fix: hadnle zeros at the endpoints in BisectionMethod (#1640)

* fix: hadnle zeros at the endpoints

* style: use simpler syntax express polynomials

Co-authored-by: appgurueu <34514239+appgurueu@users.noreply.github.com>

---------

Co-authored-by: appgurueu <34514239+appgurueu@users.noreply.github.com>
This commit is contained in:
Piotr Idzik
2024-04-03 17:18:45 +02:00
committed by GitHub
parent 702840b4c8
commit 34a663aca7
2 changed files with 14 additions and 13 deletions

View File

@ -1,14 +1,7 @@
import { findRoot } from '../BisectionMethod'
test('Equation f(x) = x^2 - 3*x + 2 = 0, has root x = 1 in [a, b] = [0, 1.5]', () => {
const root = findRoot(
0,
1.5,
(x) => {
return Math.pow(x, 2) - 3 * x + 2
},
8
)
const root = findRoot(0, 1.5, (x) => x ** 2 - 3 * x + 2, 8)
expect(root).toBe(0.9990234375)
})
@ -35,3 +28,12 @@ test('Equation f(x) = sqrt(x) + e^(2*x) - 8*x = 0, has root x = 0.93945851 in [a
)
expect(Number(Number(root).toPrecision(8))).toBe(0.93945851)
})
test('Equation f(x) = x^3 = 0, has root x = 0.0 in [a, b] = [-1.0, 1.0]', () => {
const root = findRoot(-1.0, 1.0, (x) => x ** 3, 32)
expect(root).toBeCloseTo(0.0, 5)
})
test('Throws an error when function does not change sign', () => {
expect(() => findRoot(-1.0, 1.0, (x) => x ** 2, 10)).toThrowError()
})