Qfyilyi

I created a plot that visualizes data as I intended with this code:

library(ggplot2)



data = data.frame()



for (x in seq(1,10)){

data = rbind(data, data.frame(x = rnorm(10, sd=0.1) + x, y = seq(10,1), group = x,

                              category = c(rep("a", 3), rep("b", 3), rep("c", 3), "d")))

}



data$group = as.factor(data$group)



ggplot() +

  theme(legend.position="none", panel.grid.major = element_blank(), panel.grid.minor = element_blank(),

        panel.background = element_blank(), axis.title.y = element_blank(), axis.ticks.y=element_blank(),

        axis.text.y=element_blank()) +

  geom_path(data = data, mapping = aes(x=x, y=y, col= group, alpha=0.5)) +

  geom_point(data = data, mapping = aes(x=x, y=y, col= group))

I now want to add a bar at the side that explains the grouping defined in the category column. A legend or labels of this category should also be shown.

First generate a category vector

# list the categories by their freqencies

cgy <- as.data.frame(table(data$category), stringsAsFactors=FALSE)

# convert the values so that a "0" category finds place

# the "0" category is needed because groups starting at "1"

cgy$Freq <- cgy$Freq/10*9

cgy <- rbind(c(0, 10), cgy)  # bind a "0" category 

# get the desired vector

cgy.v <- unlist(sapply(1:nrow(cgy), function(x) rep(cgy[x, 1], cgy[x, 2])))

rm(cgy)  # clean up

Your plot

p <- ggplot() +

  theme(legend.position="none", 

        panel.grid.major=element_blank(), 

        panel.grid.minor=element_blank(),

        panel.background=element_blank(), 

        axis.title.y=element_blank(), 

        axis.ticks.y=element_blank(),

        axis.text.y=element_blank()) +

  geom_path(data=data, mapping=aes(x=x, y=y, col= group, alpha=0.5)) +

  geom_point(data=data, mapping=aes(x=x, y=y, col= group))

Add

p + geom_bar(data=data, aes(0, y = as.integer(category)/22),

             fill = factor(sort(cgy.v), 

                           labels=(c("white", "blue", "orange", "yellow", "green"))),

             stat = "identity") +

# the labels: 

geom_text(aes(x=0, 

              y=c(as.integer(table(cgy.v)))/10, 

              label=c("",sort(unique(cgy.v))[-1])), 

          size=4, 

          color="black", position=position_stack(vjust=.5))

Yielding