R语言：如何在2×2多面板图中保留每个子图的轴边框

问题：制作2行2列的4面板图时，单独绘制顶部两个子图时边框正常，但添加底部两个子图后，顶部子图的边框消失。尝试过box(lty = "solid", col = 'black')、plot()里的fg='black'和bty="o"都无效。

问题原因 #

你在绘制右上角子图时多次设置了par(xpd = NA)，这个参数会全局生效，后续所有绘图的元素都会被允许绘制到设备区域之外，导致顶部子图的边框被绘制在了可视区域外，看起来像是消失了。

修复方案 #

不要全局修改xpd参数，而是在需要绘制区域外文本时，临时在text()函数中指定xpd=NA，避免全局影响后续绘图。

以下是修正后的完整代码：

library(biwavelet)

# 初始化绘图参数，仅设置一次全局xpd=FALSE
par(mfrow = c(2,2), xpd=FALSE)
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)

# 左上角子图
dat[2] <- sin(dat[1])
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')

# 右上角子图
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)
# 在text函数中临时设置xpd=NA，不全局修改参数
text("Location 1", x = 520, y = 4.1, srt = 270, cex = 1.5, xpd = NA)
box(lty = "solid", col = 'black')

# 左下角子图
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')

# 右下角子图
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)
# 同样在text里临时设置xpd=NA
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)

关键修改点 #

• 移除所有全局的par(xpd = NA)调用，改为在text()函数内通过xpd=NA参数临时允许绘制区域外文本
• 保持初始的par(xpd=FALSE)，确保后续所有绘图元素（包括边框）都在可视区域内正常绘制

内容的提问来源于stack exchange，提问作者tassones