private Expression.Expression ConvertSubtraction(SubtractionNode node)
{
return(new Subtraction
{
Left = ConvertToExpression(node.Left),
Right = ConvertToExpression(node.Right)
});
}
public override ASTNode VisitBinaryOperatorExpression(EquationGrammarParser.BinaryOperatorExpressionContext context)
{
InfixExpressionNode node;
int type = context.op.Type;
switch (type)
{
case EquationGrammarLexer.CARET:
node = new PowerNode();
break;
case EquationGrammarLexer.PLUS:
node = new AdditionNode();
break;
case EquationGrammarLexer.MINUS:
node = new SubtractionNode();
break;
case EquationGrammarLexer.ASTERISK:
node = new MultiplicationNode();
break;
case EquationGrammarLexer.DIVISION:
node = new DivisionNode();
break;
default:
throw new NotSupportedException();
}
node.Left = (ExpressionNode)Visit(context.left);
node.Right = (ExpressionNode)Visit(context.right);
node.Line = context.start.Line;
node.Position = context.start.Column;
return(node);
}
private NonlinearEquationDescription CompileEquations(RootNode root)
{
List <RPNExpression> rpnEquations = new List <RPNExpression>();
List <Expression.Expression> equations = new List <Expression.Expression>();
foreach (var constant in root.constants)
{
Expression.Expression right = ExpressionSimplifier.Simplify(ConvertToExpression(constant.Right));
//ExpressionNode right = simplify(constant.Right);
if (right is Float)
{
constants.Add(constant.Identifier, ((Float)right).Value);
}
else
{
constants.Add(constant.Identifier, float.NaN);
compilerErrors.Add(new ErrorMessage("Определение константы " + constant.Identifier + " не является константным выражением"));
}
}
foreach (var equation in root.equations)
{
SubtractionNode subtraction = new SubtractionNode
{
Left = equation.Left,
Right = equation.Right,
Line = equation.Line,
Position = equation.Position
};
Expression.Expression expression = ExpressionSimplifier.Simplify(ConvertToExpression(subtraction));
equations.Add(expression);
}
//initialValues aren't important
foreach (var initialValue in root.initialValues)
{
if (variables.ContainsKey(initialValue.Identifier))
{
Expression.Expression right = ExpressionSimplifier.Simplify(ConvertToExpression(initialValue.Right));
//Expression expression = ConvertToExpression(right)
if (right is Float)
{
initialValues[variables[initialValue.Identifier]] = ((Float)right).Value;
}
else
{
//add error message
compilerErrors.Add(new ErrorMessage("Определение начального приближения переменной" +
initialValue.Identifier + " не является константным выражением"));
}
}
else
{
//add error message
compilerErrors.Add(new ErrorMessage("Определение начального приближения несуществующей переменной"));
}
}
//check that number of variables = number of equations
if (variableNames.Count != equations.Count)
{
compilerErrors.Add(new ErrorMessage($"Количество переменных не совпадает с количеством уравнений: {variableNames.Count} переменных, {equations.Count} уравнений"));
}
if (equations.Count == 0)
{
compilerErrors.Add(new ErrorMessage("Пустая система уравнений"));
}
if (compilerErrors.Count > 0)
{
throw new CompilerException(compilerErrors);
//fall back;
}
Expression.Compiler expCompiler = new Expression.Compiler(variables);
for (int i = 0; i < equations.Count; i++)
{
rpnEquations.Add(expCompiler.Compile(equations[i]));
}
RPNExpression [,] jacobiMatrix = new RPNExpression[equations.Count, equations.Count];
Expression.DifferentiationVisitor difVisitor = new Expression.DifferentiationVisitor();
int j = 0;
foreach (var equation in equations)
{
int i = 0;
foreach (var variable in variableNames)
{
//find derivative for variable
Expression.Expression derivative = ExpressionSimplifier.Simplify(difVisitor.Differentiate(equation, variable));
//simplify derivative expression
RPNExpression exp = expCompiler.Compile(derivative);
jacobiMatrix[i, j] = exp;
i++;
}
j++;
}
NonlinearEquationDescription ned = new NonlinearEquationDescription(initialValues.ToArray(), variableNames.ToArray(),
rpnEquations, jacobiMatrix);
return(ned);
}