r - 使用表达式等创建多行标签

Question

这是代码示例

set.seed(1)
tmp <- matrix(replicate(4, rnorm(50)), ncol=4)
panel.cor <- function(x, y, digits=2, prefix="", cex.cor, ...)
{
  usr <- par("usr"); on.exit(par(usr))
  par(usr = c(0, 1, 0, 1))
  rp <- cor(x, y, method="pearson", use="pairwise.complete.obs")
  rs <- cor(x, y, method="spearman", use="pairwise.complete.obs")
  rp <- format(rp, digits=digits)
  rs <- format(rs, digits=digits)
  txt <- substitute(list(R[p] == rp, R[s] == rs), list(rp=rp, rs=rs))
  if(missing(cex.cor)) cex.cor <- 0.8/strwidth(txt)
  text(0.5, 0.5, txt, cex = 1.5)
}
panel.my.points <- function(x, y) {
  points(x, y)
  abline(0, 1)
}
pairs(tmp, 
      lower.panel=panel.cor, 
      upper.panel=panel.my.points, 
      labels=c("model 1\nD1", "model 2\nD1", "model 1\nD2", "model 2\nD2"))

返回绘图 但我想在不同的行上显示两个相关系数 Pearson 和 Spearman。对于普通文本，我插入 \n 来生成两行输出(如对角线上的标签)。我怎样才能在两行中输出相关系数？

Answer 1

分别定义 Pearson(下面代码中的 txta)和 Spearman (txtb) 系数，然后调用 text 两次怎么样:

set.seed(1)
tmp <- matrix(replicate(4, rnorm(50)), ncol=4)
panel.cor <- function(x, y, digits=2, prefix="", cex.cor, ...)
{
  usr <- par("usr"); on.exit(par(usr))
  par(usr = c(0, 1, 0, 1))
  rp <- cor(x, y, method="pearson", use="pairwise.complete.obs")
  rs <- cor(x, y, method="spearman", use="pairwise.complete.obs")
  rp <- format(rp, digits=digits)
  rs <- format(rs, digits=digits)
  txt <- substitute(list(R[p] == rp, R[s] == rs), list(rp=rp, rs=rs))
  txta <- substitute(R[p] == rp, list(rp=rp))
  txtb <- substitute(R[s] == rs, list(rs=rs))
  if(missing(cex.cor)) cex.cor <- 0.8/strwidth(txt)
  text(0.5, 0.6, txta, cex = 1.5)
  text(0.5, 0.4, txtb, cex = 1.5)
}
panel.my.points <- function(x, y) {
  points(x, y)
  abline(0, 1)
}
pairs(tmp, 
      lower.panel=panel.cor, 
      upper.panel=panel.my.points, 
      labels=c("model 1\nD1", "model 2\nD1", "model 1\nD2", "model 2\nD2"))

这给出: