public override Operand Simplify()
{
Sine simplifiedExpression = new Sine();
simplifiedExpression.LeftSuccessor = LeftSuccessor.Simplify();
return(simplifiedExpression);
}
public override Operand Copy()
{
Sine copy = new Sine();
copy.LeftSuccessor = LeftSuccessor.Copy();
return(copy);
}
public override Operand Differentiate()
{
// Apply the chain rule.
// Derivative of cos(u) = -sin(u) * u'
Sine rightOuterDerivativeExpression = new Sine();
// s(u)
rightOuterDerivativeExpression.LeftSuccessor = LeftSuccessor.Copy();
// -1 * sin(u)
Multiplication outerDerivative = new Multiplication();
outerDerivative.LeftSuccessor = new Integer(-1);
outerDerivative.RightSuccessor = rightOuterDerivativeExpression;
// Now for u' we call it's differentiate method.
Operand innerDerivative = LeftSuccessor.Differentiate();
Multiplication derivative = new Multiplication();
derivative.LeftSuccessor = outerDerivative;
derivative.RightSuccessor = innerDerivative;
return(derivative);
}
// Method that will create an appropriate operator class
// from the obtained character.
private void CreateNode(char operat0r)
{
Operand result = null;
switch (operat0r)
{
case '+':
result = new Addition();
break;
case '-':
result = new Subtraction();
break;
case '*':
result = new Multiplication();
break;
case '/':
result = new Division();
break;
case '^':
result = new Power();
break;
// Now for operators that take one argument.
case '!':
result = new Factorial();
break;
case 'l':
result = new NaturalLog();
break;
case 'e':
result = new Exp();
break;
case 'c':
result = new Cosine();
break;
case 's':
result = new Sine();
break;
}
if (result is BinaryOperator)
{
// Add the operands to the binary operator.
((BinaryOperator)result).LeftSuccessor = operands[operands.Count - 2];
((BinaryOperator)result).RightSuccessor = operands[operands.Count - 1];
// Remove the operands from the stack.
operands.RemoveAt(operands.Count - 1);
operands.RemoveAt(operands.Count - 1);
}
else
{
// Same story, add operand to unary operator.
((UnaryOperator)result).LeftSuccessor = operands[operands.Count - 1];
// Remove operand from stack.
operands.RemoveAt(operands.Count - 1);
}
// Add the sub tree on top of the operands stack.
operands.Add(result);
}