CODEWITHSUNDEEP
rggplot2shiny
Tomas H
Tomas H

Reputation: 713

Pairing colors to factors in ggplot2

I have a variable Channel which is factor with levels A,B,C. If you run my shiny up level A is red points level B green points and level C blue points. When I uncheck A level to make it disspear colous for B and C change and that is what I want to prevents. So every level should have it's colour. I tried to play around a bit with scale manual etc but no success.

########### UI.R
library(shiny)

shinyUI(fluidPage(
    titlePanel("Hello Shiny!"),
    sidebarLayout(
        sidebarPanel(
            checkboxGroupInput(inputId="check1_1", label="Select channel", choices=c("a","b","c"),
                               selected=c("a","b","c"))
        ),

        mainPanel(
            plotOutput("myplot")
        )
    )
))

########## Server.R
shinyServer(function(input, output) {

df<-data.frame(Channel=sample(letters[1:3],100,replace = TRUE),
                        x=runif(100),
                        y=runif(100))

df1<-reactive({

    y<-as.factor(input$check1_1)
    df1<-df[which(df$Channel %in% y), ]
}) 
output$myplot<-renderPlot({
    ggplot(df1(),aes(x = x,y = y,colour=Channel))+geom_point(size=6)
})  


})

Upvotes: 2

Views: 408

Answers (1)

eipi10
eipi10

Reputation: 93811

You can just add + scale_color_discrete(drop=FALSE) to your ggplot code. This will work regardless of which rows are removed from the data, so long as the underlying levels of the factor don't change.

Upvotes: 2

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