title: ggplot does not process theme_bw()
body: <p>I am trying to make a histogram of brain activation across two different conditions, and I have the main plot working. However, I would like to change the orientation of the labels of the x-axis, as well as the legend labels and the font.. All of these pass through the theme() argument, but for some reason, my plot does not seem to take them in to account.</p>
  
  <pre><code>     x = colnames(data[,c(3:8,12:21)])
       y1 = meand3h
       y2 = meand5h
  
       to_plot &lt;- data.frame(x=x,y1=y1,y2=y2) 
       melted&lt;-melt(to_plot, id="x")
  
  
       p&lt;-ggplot(melted,aes(x=x,y=value,fill=variable))
  
       p
       + scale_shape_discrete(name="Group",labels=c("Three days","Five days")) 
       + geom_bar(stat="identity", alpha=1) 
       + labs(y = "Level of Activation")
       + labs(title = "Activation of Brain Areas After Training")    
       + theme_bw(base_size = 12, base_family = "Times") 
       + theme(axis.title.x = element_text(angle=180))
  </code></pre>
  
  <p>Can anyone help me fix this?</p>