import 'package:flutter/gestures.dart'; import 'package:test/test.dart'; void main() { approx(double value, double expectation) { const double eps = 1e-6; return (value - expectation).abs() < eps; } test('Least-squares fit: linear polynomial to line', () { List<double> x = <double>[0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0]; List<double> y = <double>[1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0]; List<double> w = <double>[1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0]; LeastSquaresSolver solver = new LeastSquaresSolver(x, y, w); PolynomialFit fit = solver.solve(1); expect(fit.coefficients.length, 2); expect(approx(fit.coefficients[0], 1.0), isTrue); expect(approx(fit.coefficients[1], 0.0), isTrue); expect(approx(fit.confidence, 1.0), isTrue); }); test('Least-squares fit: linear polynomial to sloped line', () { List<double> x = <double>[0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0]; List<double> y = <double>[1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0]; List<double> w = <double>[1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0]; LeastSquaresSolver solver = new LeastSquaresSolver(x, y, w); PolynomialFit fit = solver.solve(1); expect(fit.coefficients.length, 2); expect(approx(fit.coefficients[0], 1.0), isTrue); expect(approx(fit.coefficients[1], 1.0), isTrue); expect(approx(fit.confidence, 1.0), isTrue); }); test('Least-squares fit: quadratic polynomial to line', () { List<double> x = <double>[0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0]; List<double> y = <double>[1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0]; List<double> w = <double>[1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0]; LeastSquaresSolver solver = new LeastSquaresSolver(x, y, w); PolynomialFit fit = solver.solve(2); expect(fit.coefficients.length, 3); expect(approx(fit.coefficients[0], 1.0), isTrue); expect(approx(fit.coefficients[1], 0.0), isTrue); expect(approx(fit.coefficients[2], 0.0), isTrue); expect(approx(fit.confidence, 1.0), isTrue); }); test('Least-squares fit: quadratic polynomial to sloped line', () { List<double> x = <double>[0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0]; List<double> y = <double>[1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0]; List<double> w = <double>[1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0]; LeastSquaresSolver solver = new LeastSquaresSolver(x, y, w); PolynomialFit fit = solver.solve(2); expect(fit.coefficients.length, 3); expect(approx(fit.coefficients[0], 1.0), isTrue); expect(approx(fit.coefficients[1], 1.0), isTrue); expect(approx(fit.coefficients[2], 0.0), isTrue); expect(approx(fit.confidence, 1.0), isTrue); }); }