title: How to find maximum of a function with condition?
body: <p>I need to solve two equations with four variables. The constants are (c1-5) and the  four variables are (a,b,c,d). I need to maximize S. It does not matter if its exact or some kind of simulation.</p>
  <p>S = a^c1 * b^c2 * c^c3 * d^c4</p>
  <p>a + b + c + d = c5</p>
  <p>I could of course optimize with a grid search but I was just wondering if there is a package that makes it easy to solve such equation?</p>
  <p>I tried to do a Google search, but I have not found anything useful so far.</p>