docs: protected void computeRotator( double rise , double run )
      {
  //        double gamma = Math.sqrt(rise*rise + run*run);
  //
  //        c = rise/gamma;
  //        s = run/gamma;
  
          // See page 384 of Fundamentals of Matrix Computations 2nd
            if( Math.abs(rise) < Math.abs(run)) {
                double k = rise/run;
  
                double bottom = Math.sqrt(1.0+k*k);
                s = 1.0/bottom;
                c = k/bottom;
            } else {
                double t = run/rise;
                double bottom = Math.sqrt(1.0 + t*t);
                c = 1.0/bottom;
                s = t/bottom;
            }
      }