title: Clipping a las file with a shapefile getting error
body: <p>I want to clip a las file with 5m radius shapefile.</p>
  <pre class="lang-r prettyprint-override"><code>library(rgdal)
  library(lidR)
  library(sp)
  library(raster)
  ctg = readLAS(&quot;............&quot;)
  plot(ctg)
  
  spdf &lt;- readOGR(dsn = &quot;.......&quot;, layer = &quot;shapefile&quot;)
  plot(spdf)
  
  clipped_las = clip_roi(ctg, spdf)
  plot(clipped_las)
  </code></pre>
  <p>But I am getting following error:</p>
  <pre class="lang-r prettyprint-override"><code>clipped_las = clip_roi(ctg, spdf)
  #&gt; Error in st_geos_binop(&quot;intersects&quot;, x, y, sparse = sparse, prepared = prepared,  : 
  #&gt;  st_crs(x) == st_crs(y) is not TRUE
  
  plot(clipped_las)
  #&gt; Error: Cannot display an empty point cloud
  </code></pre>
  <p>Alternatively I tried:</p>
  <pre class="lang-r prettyprint-override"><code>ctg = readLAScatalog(&quot;.......&quot;)
  plot(ctg)
  
  spdf &lt;- readOGR(dsn = &quot;.......&quot;, layer = &quot;shapefile&quot;)
  plot(spdf)
  
  poly &lt;- spdf@polygons[[1]]@Polygons[[1]]
  clipped_las = clip_roi(ctg, poly)
  
  plot(clipped_las)
  </code></pre>
  <p>In that case I am getting following error:</p>
  <pre class="lang-r prettyprint-override"><code>clipped_las = clip_roi(ctg, poly)
  #&gt; Processing [=======================================================] 100% (1/1) eta:  0s
  #&gt; No point found for within region of interest 1.
  </code></pre>
  <p>How can I clip the pointcloud?</p>