How to get a barplot with several variables side by side grouped by a factor

Question

I have a dataset which looks like this one below  I am trying to make a barplot with the grouping variable gender  with all the variables side by side on the x axis  grouped by gender as filler with different colors   and mean values of variables on the y axis  which basically represents percentages   tea                coke            beer             water           gender 14 55              26 50793651     22 53968254      40              1 24 92997199        24 50980392     26 05042017      24 50980393     2 23 03732304        30 63063063     25 41827542      20 91377091     1    225 51781276       24 6064623      24 85501243      50 80645161     1 24 53662842        26 03706973     25 24271845      24 18358341     2      In the end I want to get a barplot like this    any suggestions how to do that  I made some searches but I only find examples for factors on the x axis  not variables grouped by a factor  any help will be appreciated

User · Answer

You can plot the means without resorting to external calculations and additional tables using stat_summary(...). In fact, stat_summary(...) was designed for exactly what you are doing.

library(ggplot2)
library(reshape2)            # for melt(...)
gg <- melt(df,id="gender")   # df is your original table
ggplot(gg, aes(x=variable, y=value, fill=factor(gender))) + 
  stat_summary(fun.y=mean, geom="bar",position=position_dodge(1)) + 
  scale_color_discrete("Gender")
  stat_summary(fun.ymin=min,fun.ymax=max,geom="errorbar",
               color="grey80",position=position_dodge(1), width=.2)

To add "error bars" you cna also use stat_summary(...) (here, I'm using the min and max value rather than sd because you have so little data).

ggplot(gg, aes(x=variable, y=value, fill=factor(gender))) + 
  stat_summary(fun.y=mean, geom="bar",position=position_dodge(1)) + 
  stat_summary(fun.ymin=min,fun.ymax=max,geom="errorbar",
               color="grey40",position=position_dodge(1), width=.2) +
  scale_fill_discrete("Gender")

User · Answer

Using reshape2 and dplyr  Your data   df  lt - read table text   tea                coke            beer             water           gender 14 55              26 50793651     22 53968254      40              1 24 92997199        24 50980392     26 05042017      24 50980393     2 23 03732304        30 63063063     25 41827542      20 91377091     1    225 51781276       24 6064623      24 85501243      50 80645161     1 24 53662842        26 03706973     25 24271845      24 18358341     2   header TRUE    Getting data into correct form   library reshape2  library dplyr  df melt  lt - melt df  id  gender   bar  lt - group by df melt  variable  gender    summarise mean mean value     Plotting   library ggplot2  ggplot bar  aes x variable  y mean  fill factor gender       geom bar position  dodge   stat  identity

User · Answer

You can use aggregate to calculate the means   means lt -aggregate df by list df gender  mean  Group 1      tea     coke     beer    water gender 1       1 87 70171 27 24834 24 27099 37 24007      1 2       2 24 73330 25 27344 25 64657 24 34669      2   Get rid of the Group 1 column  means lt -means  2 length means     Then you have reformat the data to be in long format   library reshape2  means long lt -melt means id vars  gender     gender variable    value 1      1      tea 87 70171 2      2      tea 24 73330 3      1     coke 27 24834 4      2     coke 25 27344 5      1     beer 24 27099 6      2     beer 25 64657 7      1    water 37 24007 8      2    water 24 34669   Finally  you can use ggplot2 to create your plot   library ggplot2  ggplot means long aes x variable y value fill factor gender       geom bar stat  identity  position  dodge      scale fill discrete name  Gender                         breaks c 1  2                         labels c  Male    Female       xlab  Beverage   ylab  Mean Percentage

[r] How to get a barplot with several variables side by side grouped by a factor

Examples related to r

Examples related to ggplot2

Examples related to bar-chart