title: Matlab: 3d bar plot over specified axes
body: <p>Hallo SOers:
    After searching for a while, the answer still does show up for my question: <br>
  I have a data file like:</p>
  
  <pre><code>x  y     z
  10 100   30
  10 500   90
  10 600   200
  30 200   30
  90 120   300
  90 130   30
  90 200   60
  </code></pre>
  
  <p>In matlab, I want to plot z over (x, y), which are not continuous points. The plot point should be a bar.
  But plot3() seems do not support 3d bar plot,
  <br> and bar3() seems do not allow me to specify my (x,y) column.</p>
  
  <p>So how to get such sparse bar plot?</p>
  
  <p>Many thanks!</p>