title: title font size in ggplot2 does not change
body: <p>I know this is a very basic question, but I have trouble changing font size of axis labels in ggplot2. I used the code like below:</p>
  
  <pre><code>a &lt;- ggplot(data1,  aes(x=data2, y=data3)) + 
  geom_hline(yintercept=c(1, -1)) + 
  labs(x = data2, y = data3) + 
  theme_bw() + 
  theme(axis.text=element_text(size=10))
  </code></pre>
  
  <p>I tried to change the axis label size but they do not change.... Does anybody have suggestion?</p>