Change colors boxplots by groups ggplot2 - r

Question

I have this boxplots in shiny and I would like to change colors with vector "cols", change the order of the legend and rename x axis. Do you know the best way to do that? I have tried with scale_fill_discrete and scale_x_discrete and it didn't work.
Thanks!
dados7 <- reactive({
dataset1() %>% filter(variable==input$frame) %>%
rename( var8 = regiao, var9 = imp, var10 = metodo)
})
cols<-c("green","orange", "red", "blue","pink","salmon","black")
renderPlotly({
title3<-paste(input$frame, "por região")
if (input$frame=="Taxa_Natalidade")
r<- dados7() %>%
ggplot(aes(x = var10, y = var9)) +
geom_boxplot(aes(fill = var10), position = position_dodge(0.9)) +
facet_wrap(vars(var8))
r
})

Answer 1

have you tried: scale_fill_manual(values=c("blue","green", etc...)
Should work

Answer 2

Your question is actually a few parts in one. You are looking to:
Change the colors for fill to a specific palette.
Change the order of the legend
Rename the x axis.
The easy one is #3. All you have to do is rename the x axis by specifying in labs(x="new name for your axis"). If you are changing the x axis scale with a scale_x_* function, you'll want to rename within that function, since labs() is just a convenience function for various scale_*_(name=...) functions.
Now, for the other questions, it's not possible to provide a good answer without a good dataset, so I'm going to make up some data using the iris dataset.
set.seed(123)
df <- iris
df$rand_label <- sample(paste0('Type',1:3), nrow(df), replace=TRUE)
Now, see a resulting boxplot to be used to demonstrate:
p <- ggplot(df, aes(x=Species, y=Sepal.Length, fill=rand_label)) +
geom_boxplot() + theme_classic()
p
Changing Colors
To change fill colors, you only need to specify via scale_fill_manual() by passing the list of colors to the values= argument. Caution: you must supply a list of colors that matches the number of levels in the factor used to define fill. In this example, df$rand_label contains 3 levels, so we need to supply a vector of 3 colors:
cols <- c('orange','pink','gray20')
p + scale_fill_manual(values=cols)
If you want to specify to which level the colors are assigned, instead of passing a character vector you can pass either a named vector or a list of "label name" = "color name". Note that order doesn't matter here, since everything is explicitly defined:
cols1 <- c('Type3'='orange','Type2'='pink','Type1'='gray20')
p + scale_fill_manual(values=cols1)
Changing Ordering
You can change the order of the fill legend in two different ways: (1) change the order of the legend and the positioning on the plot, and (2) just change the order of the items in the legend itself. First, I'll show you the #1 case (changing order of legend and positioning on the plot).
Change order of legend and order on plot
Changing both is more typically what you will do, since we often like the order things appear in the legend to match the order in which they appear on the plot. The best way to do this is to refactor the column in question and pass an ordered vector to levels= matching the order you want. You then need to call ggplot() again with your re-leveled factor:
df$rand_label <- factor(df$rand_label, levels=c('Type3','Type1','Type2'))
ggplot(df, aes(x=Species, y=Sepal.Length, fill=rand_label)) +
geom_boxplot() + theme_classic() + scale_fill_manual(values=cols)
Note that the order of the colors is still applied the same, but the order of the items is different in the plot. The order in which the items appear in the legend is also different.
Change only order in the legend
If you want to adjust the order of items as they appear in the legend, you can use the breaks= argument within scale_fill_manual() to define the order in which the items appear. In this case, we can use this to return the levels to their original order in the plot above, but retain the mixed up ordering we defined by releveling the factor. Also note that since we're just passing cols and not the named vector cols1, the colors are applied according to how the levels appear in the legend (not the way in which they are ordered in the factor):
df$rand_label <- factor(df$rand_label, levels=c('Type3','Type1','Type2'))
ggplot(df, aes(x=Species, y=Sepal.Length, fill=rand_label)) +
geom_boxplot() + theme_classic() +
scale_fill_manual(values=cols, breaks=c('Type1','Type2','Type3'))
You can also use a similar strategy to reorder the x axis: in this case, you would refactor df$Species and set the levels= according to your preferred order.