IfcNormalise

Semantic definitions at the function

Function Definition

NOTE Definition according to ISO/CD 10303-42:1992
This function returns a vector or direction whose components are normalized to have a sum of squares of 1.0. The output is of the same type (Direction or Vector, with the same units) as the input argument. If the input argument is not defined or of zero length then the output vector is undefined.

NOTE Function adapted from normalise defined in ISO 10303-42.

HISTORY New function in IFC1.5

Formal representations

EXPRESS Specification


FUNCTION IfcNormalise


  (Arg : IfcVectorOrDirection) 
    : IfcVectorOrDirection;
LOCAL
  Ndim : INTEGER;
  V    : IfcDirection
         := IfcRepresentationItem() || IfcGeometricRepresentationItem () || IfcDirection([1.,0.]); 
  Vec  : IfcVector 
         := IfcRepresentationItem() || IfcGeometricRepresentationItem () || IfcVector (
            IfcRepresentationItem() || IfcGeometricRepresentationItem () || IfcDirection([1.,0.]), 1.);
  Mag  : REAL;
  Result : IfcVectorOrDirection
         := V;
END_LOCAL;

  IF NOT EXISTS (Arg) THEN
    RETURN (?);
  ELSE
    IF 'IFCGEOMETRYRESOURCE.IfcVector' IN TYPEOF(Arg) THEN
      BEGIN
        Ndim := Arg\IfcVector.Dim;
	V.DirectionRatios := Arg\IfcVector.Orientation.DirectionRatios;
        Vec.Magnitude := Arg\IfcVector.Magnitude;
	Vec.Orientation := V;
        IF Arg\IfcVector.Magnitude = 0.0 THEN
          RETURN(?);
        ELSE
          Vec.Magnitude := 1.0;
        END_IF;
      END;
    ELSE
      BEGIN
        Ndim := Arg\IfcDirection.Dim;
        V.DirectionRatios := Arg\IfcDirection.DirectionRatios;
      END;
    END_IF;

    Mag := 0.0;
      REPEAT i := 1 TO Ndim;
        Mag := Mag + V.DirectionRatios[i]*V.DirectionRatios[i];
      END_REPEAT;
    IF Mag > 0.0 THEN
      Mag := SQRT(Mag);
      REPEAT i := 1 TO Ndim;
        V.DirectionRatios[i] := V.DirectionRatios[i]/Mag;
      END_REPEAT;
      IF 'IFCGEOMETRYRESOURCE.IfcVector' IN TYPEOF(arg) THEN
        Vec.Orientation := V;
        Result := Vec;
      ELSE
        Result := V;
      END_IF;
    ELSE
      RETURN(?);
    END_IF;
  END_IF;
  RETURN (Result);



END_FUNCTION;