title: Error regarding use of the function "geom_hdr_rug" on Mac vs PC
body: <p>The code below works fine on my Mac but it will not run on my PC, as I continue to get the error message below the code. Any suggestions? Thanks!!</p>
  <pre><code>ggplot(data=sp, aes(x=elevm, y=dist)) +
  geom_point(aes(x=elevm, y=dist)) +
  theme(legend.position=&quot;top&quot;) +
  geom_hdr_rug(aes(x = elevm), na.rm=TRUE, prob = c(0.99, 0.50, 0.25), fill = &quot;blue&quot;)+
  geom_point(na.rm=TRUE, aes(colour = hdr_bin(x=elevm, y=dist))) +
  scale_colour_viridis_d(direction = -1)
  </code></pre>
  <p>Error in alpha(fill_shade, data$alpha) :
  Data must either be a data frame or a matrix</p>