/// <summary>
/// This function calculate the status value for an incomplete equation.
/// This should be called if the IsCompleteEquation() method returns false.
/// </summary>
/// <returns>An enum value of type 'LinearEquationParserStatus'</returns>
private LinearEquationParserStatus GetEquationStatus()
{
LinearEquationParserStatus status = LinearEquationParserStatus.Success;
if ((!m_equalSignInEquationFlag) &&
(!m_termBeforeEqualSignExistsFlag) &&
(!m_termAfterEqualSignExistsFlag) &&
(!m_atLeastOneVariableInEquationFlag))
{
status = LinearEquationParserStatus.SuccessNoEquation;
}
else if (!m_equalSignInEquationFlag)
{
status = LinearEquationParserStatus.ErrorNoEqualSign;
}
else if (!m_termBeforeEqualSignExistsFlag)
{
status = LinearEquationParserStatus.ErrorNoTermBeforeEqualSign;
}
else if (!m_termAfterEqualSignExistsFlag)
{
status = LinearEquationParserStatus.ErrorNoTermAfterEqualSign;
}
else if (!m_atLeastOneVariableInEquationFlag)
{
status = LinearEquationParserStatus.ErrorNoVariableInEquation;
}
else
{
status = LinearEquationParserStatus.Success;
}
return(status);
}
private void Solve()
{
mainToolStripStatusLabel.Text = Properties.Resources.IDS_SOLVING_EQUATIONS;
Sparse2DMatrix <int, int, double> aMatrix = new Sparse2DMatrix <int, int, double>();
SparseArray <int, double> bVector = new SparseArray <int, double>();
SparseArray <string, int> variableNameIndexMap = new SparseArray <string, int>();
int numberOfEquations = 0;
LinearEquationParser parser = new LinearEquationParser();
LinearEquationParserStatus parserStatus = LinearEquationParserStatus.Success;
foreach (string inputLine in equationsRichTextBox.Lines)
{
parserStatus = parser.Parse(inputLine,
aMatrix,
bVector,
variableNameIndexMap,
ref numberOfEquations);
if (parserStatus != LinearEquationParserStatus.Success)
{
break;
}
}
// Assume success.
string mainStatusBarText = Properties.Resources.IDS_EQUATIONS_SOLVED;
// Did an error occur?
if (parserStatus == LinearEquationParserStatus.Success)
{
// Are there the same number of equations as variables?
if (numberOfEquations == variableNameIndexMap.Count)
{
// Create a solution vector.
SparseArray <int, double> xVector = new SparseArray <int, double>();
// Solve the simultaneous equations.
LinearEquationSolverStatus solverStatus =
LinearEquationSolver.Solve(numberOfEquations,
aMatrix,
bVector,
xVector);
if (solverStatus == LinearEquationSolverStatus.Success)
{
string solutionString = "";
foreach (KeyValuePair <string, int> pair in variableNameIndexMap)
{
solutionString += string.Format("{0} = {1}", pair.Key, xVector[pair.Value]);
solutionString += "\n";
}
equationsRichTextBox.Text += "\n" + solutionString;
}
else if (solverStatus == LinearEquationSolverStatus.IllConditioned)
{
mainStatusBarText = Properties.Resources.IDS_ILL_CONDITIONED_SYSTEM_OF_EQUATIONS;
}
else if (solverStatus == LinearEquationSolverStatus.Singular)
{
mainStatusBarText = Properties.Resources.IDS_SINGULAR_SYSTEM_OF_EQUATIONS;
}
}
else if (numberOfEquations < variableNameIndexMap.Count)
{
mainStatusBarText = string.Format(Properties.Resources.IDS_TOO_FEW_EQUATIONS,
numberOfEquations, variableNameIndexMap.Count);
}
else if (numberOfEquations > variableNameIndexMap.Count)
{
mainStatusBarText = string.Format(Properties.Resources.IDS_TOO_MANY_EQUATIONS,
numberOfEquations, variableNameIndexMap.Count);
}
}
else
{
// An error occurred. Report the error in the status bar.
mainStatusBarText = LinearEquationParserStatusInterpreter.GetStatusString(parserStatus);
}
mainToolStripStatusLabel.Text = mainStatusBarText;
}
public string SolveEquation(string equation)
{
Sparse2DMatrix <int, int, double> aMatrix = new Sparse2DMatrix <int, int, double>();
SparseArray <int, double> bVector = new SparseArray <int, double>();
SparseArray <string, int> variableNameIndexMap = new SparseArray <string, int>();
int numberOfEquations = 0;
LinearEquationParser parser = new LinearEquationParser();
LinearEquationParserStatus parserStatus = LinearEquationParserStatus.Success;
string[] lines = equation.Split(new[] { "\r\n", "\r", "\n", "\\n", "," }, StringSplitOptions.None);
foreach (string inputLine in lines)
{
parserStatus = parser.Parse(inputLine,
aMatrix,
bVector,
variableNameIndexMap,
ref numberOfEquations);
if (parserStatus != LinearEquationParserStatus.Success)
{
break;
}
}
// Assume success.
string mainStatusBarText = "Equations solved";
// Did an error occur?
if (parserStatus == LinearEquationParserStatus.Success)
{
// Are there the same number of equations as variables?
if (numberOfEquations == variableNameIndexMap.Count)
{
// Create a solution vector.
SparseArray <int, double> xVector = new SparseArray <int, double>();
// Solve the simultaneous equations.
