X-axis labels on top out of the plot area
<p>I'm plotting a correlation heatmap with x-axis on top by using <code>switch_axis_position</code>.
The x-axis labels are somewhat long, so I want it to be rotated by using <code>angle=90</code> and align them by using <code>hjust=0</code>.
But this makes the labels too far from the x-axis and even gets them out of the plot area.</p>

<pre><code>library(gtable)
library(cowplot)
library(grid)

heatmap&lt;-ggplot(data=meltedh, aes(x=variable, y=X, fill=value))+
  geom_tile(color="White")+
  ylab("")+xlab("")+
  scale_fill_gradient2(low="blue3", high="red3", mid="white", 
                      midpoint=0,limit=c(-1,1), space="Lab", breaks=c(-0.5,0,0.5),
                      name="Correlation Coefficient")+
  theme(legend.position="bottom", 
        axis.text.x=element_text(angle=90, hjust=0))
heatmap
ggdraw(switch_axis_position(heatmap,axis='x'))
</code></pre>

<p><a href="https://i.stack.imgur.com/vMydv.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/vMydv.png" alt="enter image description here"></a>
How can I make this pretty? Any help would be great. Thanks.</p>