Color in legend being overwritten

Question

While different colors are shown in the plot, the legend shows only one color. My objective is to show the legend as is. Also, I am NOT looking to use shapes between 21 and 25. I want to use a different shape e.g. Shape = 2.

Here's the source code:

#catsM dataset is in MASS package that is shipped by CRAN
     testM<-catsM
     testM[1:10,"Sex"] <- "F"
     ggplot(testM,aes(Bwt,Hwt)) +
      geom_point(aes(color=Sex), shape = 2) + 
        geom_smooth(method = "glm", se = FALSE, 
                    aes(linetype = "glm line"), color = "red") + 
        geom_smooth(method = "lm", span = 0.5, 
                    aes(linetype = "lm line"), color = "yellow") + 
        scale_color_manual(values = c("magenta","black"))

Here's the output. We can see that the color code of the second line lm overrides the red color of glm. Is there any fix for this? I'd appreciate your thoughts.

I am posting dput():

dput(catsM)
structure(list(Sex = structure(c(2L, 2L, 2L, 2L, 2L, 2L, 2L, 
2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L), .Label = c("F", "M"), class = "factor"), 
    Bwt = c(2, 2, 2.1, 2.2, 2.2, 2.2, 2.2, 2.2, 2.2, 2.2, 2.2, 
    2.3, 2.4, 2.4, 2.4, 2.4, 2.4, 2.5, 2.5, 2.5, 2.5, 2.5, 2.5, 
    2.5, 2.5, 2.6, 2.6, 2.6, 2.6, 2.6, 2.6, 2.7, 2.7, 2.7, 2.7, 
    2.7, 2.7, 2.7, 2.7, 2.7, 2.8, 2.8, 2.8, 2.8, 2.8, 2.8, 2.8, 
    2.9, 2.9, 2.9, 2.9, 2.9, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3.1, 
    3.1, 3.1, 3.1, 3.1, 3.1, 3.2, 3.2, 3.2, 3.2, 3.2, 3.2, 3.3, 
    3.3, 3.3, 3.3, 3.3, 3.4, 3.4, 3.4, 3.4, 3.4, 3.5, 3.5, 3.5, 
    3.5, 3.5, 3.6, 3.6, 3.6, 3.6, 3.7, 3.8, 3.8, 3.9, 3.9), Hwt = c(6.5, 
    6.5, 10.1, 7.2, 7.6, 7.9, 8.5, 9.1, 9.6, 9.6, 10.7, 9.6, 
    7.3, 7.9, 7.9, 9.1, 9.3, 7.9, 8.6, 8.8, 8.8, 9.3, 11, 12.7, 
    12.7, 7.7, 8.3, 9.4, 9.4, 10.5, 11.5, 8, 9, 9.6, 9.6, 9.8, 
    10.4, 11.1, 12, 12.5, 9.1, 10, 10.2, 11.4, 12, 13.3, 13.5, 
    9.4, 10.1, 10.6, 11.3, 11.8, 10, 10.4, 10.6, 11.6, 12.2, 
    12.4, 12.7, 13.3, 13.8, 9.9, 11.5, 12.1, 12.5, 13, 14.3, 
    11.6, 11.9, 12.3, 13, 13.5, 13.6, 11.5, 12, 14.1, 14.9, 15.4, 
    11.2, 12.2, 12.4, 12.8, 14.4, 11.7, 12.9, 15.6, 15.7, 17.2, 
    11.8, 13.3, 14.8, 15, 11, 14.8, 16.8, 14.4, 20.5)), .Names = c("Sex", 
"Bwt", "Hwt"), row.names = c("1", "2", "3", "4", "5", "6", "7", 
"8", "9", "10", "11", "12", "13", "14", "15", "16", "17", "18", 
"19", "20", "21", "22", "23", "24", "25", "26", "27", "28", "29", 
"30", "31", "32", "33", "34", "35", "36", "37", "38", "39", "40", 
"41", "42", "43", "44", "45", "46", "47", "48", "49", "50", "51", 
"52", "53", "54", "55", "56", "57", "58", "59", "60", "61", "62", 
"63", "64", "65", "66", "67", "68", "69", "70", "71", "72", "73", 
"74", "75", "76", "77", "78", "79", "80", "81", "82", "83", "84", 
"85", "86", "87", "88", "89", "90", "91", "92", "93", "94", "95", 
"96", "97"), class = "data.frame")

I get a warning message when I try `data('catsM', package="MASS")` — IRTFM, Aug 27 '16 at 07:48
@42- Sorry about the warning issue. I am not sure why I am not getting it. So, I have added dput(). — watchtower, Aug 27 '16 at 07:55
@42- try `data('cats', package = 'MASS')`. catsM didn't worked for me either, but MASS documentation now points toward 'cats' rather than 'catsM'. — Pj_, Aug 27 '16 at 09:37
If you want colour in a legend, you have to include color inside `aes`thetics. But then you will have two color mappings: linetype and sex. `ggplot` does not allow this. To get round the problem, use a hollow point for the sex legend, and use `fill=Sex` in place of `color=Sex`. See the answer to your [earlier question](http://stackoverflow.com/questions/39171511/displaying-proper-colors-in-legend-for-multiple-layers). — Sandy Muspratt, Aug 27 '16 at 09:44
Sandy Muspratt I had no intentions to double-post. I think I have mentioned that I want the shape to be not equal 21. Unfortunately, this doesn't help me.....This is again quick-fix and not a programmatic solution for non-fillable shapes (i.e. shapes outside the range 21 and 25), something I was looking for....I hope you understand... — watchtower, Aug 27 '16 at 10:52

score 3 · Accepted Answer · answered Aug 27 '16 at 12:18

I still haven't fully grasped all the quirks of ggplot2's legends, but if you want to force it, the guides options will allow you to manually set it:

testM<-catsM
testM[1:10,"Sex"] <- "F"
ggplot(testM,aes(Bwt,Hwt)) +
  geom_point(aes(color=Sex), shape = 2) + 
  geom_smooth(method = "glm", se = FALSE, 
          aes(linetype = "glm line"), color = "red") + 
  geom_smooth(method = "lm", span = 0.5, 
          aes(linetype = "lm line"), color = "yellow") + 
  scale_color_manual(values = c("magenta","black")) +
  guides(linetype = guide_legend(override.aes = list(color = c("red", "yellow"))))

Pj_ · Answer 2 · 2016-08-27T11:28:09.167

0

For discrete variables mapping aesthetics to shape is another option. Not sure of how good it'll be when it comes to design aesthetics and usa:

  ggplot(testM,aes(Bwt,Hwt)) +
  geom_point(aes(shape= Sex)) + 
  geom_smooth(method = "glm", se = FALSE, 
              aes(linetype = "glm", color  = 'glm')) + 
  geom_smooth(method = "lm", span = 0.5, 
              aes(linetype = "lm", color ='lm'), size = 4) + 

  scale_linetype_discrete(name = "Method") +   
  scale_color_manual(name = "Method", values = c('red', 'yellow'))

edited Aug 27 '16 at 11:28

answered Aug 27 '16 at 10:02

Pj_

824
6
15

Pj_ I think I have mentioned that I want the shape to be not equal 21. Unfortunately, this doesn't help me.....This is again quick-fix and not a programmatic solution for non-fillable shapes (i.e. shapes outside the range 21 and 25), something I was looking for... – watchtower Aug 27 '16 at 10:48
@ss0208535 Please, check and update your question and add this information that you're not really looking to use shapes inside 21 & 25. It might mislead a lot of users who are trying to help you. – Pj_ Aug 27 '16 at 11:12

Color in legend being overwritten

2 Answers2