#### IfcNormalise

##### Semantic definitions at the function

Function Definition

Definition from 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 Corresponding STEP function: normalise. Please refer to ISO/IS 10303-42:1994, p.105 for the final definition of the formal standard.
> HISTORY New function in IFC Release 1.5

##### 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
Ndim := Arg.Dim;
IF 'IFCGEOMETRYRESOURCE.IFCVECTOR' IN TYPEOF(Arg) THEN
BEGIN
V.DirectionRatios := Arg\IfcVector.Orientation.DirectionRatios;
Vec.Magnitude := Arg\IfcVector.Magnitude;
Vec.Orientation := V;
IF Arg.Magnitude = 0.0 THEN
RETURN(?);
ELSE
Vec.Magnitude := 1.0;
END_IF;
END;
ELSE
V.DirectionRatios := Arg.DirectionRatios;
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;

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