TMtxExpression.DefineVector Method

Overload List

#	Signature	Description
1	function DefineVector(const AVarName: string): TVectorValue;	Use internal vector.
2	function DefineVector(const AVarName: string; const Vec: TVec): TVectorValue;	Defines new vector variable.

Overload 1: function DefineVector(const AVarName: string): TVectorValue;

Use internal vector.

#	Name	Type	Description
1	AVarName	string

Returns: TVectorValue

Overload 2: function DefineVector(const AVarName: string; const Vec: TVec): TVectorValue;

Defines new vector variable.

#	Name	Type	Description
1	AVarName	string
2	Vec	TVec

Returns: TVectorValue

Remarks:

If variable with name AVarName already was definded, it is redefined and all expressions which contain the symbol AVarName will be recompiled before the next evaluation. External vector may be assigned as values holder. If external vector is not assigned, internal vector will be used.

Examples

uses MtxParseExpr, MtxExpr, MtxParseClass;

procedure Example(MyParser: TMtxExpression);
var x: TVectorValue;
s: TDoubleValue;
res: Vector;
begin
    // 1. Define variables
    x := MyParser.DefineVector('x');
    s := MyParser.DefineDouble('s');

    // 2. Set values
    x.Value.SetIt(false,[1,-1,1]);
    s.DoubleValue := 0.5;

    // 3. Add formula and evaluate,
    MyParser.AddExpr('-s*x');
    res := MyParser.EvaluateVector;
    // res = (-0.5,0.5, -0.5)
end;