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rggplot2colorsgeom-bar

Problems with making scale_colour_manual work for my multi-factor bargraph on ggplot2 in R

I am trying to make a manual colour scale for my bar graph using plyr to summarize the data and ggplot2 to present the graph.

The data has two variables:

  1. Region (displayed on the X-axis)
  2. Genotype (displayed by the fill)

I have managed to do this already, however, I have not been able to find a way to personalize the colours - it simply gives me two randomly assigned colours.

Could someone please help me figure out what I am missing here?

I have included my code and an image of the graph below. The graph basically has the appearance I want it to, except that I can't personalize the colours.

ggplotdata <- summarySE(data, measurevar="Density", groupvars=c("Genotype", "Region"))
ggplotdata
#Plot the data
ggplotdata$Genotype <- factor(ggplotdata$Genotype, c("WT","KO"))
Mygraph <-ggplot(ggplotdata, aes(x=Region, y=Density, fill=Genotype)) + 
     geom_bar(position=position_dodge(), stat="identity",
           colour="black",
           size=.2) +
     geom_errorbar(aes(ymin=Density-se, ymax=Density+se),
           width=.2,
           position=position_dodge(.9)) +
     xlab(NULL) +
     ylab("Density (cells/mm2)") +
     scale_colour_manual(name=NULL,
           breaks=c("KO", "WT"),
           labels=c("KO", "WT"),
           values=c("#FFFFFF", "#3366FF")) +
     ggtitle("X") +
     scale_y_continuous(breaks=0:17*500) +
     theme_minimal()
Mygraph

Image of graph

Solution

  • The answer here was to use scale_fill_manual instead, thank you @dc37