How do I set the color of a single line using ggplot

Question

df<-data.frame(adjuster=c(\"Mary\",\"Mary\",\"Bob\",\"Bob\",\"Mary\"), 
           date=as.Date(c(\"2012-1-1\",\"2012-2-1\",\"2012-3-1\",\"2012-4-1\",\"2012-5-1\")),          


        

Answer 1

This way Paid column is added as a separate layer, but that means it's not in the legend. I don't get why the column Paid would go in a legend with different levels of adjuster anyway. Why is that?

library(ggplot2)
df <- data.frame(adjuster=c("Mary","Mary","Bob","Bob","Mary"), 
           date=as.Date(c("2012-1-1","2012-2-1","2012-3-1","2012-4-1","2012-5-1")), 
           total=c(10,15,25,15,20), paid=c(5,5,10,10,15))

ggplot(df, aes(x=date,y=total,color=adjuster,group=1)) + 
  geom_point() +
  geom_line(aes(x=date, y=total, color=adjuster, group=1)) +
  geom_line(aes(x=date, y=paid, group=2), data=df, colour="black") +
  scale_color_discrete(name="Legend")