code: private double getDeclination( double dayangb ) {
          double delta = .3723 + 23.2567 * Math.sin(dayangb) - .758 * Math.cos(dayangb) + .1149 * Math.sin(2 * dayangb) + .3656
                  * Math.cos(2 * dayangb) - .1712 * Math.sin(3 * dayangb) + .0201 * Math.cos(3 * dayangb);
          return Math.toRadians(delta);
      }
docs: /*
  Evaluate the declination.