average     = mean(dist, 1);   
[c,x]       = hist(average, 15);    
normalized  = c/sum(c);
bar(x, normalized, 1)

在这种情况下，n = 50

• 获取值的公式是什么 均值和方差^ 2?我们写N(mean, (variance^2) / 50)，但是如何?
• 如何绘制均匀分布和正态分布?

• What is it the formula to get values of mean and variance^2? We write N(mean, (variance^2) / 50), but how?
• How do you plot both uniform distribution and normal distribution?.

直方图必须接近正态分布.

The histogram must be close to the normal distribution.

推荐答案

这是标准化概率密度函数的一种非常不寻常的方法.我假设您要归一化，以使曲线下的面积为1.在这种情况下，这就是您应该做的.

That is a very unusual way of normalizing a probability density function. I assume you want to normalize such that the area under the curve is 1. In that case, this is what you should do.

[c,x]=hist(average,15);
normalized=c/trapz(x,c);
bar(x,normalized)

无论哪种方式，要回答您的问题，都可以使用randn生成正态分布.现在，您将生成一个50x50均匀分布矩阵，并沿一维求和以近似正态高斯.这是没有必要的.要生成1000个点的正态分布，请使用randn(1000,1)；如果需要行向量，请对其进行转置或翻转数字.要生成均值mu和方差sigma2的高斯分布，并绘制其pdf，可以这样做(一个示例)

Either way, to answer your question, you can use randn to generate a normal distribution. You're now generating a 50x50 uniform distribution matrix and summing along one dimension to approximate a normal Gaussian. This is unnecessary. To generate a normal distribution of 1000 points, use randn(1000,1) or if you want a row vector, transpose it or flip the numbers. To generate a Gaussian distribution of mean mu and variance sigma2, and plot its pdf, you can do (an example)

mu=2;
sigma2=3;
dist=sqrt(sigma2)*randn(1000,1)+mu;
[c,x]=hist(dist,50);
bar(x,c/trapz(x,c))

尽管可以使用统计工具箱中的专用功能来完成这些操作，但这同样直接，简单，并且不需要其他工具箱.

Although these can be done with dedicated functions from the statistics toolbox, this is equally straightforward, simple and requires no additional toolboxes.

编辑

我错过了您想知道如何生成均匀分布的部分. rand，默认情况下为您提供[0,1]上均匀分布的随机变量.取得R.V.从[a, b]之间的均匀分布中，使用a+(b-a)*rand

I missed the part where you wanted to know how to generate a uniform distribution. rand, by default gives you a random variable from a uniform distribution on [0,1]. To get a r.v. from a uniform distribution between [a, b], use a+(b-a)*rand

这篇关于您将如何对直方图进行归一化，以便每个bin的总和为1?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！