R：更改森林图中的 x 轴刻度线标签

Question

library(forestplot)
# Cochrane data from the 'rmeta'-package
cochrane_from_rmeta <- 
  structure(list(
    mean  = c(NA, NA, 0.578, 0.165, 0.246, 0.700, 0.348, 0.139, 1.017, NA, 0.531), 
    lower = c(NA, NA, 0.372, 0.018, 0.072, 0.333, 0.083, 0.016, 0.365, NA, 0.386),
    upper = c(NA, NA, 0.898, 1.517, 0.833, 1.474, 1.455, 1.209, 2.831, NA, 0.731)),
    .Names = c("mean", "lower", "upper"), 
    row.names = c(NA, -11L), 
    class = "data.frame")

tabletext<-cbind(
  c("", "Study", "Auckland", "Block", 
    "Doran", "Gamsu", "Morrison", "Papageorgiou", 
    "Tauesch", NA, "Summary"),
  c("Deaths", "(steroid)", "36", "1", 
    "4", "14", "3", "1", 
    "8", NA, NA),
  c("Deaths", "(placebo)", "60", "5", 
    "11", "20", "7", "7", 
    "10", NA, NA),
  c("", "OR", "0.58", "0.16", 
    "0.25", "0.70", "0.35", "0.14", 
    "1.02", NA, "0.53"))

forestplot(tabletext, 
           cochrane_from_rmeta,new_page = TRUE,
           is.summary=c(TRUE,TRUE,rep(FALSE,8),TRUE),
           clip=c(0.1,2.5), 
           xlog=TRUE, 
           col=fpColors(box="royalblue",line="darkblue", summary="royalblue"))

我有一个森林图，我的 x 轴刻度线标签的间距有点奇怪，我想将其更改为让每个刻度线彼此相距 0.1。另外，有谁知道森林图如何决定蜱虫的间距？

Answer 1

从

forestplot

文档（https://cran.r-project.org/web/packages/forestplot/vignettes/forestplot.html#ticks-and-grids），您有两个选择。

1. 您可以在

   forestplot()

   表达式中手动设置您的刻度，例如

   xticks = c(-.1, -0.05, 0, .05)

2. 您可以创建一个序列，例如

   xticks <- seq(from = -0.08, to = 2.50, by = 0.1)

   并将其添加到您的

   forestplot()

   表达式中

   xticks = xticks

Answer 2

为了稍微扩展上面的答案，您可以使用类似此代码的代码来自动获取报价的良好范围。您需要指定您引用的是

lower

列表中的

cochrane_from_rmeta

。

x_min <- min(lower) - 1  # Extend range slightly for better visualisation
x_max <- max(upper) + 1
x_ticks <- seq(floor(x_min), ceiling(x_max), by = 2)  # Adjust 'by' for desired interval