public void PartialDerivativeTest1()
{
// lg(2xy)
IExpression exp = new Lg(new Mul(new Mul(new Number(2), new Variable("x")), new Variable("y")));
IExpression deriv = exp.Differentiate();
Assert.AreEqual("((2 * 1) * y) / (((2 * x) * y) * ln(10))", deriv.ToString());
}
public void PartialDerivativeTest2()
{
// lg(2xy)
IExpression exp = new Lg(new Variable("x"));
IExpression deriv = exp.Differentiate(new Variable("y"));
Assert.AreEqual("0", deriv.ToString());
}
public void DerivativeTest2()
{
// lg(2x)
Number num = new Number(2);
Variable x = new Variable("x");
Mul mul = new Mul(num, x);
IExpression exp = new Lg(mul);
IExpression deriv = exp.Differentiate();
Assert.AreEqual("(2 * 1) / ((2 * x) * ln(10))", deriv.ToString());
num.Value = 3;
Assert.AreEqual("lg(3 * x)", exp.ToString());
Assert.AreEqual("(2 * 1) / ((2 * x) * ln(10))", deriv.ToString());
}