magnitudeVenus function

double magnitudeVenus(
  1. double r,
  2. double delta,
  3. double i
)

Visual magnitude of Venus. i is phase angle in radians.

Implementation

double magnitudeVenus(double r, double delta, double i) {
  final id = toDeg(i);
  return -4 + 5 * math.log(r * delta) / math.ln10 + (0.01322 + 0.0000004247 * id * id) * id;
}