R语言plot_model绘制模型图时的图例外观自定义问询

问题背景 #

使用plot_model绘制经AIC模型选择得到的二项式广义线性混合效应模型预测图时，图例自定义遇到困难，需要完成以下4项调整：

• 将“Males”“Females”旁的线型图标改为对应颜色的填充方块
• 图例项堆叠显示（Males在上，Females在下）
• 手动移动图例至图内更靠下的位置
• 修改图例字体为Times New Roman（衬线体）并调大字号

原始代码 #

# generate break positions
breaks = c(seq(-30, 0, by=10), -2)
# and labels
labels = as.character(breaks)

plot1 <- plot_model(m2, type = "pred" ,
                    terms = c("Day [all]", "Sex"),
                    colors = c("blue", "red"),
                    ci.lvl = .95,
                    legend.title = "",
                    line.size = 1) +
  labs(x = "Days Relative to Clutch Initiation", y = "P(Attend at night)", title = NULL) +
  scale_x_continuous(expand = c(0, 0), breaks = breaks, labels = labels) + 
  scale_y_continuous(limit = c(0, 1), expand = c(0, 0)) + 
  theme_classic() + 
  theme(axis.text=element_text(size=16), 
        axis.title=element_text(size=14), 
        axis.title.x = element_text(vjust=-0.5),
        axis.title.y = element_text(vjust=2.5),
        axis.ticks.length=unit(0.1,"inch"), 
        legend.key.size = unit(1, 'cm'), 
        legend.position = "top",
        legend.justification = "left",
        plot.margin = margin(1,.5,1,1, "cm"))
plot1

修改后的代码 #

# generate break positions
breaks = c(seq(-30, 0, by=10), -2)
# and labels
labels = as.character(breaks)

plot1 <- plot_model(m2, type = "pred" ,
                    terms = c("Day [all]", "Sex"),
                    colors = c("blue", "red"),
                    ci.lvl = .95,
                    legend.title = "",
                    line.size = 1) +
  labs(x = "Days Relative to Clutch Initiation", y = "P(Attend at night)", title = NULL) +
  scale_x_continuous(expand = c(0, 0), breaks = breaks, labels = labels) + 
  scale_y_continuous(limit = c(0, 1), expand = c(0, 0)) + 
  # 调整图例符号为填充方块
  guides(color = guide_legend(override.aes = list(linetype = 0, shape = 15))) +
  theme_classic() + 
  theme(axis.text=element_text(size=16), 
        axis.title=element_text(size=14), 
        axis.title.x = element_text(vjust=-0.5),
        axis.title.y = element_text(vjust=2.5),
        axis.ticks.length=unit(0.1,"inch"), 
        legend.key.size = unit(1, 'cm'), 
        # 手动设置图例坐标（x,y范围0-1，对应图的左下角到右上角）
        legend.position = c(0.1, 0.2),
        legend.justification = "left",
        # 堆叠图例项
        legend.direction = "vertical",
        # 修改图例字体为Times New Roman并调大字号
        legend.text = element_text(family = "Times New Roman", size = 16),
        plot.margin = margin(1,.5,1,1, "cm"))
plot1

各需求对应实现说明 #

1. 将线型图标改为填充方块：
   使用guides(color = guide_legend(override.aes = list(linetype = 0, shape = 15)))，通过override.aes覆盖默认的线型符号，shape=15是实心方块，linetype=0隐藏原有线条。

2. 图例项堆叠显示：
   在theme中添加legend.direction = "vertical"，设置图例方向为垂直，实现上下堆叠。

3. 手动移动图例位置：
   将legend.position从"top"改为坐标c(0.1, 0.2)，x=0.1对应图左侧10%位置，y=0.2对应图底部20%位置，可根据实际需求调整数值。

4. 修改图例字体及字号：
   在theme中添加legend.text = element_text(family = "Times New Roman", size = 16)，指定字体为Times New Roman，同时设置字号为16（可按需调整）。

内容的提问来源于stack exchange，提问作者NeedHelpWithR