R: How to have conditional geom_rect highlights for only a specific string in a column of strings fo-CodePudding

I have the following dataframe and scatterplot

df <-
    setNames(data.frame(
        as.POSIXct(
            c(
            "2022-07-29 00:00:00",
            "2022-07-29 00:00:05",
            "2022-07-29 00:05:00",
            "2022-07-29 00:05:05",
            "2022-07-29 00:10:00",
            "2022-07-29 00:15:00",
            "2022-07-29 00:20:00",
            "2022-07-29 00:20:05"
            )),
        c(1, 2, 3, 4, 5, 6, 7, 8),
        c(0.8, 2.1, 2.5, 4.1, 5, 6.1, 6.9, 8.1),
        c("a", "a", "b", "b", "b", "b", "b", "c")
    ),
    c("timeStamp", "value1", "value2", "text"))

df %>% ggplot(aes(timeStamp, value1, color =text))   geom_point()

I want to highlight on the graph the areas where a specific text value is in the same row as the data. for example, if we want to highlight with geom_rect the b values, here is my attempt:

df %>% ggplot(aes(timeStamp, value1, color =text))   geom_point()  
   geom_rect(xmin= -00:00:05, xmax=  00:00:05, ymin=-0.2, ymax=0.2, color = ifelse(text=="b", 
  "yellow", ""), alpha =0.5)

I know this doesnt work but can't seem to find a solution. Also, I know it may seem more prudent to simply change the size of the data points and color of the data points but I need the rectangles for a specific analysis with a much larger dataset. Thank you!

CodePudding user response：

You can try this,

df %>% ggplot(aes(timeStamp, value1, color =text))  
       geom_point()  
       annotate("rect", 
           xmin= min(df$timeStamp[df$text=="b"]), 
           xmax= max(df$timeStamp[df$text=="b"]), 
           ymin= min(df$value1[df$text=="b"]), 
           ymax= max(df$value1[df$text=="b"]),
           color = "yellow",fill="yellow", alpha = 0.2 ) 
       theme_bw()

or using geom_rect

df %>% ggplot(aes(timeStamp, value1, color =text))  
    geom_point()   geom_rect(data = subset(df,text=="b"),
          xmin= df$timeStamp[df$text=="b"] 60,
          xmax= df$timeStamp[df$text=="b"]-60,
          ymin= df$value1[df$text=="b"] 1,
          ymax= df$value1[df$text=="b"]-1,
          color = NA, fill="yellow", alpha = 0.2) 
    theme_light()