ggplot2：有没有一种方法可以将单个绘图覆盖到ggplot中的所有刻面 [英] ggplot2: Is there a way to overlay a single plot to all facets in a ggplot

问题描述

我想用ggplot和faceting来构建一系列按因子分组的密度图。另外，我希望在每个面上都有一层不受该面强加的约束的另一个密度图。

I would like to use ggplot and faceting to construct a series of density plots grouped by a factor. Additionally, I would like to a layer another density plot on each of the facets that is not subject to the constraints imposed by the facet.

例如，分面图如下：

For example, the faceted plot would look like this:

require(ggplot2)
ggplot(diamonds, aes(price)) + facet_grid(.~clarity) + geom_density()

然后我希望在每个方面都有以下单一密度图：

and then I would like to have the following single density plot layered on top of each of the facets:

ggplot(diamonds, aes(price)) + geom_density()

此外，ggplot有faceting做到这一点的最佳方式，还是有一个首选的方法？

Furthermore, is ggplot with faceting the best way to do this, or is there a preferred method?

推荐答案

实现这一目标的一种方法是创建新的数据框 diamonds2 ，它只包含 price 然后两个 geom_density（）调用 - 一个将使用原始钻石，第二个使用 diamonds2 。在 diamonds2 中，不会有任何列清晰所有值都将用于所有方面。

One way to achieve this would be to make new data frame diamonds2 that contains just column price and then two geom_density() calls - one which will use original diamonds and second that uses diamonds2. As in diamonds2 there will be no column clarity all values will be used in all facets.

diamonds2<-diamonds["price"]
ggplot(diamonds, aes(price)) + geom_density()+facet_grid(.~clarity) + 
     geom_density(data=diamonds2,aes(price),colour="blue")

UPDATE - 正如@BrianDiggs所建议的那样，如果不创建新的数据框，但可以在 geom_density（）内转换它，可以实现相同的结果。

UPDATE - as suggested by @BrianDiggs the same result can be achieved without making new data frame but transforming it inside the geom_density().

ggplot(diamonds, aes(price)) + geom_density()+facet_grid(.~clarity) +
     geom_density(data=transform(diamonds, clarity=NULL),aes(price),colour="blue")

另一种方法是无需刻面即可绘制数据。将两个调用添加到 geom_density（） - 在一个添加 aes（color = clarity）中使用不同颜色的密度线对于清晰度的每个级别，并留下空的第二个 geom_density（） - 这将添加整个黑色密度线。

Another approach would be to plot data without faceting. Add two calls to geom_density() - in one add aes(color=clarity) to have density lines in different colors for each level of clarity and leave empty second geom_density() - that will add overall black density line.

ggplot(diamonds,aes(price))+geom_density(aes(color=clarity))+geom_density()

这篇关于ggplot2：有没有一种方法可以将单个绘图覆盖到ggplot中的所有刻面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！