如何更改ggplot2中轴标签上的小数位数?

Specifically, this is in a facet_grid. Have googled extensively for similar questions but not clear on the syntax or where it goes. What I want is for every number on the y-axes to have two digits after the decimal, even if the trailing one is 0. Is this a parameter in scale_y_continuous or element_text or...?

具体来说，这是在facet_grid中。曾在谷歌上搜索过类似的问题，但不清楚它们的语法或去向。我想要的是对于y轴上的每一个数字在小数点后都有两个数字，即使后面的数字是0。这个参数是scale_y_continuous还是element_text还是…?

row1 <- ggplot(sector_data[sector_data$sector %in% pages[[x]],], aes(date,price)) + geom_line() +
  geom_hline(yintercept=0,size=0.3,color="gray50") +
  facet_grid( ~ sector) +
  scale_x_date( breaks='1 year', minor_breaks = '1 month') +
  scale_y_continuous( labels = ???) +
  theme(panel.grid.major.x = element_line(size=1.5),
        axis.title.x=element_blank(),
        axis.text.x=element_blank(),
        axis.title.y=element_blank(),
        axis.text.y=element_text(size=8),
        axis.ticks=element_blank()
  )

1 个解决方案

#1

From the help for ?scale_y_continuous, the argument 'labels' can be a function:

从?scale_y_continuous的帮助中，参数“标签”可以是一个函数:

labels One of:

标签之一:

NULL for no labels

空没有标签

waiver() for the default labels computed by the transformation object

对于转换对象计算的默认标签，弃权()

A character vector giving labels (must be same length as breaks)

一个字符向量给予标签(必须与中断相同长度)

A function that takes the breaks as input and returns labels as output

将中断作为输入并返回标签作为输出的函数。

We will use the last option, a function that takes breaks as an argument and returns a number with 2 decimal places.

我们将使用最后一个选项，一个以break作为参数并返回一个小数点后两位的数字的函数。

#Our transformation function
scaleFUN <- function(x) sprintf("%.2f", x)

#Plot
library(ggplot2)
p <- ggplot(mpg, aes(displ, cty)) + geom_point()
p <- p + facet_grid(. ~ cyl)
p + scale_y_continuous(labels=scaleFUN)

#1