title: What's the easiest way to do vector/matrix math in iOS?
body: <p>I want to do some simple linear algebra in an iOS app.  I need to multiply a couple 4x4 matrices, and then multiply it with a vec4.</p>
  <p>I see there is <code>CATransform3D</code> which appears to implement some basic matrix multiplication features, but I can't seem to find anything about vector multiplications in core animation.</p>
  <p>Is there a way to accomplish this with <code>CATransform3D</code>, or else is there another Linear Algebra library that comes as part of the iOS SDK?</p>