ggplot2 的小提琴图与 x 轴上的数据集的顺序不同

I created the using below code, But on the x-axis, Models name are not in order as in the data set (i.e. "Observed", "SVM", "Grid_SVM", "MARS", "Grid_Mars", "RF", "Grid_RF"). Where the edit is required in the code?

ggplot(df1, aes(x = Model, y = Pb), cex.lab = 18, cex.axis=18) +
  geom_violin(trim=FALSE, fill = "palegreen") +
  geom_boxplot(width = .12, fill = "orange", outlier.color = "orange", outlier.size = 2) + 
  labs(title = "Pb Adsorption distribution by Models over testing phase") + xlab("Models") + ylab("Pb Adsorption distribution")+ theme_classic() +
  theme(
  plot.title = element_text(size = 12, colour = "black", face = "bold"), #for Main Title
  axis.title.x = element_text(size = 12, colour = "black", face = "bold"), #for axix title
  axis.title.y = element_text(size = 12, colour = "black", face = "bold"),
  axis.text.x = element_text(face="bold", color="darkblue", size=12, angle=0), #for axis tick
  axis.text.y = element_text(face="bold", color="black", size=12, angle=0))

默认情况下，ggplot2 按字母顺序绘制字符向量。要对绘图放置指定的顺序，只需使用 dplyr 并将列创建为factor()并指定您想要的级别。然后 ggplot2 应该按照你想要的方式绘制它。

Edit #1一种方法是修改df1数据框与 ggplot2 命令字符串分开。你可以这样做

df1 <- df1 %>%
  mutate( Model=factor(Model,levels=c("Observed", "SVM", "Grid_SVM", "MARS", "Grid_Mars", "RF", "Grid_RF")) )

然后调用您上面发布的 ggplot2 命令字符串。

Edit #2（来自下面的评论）

如果您想通过管道传输所有内容并一次性完成所有操作，请尝试

df1 %>%
  mutate( Model=factor(Model,levels=c("Observed", "SVM", "Grid_SVM", "MARS", "Grid_Mars", "RF", "Grid_RF")) ) %>%
  ggplot( aes(x = Model, y = Pb), cex.lab = 18, cex.axis=18) +
  geom_violin(trim=FALSE, fill = "palegreen") +
  geom_boxplot(width = .12, fill = "orange", outlier.color = "orange", outlier.size = 2) + 
  labs(title = "Pb Adsorption distribution by Models over testing phase") + xlab("Models") + ylab("Pb Adsorption distribution")+ theme_classic() +
  theme(
  plot.title = element_text(size = 12, colour = "black", face = "bold"), #for Main Title
  axis.title.x = element_text(size = 12, colour = "black", face = "bold"), #for axix title
  axis.title.y = element_text(size = 12, colour = "black", face = "bold"),
  axis.text.x = element_text(face="bold", color="darkblue", size=12, angle=0), #for axis tick
  axis.text.y = element_text(face="bold", color="black", size=12, angle=0))

最初的建议是覆盖数据。然后在新的链中生成绘图。

df1 <- df1 %>%
  mutate( Model=factor(Model,levels=c("Observed", "SVM", "Grid_SVM", "MARS", "Grid_Mars", "RF", "Grid_RF")) )

ggplot( df1, aes(x = Model, y = Pb), cex.lab = 18, cex.axis=18) +
  geom_violin(trim=FALSE, fill = "palegreen") +
  geom_boxplot(width = .12, fill = "orange", outlier.color = "orange", outlier.size = 2) + 
  labs(title = "Pb Adsorption distribution by Models over testing phase") + xlab("Models") + ylab("Pb Adsorption distribution")+ theme_classic() +
  theme(
  plot.title = element_text(size = 12, colour = "black", face = "bold"), #for Main Title
  axis.title.x = element_text(size = 12, colour = "black", face = "bold"), #for axix title
  axis.title.y = element_text(size = 12, colour = "black", face = "bold"),
  axis.text.x = element_text(face="bold", color="darkblue", size=12, angle=0), #for axis tick
  axis.text.y = element_text(face="bold", color="black", size=12, angle=0))

以上任何一个都可以。