title: how to plot two variables in a bar graph plot
body: <p>i need help with plotting the dataframe below in a bargraph which i'll add as well.</p>
  
  <pre><code>      Month       Base       Advanced
     2008-01-01  20.676043   20.358472
     2008-02-01  -57.908706  -62.368464
     2008-03-01  -3.130082   -5.876791
     2008-04-01  20.844747   14.162446
     2008-05-01  39.882740   42.315828
     2008-06-01  -12.802920  -13.333419
     2008-07-01  -49.299693  -39.843041
     2008-08-01  -4.563942   10.995445
     2008-09-01  -100.018700 -77.054218
     2008-10-01  -42.056913 -30.485998
  </code></pre>
  
  <p>My current code which isnt working great:</p>
  
  <pre><code>ggplot(ResidualsDataFrame,aes(x=Base,y=Advanced,fill=factor(Month)))+
  geom_bar(stat="identity",position="dodge")+
  scale_fill_discrete(name="Forecast",breaks=c(1, 2),     
  labels=c("Base", "Advanced"))+
  xlab("Months")+ylab("Forecast Error")
  </code></pre>
  
  <p>This is what I'm trying to make. 
  Any help is kindly appreciated.</p>
  
  <p><img src="https://i.stack.imgur.com/PDAFy.jpg" alt="Bar Graph Example"></p>