使用foreach实现基于级别的子集

我想保存一系列基本上如下所示的图形：

这是由以下代码生成的：

# orange is pre, red is intra, green is post
df$Month <- as.Date(df$activityDate)
ggplot(df, aes(x= Month, y= level)) + 
geom_jitter(colour= ifelse(df$phase == "post", 'springgreen4',
                        ifelse(df$phase == "pre", 'orange1', 'red3')),
                            size= 3, shape= 19, height=0.20, alpha = 0.6) +
theme_bw() +
    labs(title="EPA Levels Over Time", x= "Date", y= "EPA Level") +
    scale_x_date(labels= date_format("%m-%Y")) +
# main title
  theme(plot.title = element_text(face= 'bold', size=18)) +
# x axis title 
  theme(axis.title.x = element_text(face= 'bold', size=14)) +
# y axis title
  theme(axis.title.y = element_text(face= 'bold', size=14)) +
# x axis tick mark labels
  theme(axis.text.x= element_text(hjust = 1, angle = 45, face= 'bold', size=10)) +
# y axis tick mark labels
  theme(axis.text.y = element_text(face= 'bold', size=12)) +
    facet_grid(~ epa) # show each epa

#橙色为前置，红色为内部，绿色为后置
df$Month在没有看到实际数据的情况下很难判断。您能从
geom\u jitter
中删除颜色吗？我想这和颜色有关。我认为你正在设置许多颜色。您可以尝试
geom\u jitter（aes（color=phase））
并添加
scale\u color\u手动（值=c（“pre”=“orange”，“intra”=“red”，“post”=“springgreen4”）
。是的，从geom\u jitter中删除color=可以解决问题，但是我还应该如何进行条件点着色？在循环中设置颜色时，您需要参考
dfgraph
而不是
df
。一个更好的方法是按照@ricoderks所建议的美学方法绘制颜色图。
foreach(i=levels(df$resident)) %do% {
  dfgraph <- df[df$resident==i,]
ggplot(dfgraph, aes(x= Month, y= level)) + 
geom_jitter(colour= ifelse(df$phase == "post", 'springgreen4',
                        ifelse(df$phase == "pre", 'orange1', 'red3')),
                            size= 3, shape= 19, height=0.20, alpha = 0.6) +
theme_bw() +
    labs(title="EPA Levels Over Time", x= "Date", y= "EPA Level") +
    scale_x_date(labels= date_format("%m-%Y")) +
# main title
  theme(plot.title = element_text(face= 'bold', size=18)) +
# x axis title 
  theme(axis.title.x = element_text(face= 'bold', size=14)) +
# y axis title
  theme(axis.title.y = element_text(face= 'bold', size=14)) +
# x axis tick mark labels
  theme(axis.text.x= element_text(hjust = 1, angle = 45, face= 'bold', size=10)) +
# y axis tick mark labels
  theme(axis.text.y = element_text(face= 'bold', size=12)) +
    facet_grid(~ epa) # show each epa
  ggsave(filename = paste0(i, ".png"))
  }