直方图不显示密度 [英] Histogram does not show densities

问题描述

我尝试了不同的功能和几个不同的参数，但直方图

I've tried different functions and several different arguments but the histogram

hist(estimator, probability=T, br=5)

不管我选择什么绘图函数或参数，

都不会在y轴上显示密度.向量估计量"包含100个介于0.4到0.6之间的值.

isn't showing densities on the y-axis no matter what plotting function or argument I choose. The vector "estimator" contains 100 values around between 0.4 and 0.6.

准确地说:创建历史对象，然后计算并更改密度并通过plot()再次进行绘制的方法，但是我不希望首先绘制历史对象:/

To be precise: the way by creating an hist object, then calculate and change the densities and plot it again by plot() works, but I don't want the hist object to be plotted in the first place :/

推荐答案

当您指定 probability = T (或更好的是 probability = TRUE )时，如果将 T 更改为除 TRUE 之外的其他内容，则会弄乱高度应略小于1，高度必须大于1，以使面积全部加到1.这使得叠加密度估算曲线或理论密度曲线或添加其他参考变得容易.

When you specify probability=T (or better yet probability=TRUE so that you don't get messed up if T is changed to something besides TRUE) is a scaling such that the entire area of the histogram bars add to 1, since the width of your bars is quite a bit less than 1 the heights need to be greater than 1 so that the areas all add to 1. This makes it easy to superpose a density estimate curve or a theoretical density curve or add other references.

通常，您应该只忽略y轴上的刻度标签(如果甚至不绘制它们，那会更好)，它们只会分散图表的重要部分.

In general you should just ignore the tick labels on the y-axis (it would be better if they were not even plotted), they just distract from the important parts of the plot.

许多人认为他们希望y轴刻度标签代表每个分组中观察值的比例(或百分比)(这对于您自己的自定义轴是可能的)，但是我认为这仍然是一种干扰.考虑一下如果更改直方图中条形/间隔的数量会发生什么，直方图的整体结构保持不变(前提是您不做大的改变)，但是y轴上的刻度标签有时会更改因此，最好忽略它们(或者首先不要产生它们).

Many people think they want the y-axis tick labels to represent the proportion (or percentage) of observations within each grouping (and that is possible with your own custom axis), but I think this is still a distraction. Consider what happens if you change the number of bars/intervals in the histogram, the overall structure of the histogram stays the same (provided you don't make to drastic a change), but the tick labels on the y-axis change, sometimes by quite a bit, so they are better ignored (or not produced in the first place).

如果您真的认为需要百分比(或比例)，那么代码就很简单:

If you really think that the percentages (or proportions) are needed then the code is as simple as:

x <- rgamma(327, 5, 3)

tmp <- hist(x, yaxt='n',ylab='Percent')
tmp2 <- pretty( tmp$counts/sum(tmp$counts)*100 )
axis(2, at=tmp2*sum(tmp$counts)/100, labels=tmp2)

如果需要，可以很容易地将其包装到函数中.

That could be easily wrapped into a function if you wanted.

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