1 // Copyright: Matra-Datavision 1991
2 // File: Expr_ArcTangent.cxx
3 // Created: Mon May 27 11:44:23 1991
4 // Author: Arnaud BOUZY
8 #include <Expr_ArcTangent.ixx>
9 #include <Expr_NumericValue.hxx>
10 #include <Expr_Tangent.hxx>
11 #include <Expr_Division.hxx>
12 #include <Expr_Square.hxx>
13 #include <Expr_Sum.hxx>
14 #include <Expr_Operators.hxx>
17 Expr_ArcTangent::Expr_ArcTangent (const Handle(Expr_GeneralExpression)& exp)
22 Handle(Expr_GeneralExpression) Expr_ArcTangent::ShallowSimplified () const
24 Handle(Expr_GeneralExpression) op = Operand();
25 if (op->IsKind(STANDARD_TYPE(Expr_NumericValue))) {
26 Handle(Expr_NumericValue) valop = Handle(Expr_NumericValue)::DownCast(op);
27 return new Expr_NumericValue(ATan(valop->GetValue()));
29 if (op->IsKind(STANDARD_TYPE(Expr_Tangent))) {
30 return op->SubExpression(1);
32 Handle(Expr_ArcTangent) me = this;
36 Handle(Expr_GeneralExpression) Expr_ArcTangent::Copy () const
38 return new Expr_ArcTangent(Expr::CopyShare(Operand()));
41 Standard_Boolean Expr_ArcTangent::IsIdentical (const Handle(Expr_GeneralExpression)& Other) const
43 if (!Other->IsKind(STANDARD_TYPE(Expr_ArcTangent))) {
44 return Standard_False;
46 Handle(Expr_GeneralExpression) op = Operand();
47 return op->IsIdentical(Other->SubExpression(1));
50 Standard_Boolean Expr_ArcTangent::IsLinear () const
52 if (ContainsUnknowns()) {
53 return Standard_False;
58 Handle(Expr_GeneralExpression) Expr_ArcTangent::Derivative (const Handle(Expr_NamedUnknown)& X) const
61 return new Expr_NumericValue(0.0);
63 Handle(Expr_GeneralExpression) op = Operand();
64 Handle(Expr_GeneralExpression) derop = op->Derivative(X);
66 Handle(Expr_Square) sq = new Expr_Square(Expr::CopyShare(op));
68 Handle(Expr_Sum) thesum = 1.0 + sq->ShallowSimplified();
70 // ArcTangent'(F(X)) = F'(X)/(1+F(X)2)
71 Handle(Expr_Division) thediv = derop / thesum->ShallowSimplified();
73 return thediv->ShallowSimplified();
76 Standard_Real Expr_ArcTangent::Evaluate(const Expr_Array1OfNamedUnknown& vars, const TColStd_Array1OfReal& vals) const
78 return ::ATan(Operand()->Evaluate(vars,vals));
81 TCollection_AsciiString Expr_ArcTangent::String() const
83 TCollection_AsciiString str("ATan(");
84 str += Operand()->String();