// Import package
import 'package:rk4/rk4.dart';
import 'package:flutter/material.dart';

 RK4(
    xInit: 0,
    yInit: 0,
    criticalValue: 1,
    k1: (x, y) => 1 - y,
  ).run().forEach((rr) {
    print("------ x: ${rr.x} y: ${rr.y}");
  });

  RK4
      .second(
        xInit: 0,
        yInit: -0.4,
        yDInit: -0.6,
        l1: (x, y, yd) => pow(e, 2 * x) * sin(x) - 2 * y + 2 * yd,
        criticalValue: 1,
      )
      .run()
      .forEach((rr) {
    print("------ x: ${rr.x} y: ${rr.y}");
  });