在蜘蛛图中移动ggplot x轴标签文本

Question

我有以下数据集。请注意，这些都是虚构的值：

Farm    CO2Fert CO2Manure   CO2Feed CO2Housing  CO2Fuel CO2Other
Best    2.187635996 0.670289261 0.773605214 2.415801361 1.180859203 2.876050311
Worst   4.240789564 0.503797793 1.884548328 5.114791701 3.411847194 5.150085802
User    1.189743632 2.852713125 0.419821994 0.630429463 2.982960729 1.489036959

我被要求绘制这些值的蜘蛛图。看了fmsb和ggradar之后，我有很多理由决定从头开始。所以，我有以下代码（目前还不确定是否所有库都是必需的）：

library(dplyr)
library(ggplot2)
library(scales)
library(reshape2)
library(tibble)
library(data.table)

data <- fread("C:/myData/ExampleFootprintData.csv")
dat2test <- melt.data.table(data, c("Farm"), c("CO2Fert", "CO2Manure", "CO2Feed", "CO2Fuel", "CO2Housing", "CO2Other"))

thePlot <-  ggplot(data = dat2test, aes(x=variable, y=value, group=Farm, color= Farm)) + ## Define data and colour column
  geom_polygon(fill = NA) + ## make the lines meet
  coord_polar() ## Make it round

图表如下：

正如您所看到的，标签未完全位于绘图表面上。查看互联网上的示例（例如the main text I've taken my code from），这似乎无法在任何地方解决。这个here有一个有趣的解决方案，我正在考虑使用它，但我的最终标签可能很长且具有描述性。我希望它们能够水平显示，因为它们现在有适当的换行符，但它们适合图表。

到目前为止，我对此并不是很了解。使用theme(axis.title.x = element_text(vjust=-0.5))或类似功能不起作用，但如果我使用建议here的边距，例如theme(axis.text.x = element_text(margin = margin(t = -20)))所有改变的是x轴标题向内移动到扩展的绘图区域，但标签仍在图表之外：

如何强制ggplot将我的标签保留在绘图的物理区域内？

数据输入：

structure(list(Farm = c("Best", "Worst", "User"), CO2Fert = c(2.187635996, 
4.240789564, 1.189743632), CO2Manure = c(0.670289261, 0.503797793, 
2.852713125), CO2Feed = c(0.773605214, 1.884548328, 0.419821994
), CO2Housing = c(2.415801361, 5.114791701, 0.630429463), CO2Fuel = c(1.180859203, 
3.411847194, 2.982960729), CO2Other = c(2.876050311, 5.150085802, 
1.489036959), NO3Fert = c(2.19509301, 1.848317101, 1.643695528
), NO3Manure = c(2.452857906, 3.153028268, 1.922113286), NO3Grazing = c(0.037698451, 
4.452847769, 2.546101867), NH4Spreading = c(2.880954824, 2.60492997, 
3.186211336), NH4Storage = c(1.178815284, 4.893388111, 2.432823901
), NH4Grazing = c(0.509207305, 2.998872111, 4.444466334), NH4Housing = c(2.523406518, 
5.255666955, 1.287199958)), .Names = c("Farm", "CO2Fert", "CO2Manure", 
"CO2Feed", "CO2Housing", "CO2Fuel", "CO2Other", "NO3Fert", "NO3Manure", 
"NO3Grazing", "NH4Spreading", "NH4Storage", "NH4Grazing", "NH4Housing"
), row.names = c(NA, -3L), class = c("data.table", "data.frame"
), .internal.selfref = <pointer: 0x0000000000120788>)

Answer 1

一种可能的解决方法：

library(grid)

gt <- ggplot_gtable(ggplot_build(thePlot))
gt$layout$clip[gt$layout$name == "panel"] <- "off"
grid::grid.draw(gt)

结果：

Answer 2

# Simply add an annotation layer and remove y axis text

    thePlot <-  ggplot(data = dat2test, aes(x=variable, y=value, group=Farm, color= Farm)) + 
      geom_polygon(fill = NA) + 
      coord_polar()+
      annotate('text', x=.5, y=c(1,2,3,4,5), label=c(1,2,3,4,5))+
      theme(axis.text.y = element(blank),
            axis.tick.y = element(blank))