/// <summary>
/// Represents copy of variable
/// </summary>
/// <exception cref="NullReferenceException"></exception>
public Variable(Variable variable)
{
_coefficient = new Fraction(variable._coefficient);
SetLabel(variable.Label);
Power = variable.Power;
}
/// <summary>
/// Adds var to current variable
/// </summary>
/// <exception cref="NullReferenceException"></exception>
public void Add(Variable var)
{
if (var.Label != Label || var.Power != Power)
throw new FormatException("Input variable must be with same labels and powers");
_coefficient += var._coefficient;
}
/// <summary>
/// Multiplys Constraint(left and right sides) by number
/// </summary>
public void Multiply(int number)
{
for (var i = 0; i < _leftSide.Count; i++)
{
_leftSide[i] = new Variable(_leftSide[i]);
_leftSide[i].Multiply(number);
}
if (number < 0)
ChangeSign();
_rightSide *= number;
}
/// <summary>
/// Multiplys Constraint(left and right sides) by fraction
/// </summary>
/// <exception cref="NullReferenceException"></exception>
public void Multiply(Fraction fraction)
{
for (var i = 0; i < _leftSide.Count; i++)
{
_leftSide[i] = new Variable(_leftSide[i]);
_leftSide[i].Multiply(fraction);
}
//foreach (Variable var in this._leftSide)
// var.Multiply(fraction);
if (fraction < 0)
ChangeSign();
_rightSide *= fraction;
}
/// <summary>
/// Divides Constraint(left and right sides) by number
/// </summary>
/// <exception cref="DivideByZeroException"></exception>
public void Divide(int number)
{
for (var i = 0; i < _leftSide.Count; i++)
{
_leftSide[i] = new Variable(_leftSide[i]);
_leftSide[i].Divide(number);
}
//foreach (Variable var in this._leftSide)
// var.Divide(number);
if (number < 0)
ChangeSign();
_rightSide /= number;
}
/// <summary>
/// Adds variable with or without sign change
/// </summary>
/// <param name="var">Variable</param>
/// <param name="withSignChange">If true change sign('>=' -> '=', if var.Coefficient less than 0)</param>
public void AddVariable(Variable var, bool withSignChange)
{
if (withSignChange)
{
if (var.Coefficient > 0)
Sign = Sign == "<=" || Sign == "<" ? "=" : Sign;
if (var.Coefficient < 0)
Sign = Sign == ">=" || Sign == ">" ? "=" : Sign;
}
for (var i = 0; i < _leftSide.Count; i++)
if (_leftSide[i].Label == var.Label && _leftSide[i].Power == var.Power)
{
var tmp = _leftSide[i];
_leftSide.Remove(tmp);
var newVar = new Variable(var.Coefficient + tmp.Coefficient, var.Label, var.Power);
_leftSide.Add(newVar);
return;
}
_leftSide.Add(new Variable(var));
}
/// <summary>
/// Removes variable from target function by label
/// </summary>
public void RemoveVariable(string variableLabel)
{
var removedVariable = new Variable();
foreach (var variable in _formula)
if (variable.Label == variableLabel)
{
removedVariable = variable;
break;
}
_formula.Remove(removedVariable);
_arguments.Remove(variableLabel);
if (_variablesWithMaxCoefficient.Contains(variableLabel))
_variablesWithMaxCoefficient.Remove(variableLabel);
}
/// <summary>
/// Adds variable to formula
/// </summary>
/// <exception cref="NullReferenceException"></exception>
public void AddVariable(Variable var)
{
if (_arguments.Contains(var.Label))
{
for (var i = 0; i < _formula.Count; i++)
if (_formula[i].Label == var.Label && _formula[i].Power == var.Power)
{
var tmp = _formula[i];
_formula.Remove(tmp);
var newVar = new Variable(var.Coefficient + tmp.Coefficient, var.Label, var.Power);
_formula.Add(newVar);
return;
}
}
_formula.Add(new Variable(var.Coefficient, var.Label, var.Power));
_arguments.Add(var.Label);
}
/// <summary>
/// Adds zero constrain for specified variable
/// </summary>
private void AddZeroConstraint(string variableLabel)
{
var variable = new Variable("1/1", variableLabel);
ZeroConstraints.Add(new Constraint(new List<Variable> { variable }, ">=", "0/0"));
}