LinearEquationSolverStatus solverStatus =
LinearEquationSolver.Solve(numberOfEquations,
aMatrix,
bVector,
xVector);
if (solverStatus == LinearEquationSolverStatus.Success)
{
string solutionString = "";
foreach (KeyValuePair <string, int> pair in variableNameIndexMap)
{
solutionString += string.Format("{0} = {1}" + " ", pair.Key, xVector[pair.Value]);
}
return(solutionString);
}
else if (solverStatus == LinearEquationSolverStatus.IllConditioned)
{
mainStatusBarText = "Error - the system of equations is ill conditioned.";
}
else if (solverStatus == LinearEquationSolverStatus.Singular)
{
mainStatusBarText = "Error - the system of equations is singular.";
}
}
else if (numberOfEquations < variableNameIndexMap.Count)
{
mainStatusBarText = string.Format("Only {0} equations is too few equations for {1} variables", numberOfEquations, variableNameIndexMap.Count);
}
else if (numberOfEquations > variableNameIndexMap.Count)
{
mainStatusBarText = string.Format("{0} equations is too many equations for only {1} variables", numberOfEquations, variableNameIndexMap.Count);
}
}
else
{
// An error occurred. Report the error in the status bar.
mainStatusBarText = LinearEquationParserStatusInterpreter.GetStatusString(parserStatus);
}
return(mainStatusBarText);
}
/// <summary>
/// This method returns a status string corresponding to the passed
/// status value returned from the LinearEquationParser.Parse method.
/// </summary>
/// <param name="status">An status value of type LinearEquationParserStatus</param>
/// <returns>The string corresponding to the passed status code.</returns>
public static string GetStatusString(LinearEquationParserStatus status)
{
string statusString = "";
switch (status)
{
case LinearEquationParserStatus.Success:
case LinearEquationParserStatus.SuccessNoEquation:
statusString = Properties.Resources.IDS_SUCCESS;
break;
case LinearEquationParserStatus.ErrorIllegalEquation:
statusString = Properties.Resources.IDS_ERROR_ILLEGAL_EQUATION;
break;
case LinearEquationParserStatus.ErrorNoEqualSign:
statusString = Properties.Resources.IDS_ERROR_NO_EQUAL_SIGN;
break;
case LinearEquationParserStatus.ErrorMultipleEqualSigns:
statusString = Properties.Resources.IDS_ERROR_MULTIPLE_EQUAL_SIGNS;
break;
case LinearEquationParserStatus.ErrorNoTermBeforeEqualSign:
statusString = Properties.Resources.IDS_ERROR_NO_TERM_BEFORE_EQUAL_SIGN;
break;
case LinearEquationParserStatus.ErrorNoTermAfterEqualSign:
statusString = Properties.Resources.IDS_ERROR_NO_TERM_AFTER_EQUAL_SIGN;
break;
case LinearEquationParserStatus.ErrorNoTermEncountered:
statusString = Properties.Resources.IDS_ERROR_NO_TERM_ENCOUNTERED;
break;
case LinearEquationParserStatus.ErrorNoVariableInEquation:
statusString = Properties.Resources.IDS_ERROR_NO_VARIABLE_IN_EQUATION;
break;
case LinearEquationParserStatus.ErrorMultipleDecimalPoints:
statusString = Properties.Resources.IDS_ERROR_MULTIPLE_DECIMAL_POINTS;
break;
case LinearEquationParserStatus.ErrorTooManyDigits:
statusString = Properties.Resources.IDS_ERROR_TOO_MANY_DIGITS;
break;
case LinearEquationParserStatus.ErrorMissingExponent:
statusString = Properties.Resources.IDS_ERROR_MISSING_EXPONENT;
break;
case LinearEquationParserStatus.ErrorIllegalExponent:
statusString = Properties.Resources.IDS_ERROR_ILLEGAL_EXPONENT;
break;
default:
statusString = Properties.Resources.IDS_ERROR_ILLEGAL_EQUATION;
break;
}
return(statusString);
}
private void SetLastStatusValue(LinearEquationParserStatus status,
int positionIndex)
{
LastStatusValue = status;
ErrorPosition = positionIndex;
}
public static string GetStatusString(LinearEquationParserStatus status)
{
string statusString = "";
switch (status)
{
case LinearEquationParserStatus.Success:
case LinearEquationParserStatus.SuccessNoEquation:
statusString = "The equation was parsed successfully.";
break;
case LinearEquationParserStatus.ErrorIllegalEquation:
statusString = "The equation syntax is illegal.";
break;
case LinearEquationParserStatus.ErrorNoEqualSign:
statusString = "There is no equal sign in the equation.";
break;
case LinearEquationParserStatus.ErrorMultipleEqualSigns:
statusString = "There are multiple equal signs in the equation.";
break;
case LinearEquationParserStatus.ErrorNoTermBeforeEqualSign:
statusString = "There is no term before the equal sign in the equation.";
break;
case LinearEquationParserStatus.ErrorNoTermAfterEqualSign:
statusString = "There is no term after the equal sign in the equation.";
break;
case LinearEquationParserStatus.ErrorNoTermEncountered:
statusString = "A number or a variable was expected.";
break;
case LinearEquationParserStatus.ErrorNoVariableInEquation:
statusString = "There is no variable in the equation.";
break;
case LinearEquationParserStatus.ErrorMultipleDecimalPoints:
statusString = "A number contains more than one decimal point.";
break;
case LinearEquationParserStatus.ErrorTooManyDigits:
statusString = "A number contains more than 15 digits.";
break;
case LinearEquationParserStatus.ErrorMissingExponent:
statusString = "A number contains the '^' character and is missing an exponent.";
break;
case LinearEquationParserStatus.ErrorIllegalExponent:
statusString = "A number contains an illegal exponent.";
break;
default:
statusString = "The equation syntax is illegal.";
break;
}
return(statusString);
}
