Algebraic.from constructor

Algebraic.from(List<Complex> coefficients)

Returns an Algebraic instance according with the number of coefficients passed. In particular:

• if length is 1, a Constant object is returned;
• if length is 2, a Linear object is returned;
• if length is 3, a Quadratic object is returned;
• if length is 4, a Cubic object is returned;
• if length is 5, a Quartic object is returned;
• if length is 6 or higher, a Laguerre object is returned.

For example, if the length of coefficients were 3 it would mean that you're trying to solve a quadratic equation (because a quadratic has exactly 3 coefficients).

final linear = Algebraic.from(const [
  Complex(1, 3),
  Complex.i(),
]);

In the above example, linear is of type Linear because the given coefficients represent the (1 + 3i)x + i = 0 equation.

Use this method when the coefficients can be complex numbers. If there were only real numbers, use the Algebraic.fromReal(coefficients) method which is more convenient.

Implementation

factory Algebraic.from(List<Complex> coefficients) {
  // Reminder: 'Complex' is immutable so there's no risk of getting undesired
  // side effects if 'coefficients' is altered
  switch (coefficients.length) {
    case 1:
      return Constant(
        a: coefficients[0],
      );
    case 2:
      return Linear(
        a: coefficients[0],
        b: coefficients[1],
      );
    case 3:
      return Quadratic(
        a: coefficients[0],
        b: coefficients[1],
        c: coefficients[2],
      );
    case 4:
      return Cubic(
        a: coefficients[0],
        b: coefficients[1],
        c: coefficients[2],
        d: coefficients[3],
      );
    case 5:
      return Quartic(
        a: coefficients[0],
        b: coefficients[1],
        c: coefficients[2],
        d: coefficients[3],
        e: coefficients[4],
      );
    default:
      return Laguerre(
        coefficients: coefficients,
      );
  }
}