@Test
public void testHypotenuse() throws Exception {
Random random = new Random();
for (int i = 0; i < TRIES; i++) {
double x = random.nextDouble();
double y = random.nextDouble();
double h = Math.hypot(x, y);
BigDecimal decimalX = BigDecimal.valueOf(x);
BigDecimal decimalY = BigDecimal.valueOf(y);
assertEquals(BigMath.hypot(x, y, CONTEXT).doubleValue() / h, 1, DBL_TOLERANCE);
assertEquals(BigMath.hypot(decimalX, decimalY, CONTEXT).doubleValue() / h, 1, DBL_TOLERANCE);
}
}
@Test(timeOut = TRIES * CBRT_FACTOR)
public void testCubeRoot() throws Exception {
Random random = new Random();
for (int i = 0; i < TRIES; i++) {
// BigInteger version
BigInteger integer = getRandomBigInteger(random);
MathContext context = getContextFor(integer, 3);
BigDecimal nthRoot = BigMath.cbrt(integer, context);
assertEquals(nthRoot.pow(3, context).toBigInteger(), integer);
// BigDecimal version
BigDecimal decimal = getRandomBigDecimal(random, CONTEXT);
BigDecimal sqrRoot = BigMath.cbrt(decimal, CONTEXT);
assertEquals(
sqrRoot.pow(3).round(CONTEXT).stripTrailingZeros(), decimal.stripTrailingZeros());
}
}
@Test
public void testNthRoot() throws Exception {
Random random = new Random();
// because it is very time-consuming.
for (int i = 0; i < Math.sqrt(TRIES); i++) {
int n = 2 + random.nextInt(ROOT_BOUND - 2);
// BigInteger version
BigInteger integer = getRandomBigInteger(random);
MathContext context = getContextFor(integer, n);
BigDecimal nthRoot = BigMath.nthRoot(integer, n, context);
assertEquals(nthRoot.pow(n, context).toBigInteger(), integer);
// BigDecimal version
BigDecimal decimal = getRandomBigDecimal(random, CONTEXT);
nthRoot = BigMath.nthRoot(decimal, n, CONTEXT);
assertEquals(
nthRoot.pow(n, CONTEXT).round(CONTEXT).stripTrailingZeros(),
decimal.stripTrailingZeros());
}
}