title: Unit testing with floating point values
body: <p>I have created a class <code>Matrix</code> to do mathematical operation on floating point matrices (basic operations, inverse, ...).</p>
  
  <p>Floating point precision make it difficult to test them.
  Typically, if test the inverse operation, the error can be huge if the determinant of the matrix is close to zero.</p>
  
  <p>How can I do unit testing on these operations?</p>