base R：如何将行标题添加到 2 x 2 图

Question

我有一个 2 x 2 的图形，其中列代表两个不同的变量，行代表两个不同的位置。 如何将两个位置的名称添加到两行中？

示例数据

library(biwavelet)

par(mfrow = c(2,2),
    oma = c(3,3,0,0) + 0.1,
    mar = c(1,1,1,1) + 0.1)

dat <- as.data.frame(matrix(nrow = 500, ncol = 2))

dat[1] <- seq(1,500)
dat[2] <- sin(dat[1])

# top-left figure
plot(wt(dat),
     xaxt = 'n',
     xlab = "",
     cex.axis = 1.5,
     cex.lab = 1.5)
axis(1, at = seq(0, 500, by = 100), cex.axis = 0.1, col.axis = 'NA')
title("Variable 1", line = 0.1, cex.main = 1.5)

# top-right figure
dat[2] <- sin(dat[1]*.5)
plot(wt(dat),
     xaxt = 'n',
     col.axis = 'NA',
     xlab = "",
     ylab = "")
axis(1, at = seq(0, 500, by = 100), cex.axis = 0.1, col.axis = 'NA')
title("Variable 2", line = 0.1, cex.main = 1.5)

# bottom-left figure
dat[2] <- sin(dat[1]*.25)
plot(wt(dat),
     cex.axis = 1.5)

# bottom-right figure
dat[2] <- sin(dat[1]*.125)
plot(wt(dat),
     col.axis = 'NA',
     ylab = "",
     xlab = "")
axis(1, at = seq(0, 500, by = 100), cex.axis = 1.5)

title(xlab = "Time (hours)",
      ylab = "Period",
      outer = TRUE,
      line = 1.5,
      cex.lab = 1.5)

理想的身材应该是这样的

Answer 1

这是一种方法：

par(mfrow=c(2,2))
par(mar = c(1,1,1,1) + 0.1)
plot(disp ~ mpg, data = mtcars)
mtext("disp 1", side=3)
plot(I(2*disp) ~ mpg, data = mtcars)
mtext("disp 2", side=3)
mtext("mpg 1", side=4)
plot(disp ~ I(2*mpg), data = mtcars)
plot(I(2*disp) ~ I(2*mpg), data = mtcars)
mtext("mpg 2", side=4)

不幸的是， mtext不支持旋转文本，因此您只能使用正确的标签按原样定向。

Answer 2

到目前为止，建议的解决方案都没有将右侧标签放在所要求的方向上。 您不能使用mtext这样做，而是需要使用text ，首先允许text显示在 plot 区域之外par(xpd=NA) 。 （见?text和?par ，其中有人读到srt ，旋转，参数只适用于text ）：

par(mfrow=c(2,2), xpd=FALSE)
par(mar = c(1,1,1,1) + 2)
plot(disp ~ mpg, data = mtcars)
mtext("disp 1", side=3)
plot(I(2*disp) ~ mpg, data = mtcars)
mtext("disp 2", side=3); par(xpd=NA)
text("mpg 1",  x=36, y=500, srt=270)
plot(disp ~ I(2*mpg), data = mtcars); par(xpd=NA)
plot(I(2*disp) ~ I(2*mpg), data = mtcars)
text("mpg 2",  x=72, y=500, srt=270)

它不像mtext那样自动，因为需要分别查看每个绘图图形才能得出绘图坐标中 x 和 y 位置的估计值。

Answer 3

万一有人无意中看到这个页面，我最终使用的代码是基于@IRTFM 的回答，见下文。 在text() function 中找到合适的y =具有挑战性。我使用迭代方法发现y =比我预期的要低得多。

library(biwavelet)

par(mfrow = c(2,2), xpd=F)
par(mar = c(1,1,1.1,1.1) + 0.1,
    oma = c(3,3,0.5,0.5) + 0.1)

dat <- as.data.frame(matrix(nrow = 500, ncol = 2))

dat[1] <- seq(1,500)
dat[2] <- sin(dat[1])

# top-left figure
plot(wt(dat),
     xaxt = 'n',
     xlab = "",
     cex.axis = 1.5,
     cex.lab = 1.5)
axis(1, at = seq(0, 500, by = 100), cex.axis = 1.5, col.axis = 'NA')
mtext("Variable 1", side = 3, cex = 1.5, line = 0.1)
box(lty = "solid", col = 'black')

# top-right figure
dat[2] <- sin(dat[1]*.5)
plot(wt(dat),
     xaxt = 'n',
     col.axis = 'NA',
     xlab = "",
     ylab = "")
axis(1, at = seq(100, 500, by = 100), cex.axis = 0.1, col.axis = 'NA')
mtext("Variable 2", side = 3, cex = 1.5, line = 0.1)
text("Location 1", x = 520, y = 4.1, srt = 270, cex = 1.5, xpd=NA)
box(lty = "solid", col = 'black')

# bottom-left figure
dat[2] <- sin(dat[1]*.25)
plot(wt(dat),
     cex.axis = 1.5,
     xlab = "",
     ylab = "")
axis(1, at = seq(100, 500, by = 100), cex.axis = 1.5)
box(lty = "solid", col = 'black')

# bottom-right figure
dat[2] <- sin(dat[1]*.125)
plot(wt(dat),
     col.axis = 'NA',
     ylab = "",
     xlab = "")
axis(1, at = seq(100, 500, by = 100), cex.axis = 1.5)
text("Location 2", x = 520, y = 4.5, srt = 270, cex = 1.5, xpd=NA)
box(lty = "solid", col = 'black')

title(xlab = "Time (hours)",
      ylab = "Period",
      outer = TRUE,
      line = 1.5,
      cex.lab = 1.5)