grossvogel

Verifying that +jasonpollentier is my openname (Bitcoin username). https://onename.io/jasonpollentier

grossvogel

Keybase proof

I hereby claim:

• I am grossvogel on github.
• I am grossvogel (https://keybase.io/grossvogel) on keybase.
• I have a public key ASDhRR3NZWThtuOPAPEE8vxip4a_OV2JIWLAbtxWgLf4CAo

To claim this, I am signing this object:

grossvogel

describe('addition', () => {
  describe('is commutative', () => {
    it('gives the same result when adding numbers in either order', () => {
      // presumably both equal 3, but that could be tested elsewhere
      assert.equal(add(1, 2), add(2, 1));
    });
  });
});

grossvogel

const jsc = require('jsverify');

describe('addition', () => {
  it('is commutative'() => {
    const commutativeTest = (a, b) => add(a, b) === add(b, a);
    const commutativeProperty = jsc.forall(jsc.number, jsc.number, commutativeTest);

    jsc.assert(commutativeProperty);
  });
});

grossvogel

class Polynomial {
  /**
   * @param {array} coefficients
   *   with coefficients[i] being the coefficient for X^i
   */
  constructor(coefficients) {
    // remove leading 0s, so 0x^2 + 2x + 1 becomes 2x + 1
    this._coefficients = this._trimCoefficients(coefficients);
  }

grossvogel

class Polynomial {
  //...
  get derivative() {
    const newCoefficients = this.coefficients
      .map((coefficient, degree) => coefficient * degree)
      .slice(1);
    return new Polynomial(newCoefficients);
  }
  //...
}

grossvogel

/**
 * Find a zero of the given polynomial near the provided guess
 * @param {Polynomial} polynomial
 * @param {number} guessX - x value near the zero we're looking for
 * @param {number} tolerance - how close we need to be to the desired Y
 * @param {number} maxIterations - how many iterations before we fail
 */
const solve = (polynomial, guessX, tolerance = 0.000001, maxIterations = 1000) => {
  const derivative = polynomial.derivative;
  let iteration = 0;

grossvogel

/**
 * Size in the case of polynomials will be the length of the coefficients array,
 * which is one more than the degree of the polynomial
 * For simplicity, use integer coefficients
 * @param {Integer} size
 */
const generator = size => {
  const coefficients = [];
  for (i = 0; i < size; i++) {
    coefficients.push(jsc.random(-MAX_COEFFICIENT, MAX_COEFFICIENT));

grossvogel

... snip: a bunch of passing inputs
[ 13, 10, 38, 33, 19 ]
[ 10, 38, 33, 19 ]
[ 6, 10, 38, 33, 19 ]
[ 9, 10, 38, 33, 19 ]
[ 10, 10, 38, 33, 19 ]
[ 10, 38, 33, 19 ]
[ 5, 10, 38, 33, 19 ]
[ 7, 10, 38, 33, 19 ]
[ 8, 10, 38, 33, 19 ]

grossvogel

const boundedInt = jsc.integer(-MAX_COEFFICIENT, MAX_COEFFICIENT);
const polynomialArbitrary = jsc.nearray(boundedInt).smap(
  Polynomial.create,
  Polynomial.getCoefficents
);