Q:

ggplot : Multi variable (multiple continuous variable) plotting

A data that is deduced from a larger data using dplyr, shows me information regarding the total sales of the four quarters for the years 2013 and 2014. 
    Quarter  X2013       X2014    Total.Result
1   Qtr 1   77282.13    66421.10    143703.2
2   Qtr 2   69174.64    76480.13    145654.8
3   Qtr 3   65238.47    79081.74    144320.2
4   Qtr 4   65429.73    109738.82   175168.5

I wish to plot a bargraph for the following using ggplot by comparing the two years on the bars and for such bar-groups for the each of the quarters like shown below. (output from MS Excel)

The ggplot statement that I used is as shown below (I may be wrong)
ggplot(qtr2, aes(x=as.factor(Quarter),fill=c(X2013,X2014))) +
    geom_bar(position="dodge")

and I get an error
Error: Aesthetics must either be length one, or the same length as the dataProblems:as.factor(Quarter)

A:

You need to bring your data into the long format for ggplot:
require(ggplot2)
require(reshape2)
df <- read.table(header = TRUE, text = 'R    Quarter  X2013       X2014    Total.Result
1   Qtr 1   77282.13    66421.10    143703.2
2   Qtr 2   69174.64    76480.13    145654.8
3   Qtr 3   65238.47    79081.74    144320.2
4   Qtr 4   65429.73    109738.82   175168.5')
df$R <- NULL
head(df)

# bring to long data (1)
dfm <- melt(df, id.vars = c('Quarter', 'Total.Result'))
dfm

ggplot(dfm, aes(x = factor(Quarter), y = value, fill = variable) ) +
  geom_bar(stat="identity", position = 'dodge')

Regarding the Total Result column / bars: I don't know where this data should come from (missing?) - There is only one column, but two bars? And the values do not fit. If you tell me how to generate these, it should be no problem to plot.

