title: Is there a function to add patterns to a ggplot pie chart whilst keeping colours?
body: <p>I'm looking to create a pie chart with the relative abundance of groups, however, groups are then split into sub groups e.g. Group 1 is split into group 1a, group 1b, group 1c and so one for group 2 ect. I have 30 groups with varying levels of subgroups within e.g. some groups have just 2 subgroups and some have 4.</p>
  <p>I would like to colour the slices of a pie for a group the same colour but the subgroups as different patterns. e.g. Group one would all have a base colour of red, but group 1a would be solid colour, group 1b would be red with stripes and group 1c would be red with dots.</p>
  <p>Just wondered if anyone could inform me of the best way get a pie chart with colours in addition to patterns. Any material I have found thus far is just for putting different patterns on as a fill rather than manipulating the colours e.g. ggpattern.</p>
  <p>Your help is much appreciated! Please find my code for my pie chart below.</p>
  <pre><code>bpwc&lt;- ggplot(data, aes(x=&quot;&quot;, y=rel_abund, fill=Order_group))+
    geom_bar(width = 1, stat = &quot;identity&quot;, color=&quot;black&quot;)
  
  piewc &lt;- bpwc + coord_polar(&quot;y&quot;, start=0)
  piewc +theme_void()+facet_wrap(depth~replicate)+scale_fill_manual(values =c(glasbey()))```
  
  
  
  
  
  </code></pre>