title: Function to translate linear equations into matrix form in R?
body: <p>I was wondering whether there exist any packages or other pre-built solutions for R that are capable of translating sets of linear equations into matrix form (e.g. for solution via the <a href="https://en.wikipedia.org/wiki/Gauss%E2%80%93Seidel_method" rel="noreferrer">Gauss Seidel algorithm</a>), similar to the <code>equationsToMatrix(eqns,vars)</code> <a href="http://www.mathworks.com/help/symbolic/equationstomatrix.html?lang=en" rel="noreferrer">function in Matlab</a>?</p>
  
  <p>An example from Matlab:</p>
  
  <pre><code>[A, b] = equationsToMatrix([x - y == 0, x + 2*y == 3, [x, y])
  
  A =
  [ 1, -1]
  [ 1, 2]
  
  b =
    0
    3
  </code></pre>
  
  <p>Suggestions for building blocks would be very helpful, too.</p>