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4.2.2.1.4 Cosine Spiral Transition Segment

The cosine spiral transition segment is a special case of a spiral where the curvature rate of change is a cosine function and the terms are dependent on the length L measured from the inflection point. The parameter value is defined as the deflection i.e. bearing angle &Theta.

The values of its individual terms dependent on segment length L: CosineTerm = L ConstantTerm = 1

The following diagram shows the generic classes and relationships used when applying this concept.

G <a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCurveSegment.htm'>IfcCurveSegment</a> IfcCurveSegment      LayerAssignment [0:1]      StyledByItem [0:1] 1. Transition [1:1]      UsingCurves [1:?] 2. Placement [1:1] 3. SegmentStart [1:1] 4. SegmentLength [1:1] 5. ParentCurve [1:1] <a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCosineSpiral.htm'>IfcCosineSpiral</a> IfcCosineSpiral      LayerAssignment [0:1]      StyledByItem [0:1] 1. Position [1:1] 2. CosineTerm [1:1] 3. ConstantTerm [0:1] <a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCurveSegment.htm'>IfcCurveSegment</a>:ParentCurve1-><a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCosineSpiral.htm'>IfcCosineSpiral</a>:IfcCosineSpiral0 IfcLengthMeasure_0 IfcLengthMeasure <a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCurveSegment.htm'>IfcCurveSegment</a>:SegmentStart1->IfcLengthMeasure_0:IfcLengthMeasure0 IfcLengthMeasure_1 IfcLengthMeasure <a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCurveSegment.htm'>IfcCurveSegment</a>:SegmentLength1->IfcLengthMeasure_1:IfcLengthMeasure0 <a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcLengthMeasure.htm'>IfcLengthMeasure</a> IfcLengthMeasure <a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCosineSpiral.htm'>IfcCosineSpiral</a>:CosineTerm1-><a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcLengthMeasure.htm'>IfcLengthMeasure</a>:IfcLengthMeasure0 <a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcReal.htm'>IfcReal</a> IfcReal <a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcCosineSpiral.htm'>IfcCosineSpiral</a>:ConstantTerm1-><a href='/IFC/RELEASE/IFC4x3/HTML/lexical/IfcReal.htm'>IfcReal</a>:IfcReal0
Figure 4.2.2.1.4.A

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