RevitLookup.Test.SDKSamples.StructuralSample.StructSample.ACos C# (CSharp) Method

        private double ACos( double d )
        {
            //  we probably need to consider tolerance here.
              if( Math.Abs( d ) != 1.0 )
              {
            return ( 1.5707963267949 - Math.Atan( d / Math.Sqrt( 1.0 - d * d ) ) );
              }
              if( d == -1.0 )
              {
            return 3.14159265358979;
              }
              return 0.0;
        }