R语言绘图时底部居中图例与y轴标签重叠如何解决

• 第一步调整绘图边距，预留底部图例空间：在绘制主图前运行以下代码，将底部边距从默认的5放大到8，可根据实际显示效果调整数值

par(mar = c(8, 4, 4, 2) + 0.1)

• 第二步调整图例参数，修改位置规则和偏移、尺寸：将legend位置改为bottom，新增inset参数控制向绘图区域外下方偏移，新增cex参数缩小图例文字大小，参数数值可按需调整

修改后完整的图例代码如下：

legend("bottom",
       title = "groups",
       lty = 1,
       col = c("red","gold","blue","green","black","purple","orange","pink","grey","dark blue","violet","dark red","brown","maroon"),
       legend = c("Babl","Chli","Cuaz","Frve","Juma","Pafl","Pibr","Pich","Plwr","Prgl","Quvi","Sela","Ulpa","Vaca"),
       bty = "n",
       xpd = TRUE,
       ncol = 3,
       inset = c(0, -0.25),
       cex = 0.8)

如果调整后仍有重叠，可适当增大mar的第一个数值，或者加大inset第二个参数的绝对值，直到图例和标签完全分离无重叠。

内容的提问来源于stack exchange，提问作者Kal N