Using a pre-defined color palette in ggplot

Question

Does anyone know how to use a pre-defined color palette in ggplot?

I have a vector of colors I would like to use:

rhg_cols <- c("#771C19", "#AA3929", "#E25033", "#F27314", "#F8A31B", 
              "#E2C59F", "#B6C5CC", "#8E9CA3", "#556670", "#000000")

But when I try to pass it to nothing happened

ggplot(mydata, aes(factor(phone_partner_products)), color = rhg_cols) +
  geom_bar()

Answer 1

You must put colour = rhg_cols inside aes(). As far as I can tell, you want to apply gradient to bars (in barplot) with factor variable on the abscissa? Then use fill - try this instead:

ggplot(mydata, aes(factor(phone_partner_products), fill = factor(phone_partner_products))) +
  geom_bar() + 
  scale_fill_manual(values = rhg_cols)

or try to achieve approximate replica with:

ggplot(mydata, aes(factor(phone_partner_products), fill = phone_partner_products))) +
  geom_bar() + 
  scale_fill_gradient(low = "#771C19", high = "#000000")

Notice that in second case a continuous variable is passed to fill aesthetics, therefore scale_fill_gradient is passed afterwards. If you pass a factor to the fill aes, you must stick with scale_fill_manual(values = rhg_cols).

Answer 2

If the colours are a palette, use scale_colour_manual:

ggplot(mydata, aes(factor(phone_partner_products), colour = colour_variable)) +
  scale_colour_manual(values = rhg_cols)

Answer 3

First add, the colours to your data set:

mydata$col <- rhg_cols

Then map colour to that column and use scale_colour_identity

ggplot(mydata, aes(factor(phone_partner_products, colour = col))) + 
  geom_bar() + 
  scale_colour_identity()

Answer 4

Since the colors you want ARE the values in the color aesthetic, what you really want is the identity scale, in this case scale_fill_identity.

 ggplot(mydata, aes(factor(phone_partner_products)), color=rhg_cols) +
   geom_bar() +
   scale_fill_identity())

Since you didn't supply data, I'm going to use a slightly different example using your color data:

 rhg_cols <- c("#771C19","#AA3929","#E25033","#F27314","#F8A31B",
               "#E2C59F","#B6C5CC","#8E9CA3","#556670","#000000")
 mydata <- sample(rhg_cols, 100, replace = TRUE)
 qplot(mydata, fill = mydata) +
   scale_fill_identity()

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note: I omitted + opts(axis.text.x=theme_text(angle=90)) for clarity in the example.