Controlling legend labels for a plot with color and linetype aesthetic attributes

Question

I would like to plot four lines with the legend label AND color dictated by unique values in the column, "Color_Group" and the linetype by "Line_Type_Group". Here is code needed to make the data frame, and the data frame itself.

data <- data.frame("x"=c(1,2,1,2,1,2,1,2),
                "y"=1:8,
                "Color_Group"=c("A","A","A","A","B","B","C","C"),
                "Line_Type_Group"=c(1,1,2,2,2,2,1,1),
                "Group"=c("A1","A1","A2","A2","B2","B2","C1","C1"),
                stringsAsFactors=F)

> data
  x y Color_Group Line_Type_Group  Group
  1 1           A               1     A1
  2 2           A               1     A1
  1 3           A               2     A2
  2 4           A               2     A2
  1 5           B               2     B2
  2 6           B               2     B2
  1 7           C               1     C1
  2 8           C               1     C1

The main "Group" column is the result of pasting the color and linetype columns together, and it represents the id for each line. In order to get one legend, I initially map the color and linetype attributes to this "Group" column. Below is what I want the plot to look like.

Desired Plot

Attempt

For simplicity's sake, I'm recreating the data frame to include columns with the literal color and linetype values.

data <- data.frame("x"=c(1,2,1,2,1,2,1,2),
                "y"=1:8,"Color_Group"=c("A","A","A","A","B","B","C","C"),
                "Color"=c(rep("red",4),"blue","blue","green","green"),
                "Line_Type_Group"=c(1,1,2,2,2,2,1,1),
                "Line_Type"=c("solid","solid","dashed","dashed","dashed","dashed","solid","solid"),
                "Group"=c("A1","A1","A2","A2","B2","B2","C1","C1"),
                stringsAsFactors = F)

> data
  x y Color_Group Color Line_Type_Group Line_Type Group
  1 1           A   red               1     solid    A1
  2 2           A   red               1     solid    A1
  1 3           A   red               2    dashed    A2
  2 4           A   red               2    dashed    A2
  1 5           B  blue               2    dashed    B2
  2 6           B  blue               2    dashed    B2
  1 7           C green               1     solid    C1
  2 8           C green               1     solid    C1  


line_type_group <- data$Line_Type
color_group <- data$Color
names(line_type_group) <- data$Group
names(color_group) <- data$Group
labels <- data$Color_Group
names(labels) <- data$Group
#Both attempts at setting labels variable yields plot below
#labels <- c("A","A","B","C")

g <- ggplot(data,aes(x=x,y=y,colour=Group,linetype=Group))+geom_line()
g + scale_colour_manual(name="Legend",values=color_group,labels=labels) +
    scale_linetype_manual(name="Legend",values =line_type_group,labels=labels)

Answer 1

You could work around this by suppressing the linetype legend after changing the values to what you want and then "manually" setting the linetypes in the colour legend using override.aes.

ggplot(data,aes(x=x, y=y, colour=Group, linetype=Group))+
    geom_line() + 
    scale_colour_manual(values = color_group, labels = labels) +
    scale_linetype_manual(values = line_type_group, guide = "none") +
    guides(colour = guide_legend(override.aes = list(linetype = c(1, 2, 2, 1))))

Answer 2

this give you almost what you want

g <- ggplot(data,aes(x=x,y=y,colour=Group,linetype=Group))+geom_line()
g + scale_colour_manual(name="Legend",values=c("red", "red", "blue", "green"), labels = c("A1", "A2", "B", "C")) +scale_linetype_manual(name="Legend",values=c("solid", "dashed", "dashed", "solid"), labels = c("A1", "A2", "B", "C"))
#
g