Ggplot Legend - Scale_Colour_Manual Not Working

ggplot legend not working with scale_colour_manual

You have to use show_guide=TRUE in geom_vline (defaults to FALSE):

p <- data.frame(a = runif(10, 1, 2))
ggplot(data=p, aes(x=a)) +
  geom_histogram() +
  geom_vline(aes(xintercept=mean(a), colour="mea"), show_guide=TRUE) +
  geom_vline(aes(xintercept=median(a), colour="med"), show_guide=TRUE) +
  scale_colour_manual(name="Statistic",
                      values=c("med"= "red", "mea"="green"))

scale_color_manual not working for assigning custermized color

so the fix is very easy, change scale_color_manual to scale_fill_manual

If you want colors to be the color in your color variable, just do this:

scale_fill_manual(
        breaks = c("A", "B", "C"),
        values = color)

Can't add legend to ggplot2 figure - scale_color_manual() does nothing

Move the color to your aes() and it works as expected

ggplot(data = averages, aes(x = as.integer(Deciles))) +
  scale_x_reverse(breaks = 10:1) +
  geom_line(aes(y = P_pred, color = 'darkred'), size = 2) + 
  geom_line(aes(y = P_true, color = 'darkgreen'), size = 2) +
  ylab('Probabilities') + 
  xlab('Deciles') +
  scale_color_manual(values = c('darkred','darkgreen'))

ggplot, scale_colour_manual issues

I advise you to look at how ggplot and "grammar of graphics" works (here for example: https://ramnathv.github.io/pycon2014-r/visualize/ggplot2.html).

So first you need to reshape your data to meet the requirements of ggplot:

full <- full %>% pivot_longer(cols = ends_with(c("AS","GDPpC")), 
                  names_to = c("country", ".value"),
                  names_sep="_") %>% 
rename("year" = "X1")

The resulting tibble:

    # A tibble: 50 x 4
    year country        AS GDPpC
   <dbl> <chr>       <dbl> <dbl>
 1  2011 Mali         8.29  6.73
 2  2011 Nigeria      9.32  7.82
 3  2011 Senegal      7.54  7.22
 4  2011 Afghanistan  9.94  6.38
 5  2011 Iraq         9.43  8.71
 6  2012 Mali         7.75  6.66
 7  2012 Nigeria      8.56  7.91
 8  2012 Senegal      7.70  7.18
 9  2012 Afghanistan  9.90  6.46
10  2012 Iraq         9.30  8.83
# ... with 40 more rows

Then you can use the ggplot correctly:

ggplot(data = full, mapping = aes(x = GDPpC, y = AS, col = country))+
geom_point()+
scale_color_manual(values = c("Afghanistan"="darkgreen","Iraq"="red" ,"Mali"="green", "Nigeria"="purple","Senegal"="orange"))+
geom_smooth(method = "lm")+
labs (x = "Log - GDP per Capita", y = "Log - Asylum Applications - First Time", colour = "Legend") +
theme_classic()

scale_color_manual() not working

As per the commenter above, I need to map color to a variable, the following works

ggplot(df, aes(x=cond, y=yval, color = cond)) + geom_point() + 
    scale_color_manual(values=c("red", "blue", "green"))

Scale_color_manual not working as expected

There is no reproducible data. I, therefore, created a simple data here. I also simplified the code of the OP. What is necessary here is scale_fill_manual.

mydf <- data.frame(time = letters[1:3],
                   variable = LETTERS[1:3],
                   value = runif(3, 10, 15),
                   stringsAsFactors = FALSE)

ggplot(mydf, aes(x=time, y=value, fill=variable)) +
  geom_bar(stat="identity") +
  scale_fill_manual(values=c("#a6cee3","#1f78b4","#b2df8a"))

Manual legend (scale_colour_manual) missing in plot with several aesthetics

You were almost there. The color variable inside the aes needs to be mapped to an actual colour, and the colour outside aes is unncessary.

ggplot() +
  geom_point(data=df, aes(colour='one', x=gp, y=y)) +
  geom_point(data=ds, aes(colour='two', x=gp, y=mean))+
  geom_errorbar(data=ds, aes(colour='three', x=gp, y=mean, ymin=mean-sd, ymax=mean+sd))+
  scale_color_manual(values=c(one='red', two='green', three='blue'),
                     breaks=c("one","two","three"))

---

Related Topics