title: How do I use the same output for multiple diagrams?
body: <p>I also posted the following as a <a href="https://github.com/diagrams/diagrams-doc/issues/112" rel="nofollow noreferrer"><code>diagrams-doc</code> issue</a>, but I thought it might be more appropriate here.</p>
  
  <p>The user manual <a href="http://projects.haskell.org/diagrams/doc/manual.html#output-units" rel="nofollow noreferrer">says this</a>: </p>
  
  <blockquote>
    <p>One situation in which output units can be particularly useful is when preparing a document (paper, blog post, etc.) with multiple embedded diagrams of various physical sizes. Using the same output value for the line width (or arrowhead length, arrow gap, font size, etc.) of every diagram ensures that the diagrams will all look consistent.</p>
  </blockquote>
  
  <p>This is exactly what I'd like to do.  I am making a webpage with multiple <code>diagrams</code>-generated svg files of different sizes inline, and I'd like the line widths, arrowhead sizes, and circle radii to be consistent.  But I'm not sure how.  How would I pass the same output value to all the arrows, arrowheads, circles, etc.?  And when I ultimately render with <code>renderPretty</code>, what would I set <code>size</code> to in the <code>SVGOptions</code> argument so that it just makes the svg whatever size its contents are?</p>