public MathFunction(string inputExpression)
{
// Name
inputExpression = inputExpression.Replace(" ", string.Empty);
Name = Regex.Match(inputExpression, @"^([^()]*)\(").Groups[1].Value;
// Variables
Variables = GetVariablesList(inputExpression);
// Formula
string rawFormula = Regex.Match(inputExpression, @"(?<==).*$").Value;
List <string> infixFormula = ExpressionManaging.ExpressionToInfix(rawFormula);
Formula = ExpressionManaging.InfixToPostfix(infixFormula);
}
static void Main(string[] args)
{
// to change language of exceptions' messages ;)
Thread.CurrentThread.CurrentUICulture = new CultureInfo("en-us");
//
List <MathFunction> Functions = new List <MathFunction>();
for (;;)
{
try
{
Console.WriteLine();
Console.WriteLine("Type specific letter to perform action:");
Console.WriteLine("f - to define new function");
Console.WriteLine("c - to give arguments to calculate existing function");
Console.WriteLine("x - to calculate direct given expression");
Console.WriteLine("h - to get help");
Console.WriteLine("q - to quit");
string userChoice = Console.ReadLine();
if (userChoice.Equals("q"))
{
Console.WriteLine("Bye bye!");
break;
}
else if (userChoice.Equals("f"))
{
Console.WriteLine("Provide function's pattern below:");
string inputExpression = Console.ReadLine();
if (inputExpression.Equals("") || !inputExpression.Contains("="))
{
Console.WriteLine("Given funtion is incomplete.");
continue;
}
string functionName = Regex.Match(inputExpression, @"^([^()]*)\(").Groups[1].Value;
MathFunction functionToRemove = Functions.SingleOrDefault(f => f.Name.Equals(functionName));
if (functionToRemove != null)
{
Console.WriteLine("Function with specified name already existed. Do you want to replace it with your function? y/n");
string choice = Console.ReadLine();
if (choice.Equals("y"))
{
Functions.Remove(functionToRemove);
}
else if (choice.Equals("n"))
{
continue;
}
else
{
Console.WriteLine("Unknown command, function not created.");
continue;
}
}
Functions.Add(new MathFunction(inputExpression));
}
else if (userChoice.Equals("c"))
{
Console.WriteLine("Provide function's symbol with variables' values below:");
string inputExpression = Console.ReadLine();
string functionName = Regex.Match(inputExpression, @"^([^()]*)\(").Groups[1].Value;
MathFunction functionToCompute = Functions.SingleOrDefault(f => f.Name.Equals(functionName));
if (functionToCompute != null)
{
inputExpression = inputExpression.Replace(" ", string.Empty);
string variablesSection = Regex.Match(inputExpression, @"\(([^()]*)\)").Groups[1].Value;
List <double> variablesValues = new List <double>();
string tempVariable = "";
foreach (string v in variablesSection.Select(c => c.ToString()).ToList())
{
if (v.Equals(","))
{
if (!tempVariable.Equals(""))
{
variablesValues.Add(Convert.ToDouble(tempVariable));
tempVariable = "";
}
else
{
continue;
}
}
else
{
tempVariable += v;
}
}
if (!tempVariable.Equals(""))
{
variablesValues.Add(Convert.ToDouble(tempVariable));
}
double result = functionToCompute.ComputeFunction(variablesValues);
Console.WriteLine(result.ToString());
}
else
{
Console.WriteLine("This function is not defined.");
}
}
else if (userChoice.Equals("x"))
{
Console.WriteLine("Provide expression to calculate:");
string inputExpression = Console.ReadLine();
List <string> postfixExpression = ExpressionManaging.InfixToPostfix(ExpressionManaging.ExpressionToInfix(inputExpression));
Console.WriteLine(Calculator.PerformCalculation(postfixExpression).ToString());
}
else if (userChoice.Equals("h"))
{
Console.WriteLine("*****************************************************************");
Console.WriteLine("Functions should be declared as below:");
Console.WriteLine("f(x,y,z) = x^3 + 2*x*y - 3*(y/z)^2 + z^2");
Console.WriteLine("Direct expressions should be given like this:");
Console.WriteLine("4.25 * (5.68/(2.1+3.44) - 89.2)^4.2");
Console.WriteLine("Spaces are non-compulsory - you can use them wherever you want.");
Console.WriteLine("*****************************************************************");
Console.WriteLine();
}
else
{
Console.WriteLine("Incorrect choice, try again.");
}
}
catch (Exception e)
{
Console.WriteLine("Exception has been caught:");
Console.WriteLine(e.Message);
}
}
}
public static double PerformCalculation(List <string> postfixExpression)
{
Heap <double> calcHeap = new Heap <double>();
try
{
foreach (string elem in postfixExpression)
{
if (ExpressionManaging.IsMathOperator(elem))
{
double secondOperand = calcHeap.Pop();
double firstOperand = calcHeap.Pop();
double result;
switch (elem)
{
case "+":
result = firstOperand + secondOperand;
break;
case "-":
result = firstOperand - secondOperand;
break;
case "*":
result = firstOperand * secondOperand;
break;
case "/":
result = firstOperand / secondOperand;
break;
case "^":
result = Math.Pow(firstOperand, secondOperand);
break;
default:
throw new ArgumentException("Wrong operator readed");
}
calcHeap.Push(result);
}
else
{
calcHeap.Push(Convert.ToDouble(elem));
}
}
}
catch (ArgumentException e)
{
Console.WriteLine(e.Message);
throw;
}
try
{
if (calcHeap.Amount != 1)
{
throw new ApplicationException("Wrong output data in method!");
}
else
{
return(calcHeap.Pop());
}
}
catch
{
throw;
}
}
