drawing pyramid plot using R and ggplot2

Question

I need to draw a pyramid plot, like the one attached.

I found an example using R (but not

Answer 1

A slight tweak:

library(ggplot2)
library(plyr)
library(gridExtra)

## The Data
df <- data.frame(Type = sample(c('Male', 'Female', 'Female'), 1000, replace=TRUE),
    Age = sample(18:60, 1000, replace=TRUE))

AgesFactor <- ordered(cut(df$Age, breaks = c(18,seq(20,60,5)), 
     include.lowest = TRUE))

df$Age <- AgesFactor

## Plotting
gg <- ggplot(data = df, aes(x=Age))

gg.male <- gg + 
    geom_bar( data=subset(df,Type == 'Male'), 
        aes( y = ..count../sum(..count..), fill = Age)) +
    scale_y_continuous('', labels = scales::percent) + 
    theme(legend.position = 'none',
        axis.title.y = element_blank(),
        plot.title = element_text(size = 11.5),
        plot.margin=unit(c(0.1,0.2,0.1,-.1),"cm"),
        axis.ticks.y = element_blank(), 
        axis.text.y = theme_bw()$axis.text.y) + 
    ggtitle("Male") + 
    coord_flip()    

gg.female <-  gg + 
    geom_bar( data=subset(df,Type == 'Female'), 
        aes( y = ..count../sum(..count..), fill = Age)) +
    scale_y_continuous('', labels = scales::percent, 
                   trans = 'reverse') + 
    theme(legend.position = 'none',
        axis.text.y = element_blank(),
        axis.ticks.y = element_blank(), 
        plot.title = element_text(size = 11.5),
        plot.margin=unit(c(0.1,0,0.1,0.05),"cm")) + 
    ggtitle("Female") + 
    coord_flip() + 
    ylab("Age")

## Plutting it together
grid.arrange(gg.female,
    gg.male,
    widths=c(0.4,0.6),
    ncol=2
)

I would still want to play with margins a bit more (maybe panel.margin would help in the theme call as well).