title: Problems saving correlation plot: dimension
body: <p>In the past I've saved <code>ggplot2</code> but the correlation plot when saved loses its dimensions and I cannot understand why. </p>
  
  <p>Let the context be this code:</p>
  
  <pre><code>cor.matrix &lt;- structure(c(1, 0.492955134006126, 0.506712693586509, 0.492955134006126, 1, 0.467841635024973, 0.506712693586509, 0.467841635024973, 1), .Dim = c(3L, 3L), .Dimnames = list(c("(0)0003", "(0)0005", "(0)0006"), c("(0)0003", "(0)0005","(0)0006")))
  
  par(oma=c(6,3,4,3), cex.axis = 0.9, mar = c(3,5,3,2), mgp = c(1,0.4,0))
  cairo_pdf("Test.pdf", 10,12)
  
  corrplot::corrplot(cor.matrix,method = "color", order = "alphabet", cl.pos = "b", tl.pos = "n")
  
  title(main="Correlation Matrix Between Bus Lines",outer=T, cex.main = 2, font.main = 3 , family = "Georgia", adj = 0.5)  
  title( sub = paste0("Alphabet Order"), outer = T, cex.sub = 1.5)
  
  dev.off()
  </code></pre>
  
  <p>The output is the following plot which I had to take a screen shot because the default format is <em>.pdf</em>.</p>
  
  <p>The problem emerges because even thought I've tried lots of variates in the <code>par</code> parameters, <code>height</code> and <code>width</code> parameters of the <code>cairo_pdf</code> function the output doesn't change.</p>
  
  <p>Could you please help me understand what do I have to do so the tittle + subtitle fit in the image? </p>
  
  <p><a href="https://i.stack.imgur.com/hK3lj.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/hK3lj.png" alt="enter image description here"></a></p>