当标题是ggplot2中的变量时,如何更改标题标题的字体大小？

Question

我正在使用ggplot2生成散点图.我把标题变成了变量,如何更改字体大小？代码如下:

library("ggplot2")
plotfunc <- function(x){
    x +
    geom_point() +
    geom_smooth(se = FALSE, method = "lm",  color = "blue", size = 1) +
    opts(title = plottitle,
           axis.title.x = theme_text(size = 8, colour = 'black'),
         axis.title.y = theme_text(size = 8, colour = 'black', angle = 90))
}

plottitle <- "This is Title"
p <- ggplot(data = iris, aes(x = Sepal.Length, y = Sepal.Width))
plotfunc(p)

我试过了

opts(title = plottitle (size = 10),...

但是有一个错误:

Error in opts(title = plottitle(size = 10),
axis.title.x = theme_text(size = 8,  : could not find function "plottitle"

它被认为是不是我想要的功能.我该怎么办？谢谢.

Answer 1

如果opts()仍然适用于您,那么您使用的是旧版本的ggplot2.较新的命令是theme().在任何情况下,您都不希望将实际标题标签放入opts或主题 - 使用labs()

plotfunc <- function(x) {
  x +
    geom_point() +
    geom_smooth(se = FALSE, method = "lm",  color = "blue", size = 1) +
    theme_bw() +
    theme(axis.title.x = element_text(size = 8, colour = 'black'),
          axis.title.y = element_text(size = 8, colour = 'black', angle = 90)) +
    labs(title='this', x='that', y='the other')
}

## plottitle <- "This is Title"
p <- ggplot(data = iris, aes(x = Sepal.Length, y = Sepal.Width))
plotfunc(p)

Answer 2

可笑的迟到答案,但我不认为现有的答案解决了实际问题:

我把标题变成了变量,如何更改字体大小？

这对我有用,并且在更新的ggplot语法中(theme()vs. opts()):

library(ggplot2)
plotfunc <- function(x){
    x +
    geom_point() +
    geom_smooth(se = FALSE, method = "lm",  color = "blue", size = 1) +
    labs(title = plottitle) +
    ### pay attention to the ordering of theme_bw() vs. theme()
    theme_bw() +
    theme(plot.title = element_text(size = 20),
          axis.title.x = element_text(size = 12),
          axis.title.y = element_text(size = 8))

}

plottitle <- "This is Title"
p <- ggplot(data = iris, aes(x = Sepal.Length, y = Sepal.Width))
plotfunc(p)

我得到以下内容:

关于我的theme_bw()评论的一个注释:尝试运行上面的内容,但是在theme_bw()最后theme(plot.title, ...)一点之后,就像上面的Stephen Henderson的回答一样.您会注意到没有任何字体大小生效.这是因为如果在添加后将其传递theme_bw(),则会覆盖各种自定义theme()选项的预设.

只是一个值得注意的东西; 我只是学会了它,因为theme_bw()我使用了很多东西,并试着弄清楚为什么其他theme()选项不起作用,然后才意识到它不是我的ggplot语法,而是我的设置顺序.得爱编码:)

此外,这里是您可以传递的完整选项列表,theme()作为您可以调整的内容和方法的参考.

Answer 3

您将“(”作为下一个非空白字符，plottitle因此解释器认为它必须是一个函数。尝试

  .... opts( title=plottile, size=10)

这是一长串温暖的信息：

Warning messages:
1: 'opts' is deprecated.
Use 'theme' instead.
See help("Deprecated") 
2: 'theme_text' is deprecated.
Use 'element_text' instead.
See help("Deprecated") 
3: 'theme_text' is deprecated.
Use 'element_text' instead.
See help("Deprecated") 
4: In opts(title = plottitle, axis.title.x = theme_text(size = 8, colour = "black"),  :
  Setting the plot title with opts(title="...") is deprecated. Use labs(title="...") or ggtitle("...") instead.