将ggplot geo_geom_histogram()与y-log-scale一起使用为零箱 [英] Using ggplot geo_geom_histogram() with y-log-scale with zero bins

问题描述

我有一个集合，其中有> 10000个整数，其值在1到500之间.我想以直方图的形式绘制值，但是，由于只有少数整数的值大于200，因此我想对y轴使用对数刻度.

I've got a set with >10000 integers attaining values between 1 and 500. I want to plot the values in form of a histogram, however, since only a few integers attain values greater than 200, I want to use a logarithmic scale for the y-axis.

一个箱的计数为零时出现问题，因为对数值变为-无限大.

A problem emerges, when one bin has a count of zero, since the logarithmic value goes to -infinity.

为避免这种情况，我想向每个bin添加一个伪计数1.在标准的hist()图中，我可以按照以下步骤进行操作:

To avoid this, I want to add a pseudocount of 1 to each bin. In a standard hist()-plot I can do this like follows:

hist.data = hist(data, plot=F, breaks=30)
hist.data$counts = log10(hist.data$counts + 1)
plot(hist.data, ...)

但是，我很难找到一种方法来访问ggplot中的计数.

However, I struggle to find a way to access the counts in ggplot.

是否有一种简单的方法可以解决此问题?

Is there a simple way to do this, or are there other recommended ways to deal with this problem?

推荐答案

实现此目标的一种方法是编写自己的y缩放函数.ggplot2使用的转换函数(例如，当使用 scale_y_log10()时)在 scales 包中定义.

One way to achieve this is to write your own transformation function for the y scale. Transformations functions used by ggplot2 (when using scale_y_log10() for instance) are defined in the scales package.

library(ggplot2)
library(scales)

mylog10_trans <- function (base = 10) 
{
  trans <- function(x) log(x + 1, base)
  inv <- function(x) base^x
  trans_new(paste0("log-", format(base)), trans, inv, log_breaks(base = base), 
            domain = c(1e-100, Inf))
}

ggplot(df, aes(x=x)) + 
  geom_histogram() + 
  scale_y_continuous(trans = "mylog10")

输出

此图使用的数据:

df <- data.frame(x=sample(1:100, 10000, replace = TRUE))
df$x[sample(1:10000, 50)] <- sample(101:500, 50)

解释trans函数

让我们检查 scales :: log10_trans ;它调用 scales :: log_trans();现在， scales :: log_trans 打印为:

Explaining the trans function

Let's examine scales::log10_trans; it calls scales::log_trans(); now, scales::log_transprints as:

function (base = exp(1)) 
{
    trans <- function(x) log(x, base)
    inv <- function(x) base^x
    trans_new(paste0("log-", format(base)), trans, inv, log_breaks(base = base), 
        domain = c(1e-100, Inf))
}
<environment: namespace:scales>

在上面的答案中，我替换为:

In the answer above, I replaced:

trans <- function(x) log(x, base)

具有:

trans <- function(x) log(x + 1, base)

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