pdf method

@override double pdf(double x)

Probability Density Function (PDF).

Implementation

@override
double pdf(double x) {
  if (x.isNaN) {
    throw ArgumentError.value(x);
  }
  if (x == double.negativeInfinity) {
    return 0.0;
  }
  if (x == double.infinity) {
    return 1.0;
  }
  final mean = this.mean;
  final variance = this.variance;
  if (variance == 0.0) {
    return x < mean ? 0.0 : 1.0;
  }
  final t = (x - mean) / variance;
  return (1 / (variance * sqrt(2 * pi))) * pow(e, -0.5 * t * t);
}