title: How to increase the font size of ggtitle in ggplot2
body: <p>I would like to increase the font size of ggtitle and also the font should be bold. My code is as follows.</p>
  
  <pre><code>ggplot(df, aes(x1, y = value, colour = variable)) + 
    geom_point(size=2) + 
    ggtitle("male vs.female") +
    theme(axis.text=element_text(size=14),
          axis.title=element_text(size=14,face="bold")) + 
    theme(legend.text=element_text(size=12)) + 
    labs(x = "x axis", y = "y axis") + 
    ylim(0,100) + xlim(0,100) + 
    scale_colour_manual(values = c("red", "blue"), 
                        labels = c("male", "female"))
  </code></pre>