Change symbol and fill in scale_size_continuous()

January 26, 2023

I am trying to change the symbol type (to triangle), it’s fill (to NA), and border (to black) for scale_size_continuous() in ggplot2. I would like to keep the two legends. I can’t seem to figure it out. Here is some example data:

data <- structure(list(date = structure(c(1431388800, 1444780800, 1456876800, 
                                              1469145600, 1469664000, 1425081600, 1445299200, 1488758400, 1524960000, 
                                              1454544000, 1540512000, 1429228800, 1481587200, 1526688000, 1445904000, 
                                              1498348800, 1464825600, 1451174400, 1450310400, 1539216000, 1528934400, 
                                              1525996800, 1465084800, 1531180800), class = c("POSIXct", "POSIXt"
                                              ), tzone = "UTC"), cnt1 = c(76, 140, 99, 10, 123, 124, 160, 58, 
                                                                          47, 43, 86, 112, 26, 123, 111, 49, 65, 93, 174, 49, 5, 16, 84, 
                                                                          4), cnt2 = c(111, 200, 550, 73, 123, 184, 166, 131, 189, 136, 
                                                                                       250, 195, 26, 154, 125, 100, 168, 151, 255, 49, 200, 144, 177, 
                                                                                       4), per = c(68.4684684684685, 70, 18, 13.6986301369863, 100, 
                                                                                                   67.3913043478261, 96.3855421686747, 44.2748091603053, 24.8677248677249, 
                                                                                                   31.6176470588235, 34.4, 57.4358974358974, 100, 79.8701298701299, 
                                                                                                   88.8, 49, 38.6904761904762, 61.5894039735099, 68.2352941176471, 
                                                                                                   100, 2.5, 11.1111111111111, 47.4576271186441, 100), status = c("A", 
                                                                                                                                                                  "B", "C", "C", "B", "B", "B", "A", "A", "A", "C", "C", "C", "A", 
                                                                                                                                                                  "B", "C", "B", "C", "A", "A", "A", "B", "B", "B"), category = c("CAT3", 
                                                                                                                                                                                                                                  "CAT1", "CAT3", "CAT2", "CAT1", "CAT1", "CAT1", "CAT3", "CAT2", 
                                                                                                                                                                                                                                  "CAT3", "CAT2", "CAT1", "CAT1", "CAT1", "CAT2", "CAT2", "CAT1", 
                                                                                                                                                                                                                                  "CAT1", "CAT1", "CAT1", "CAT3", "CAT3", "CAT3", "CAT1")), .Names = c("date", 
                                                                                                                                                                                                                                                                                                       "cnt1", "cnt2", "per", "status", "category"), row.names = c(NA, 
                                                                                                                                                                                                                                                                                                                                                                   -24L), class = c("tbl_df", "tbl", "data.frame"))

Here is the legend item that I’m trying to change (to upside triangles with no fill):

Here is my plotting function:

ggplot(data, aes(x=date, y=cnt2)) + 
      scale_y_log10(breaks=c(1,10,100,1000,5000)) +
      geom_point(aes(fill=category,col=category, size=per, shape=category), alpha=0.7)+
      scale_color_manual(name = "",values=c("CAT1"="black","CAT2"="black","CAT3"="black")) + 
      scale_shape_manual(name = "",values=c('CAT1'=24, 'CAT2'=25, 'CAT3'=23))+
      scale_fill_manual(name = "",values=c("CAT1"="blue","CAT2"="red","CAT3"="green"))+
      scale_size_continuous(trans="sqrt",range = c(1, 5),breaks=c(5,10,25,50,75,100))

>Solution :

Add in guides(size = guide_legend(override.aes = list(shape = 25))) to manually set the shape in the legend:

library(ggplot2)

ggplot(data, aes(x=date, y=cnt2)) + 
  scale_y_log10(breaks=c(1,10,100,1000,5000)) +
  geom_point(aes(fill=category,col=category, size=per, shape=category), alpha=0.7)+
  scale_color_manual(name = "",values=c("CAT1"="black","CAT2"="black","CAT3"="black")) + 
  scale_shape_manual(name = "",values=c('CAT1'=24, 'CAT2'=25, 'CAT3'=23))+
  scale_fill_manual(name = "",values=c("CAT1"="blue","CAT2"="red","CAT3"="green"))+
  scale_size_continuous(trans="sqrt",range = c(1, 5),breaks=c(5,10,25,50,75,100)) +
  guides(size = guide_legend(override.aes = list(shape = 25)))

Or scale_size_continuous(..., guide = guide_legend(override.aes = list(shape = 25))) is the other possible place to amend this within the scale_ function call.