-/*!
- * \brief This class provides interface for a density function
- */
-class Function
-{
-public:
- Function(bool expMode) : _expMode(expMode) {}
- double operator() (double t) const;
- virtual bool IsReady() const = 0;
-protected:
- virtual double compute(double t) const = 0;
-private:
- bool _expMode;
-};
-
-/*!
- * \brief This class provides computation of density function given by a table
- */
-class TabFunction: public Function
-{
-public:
- TabFunction(const vector<double>& table, bool expMode);
- virtual bool IsReady() const;
-protected:
- virtual double compute(double t) const;
-private:
- const vector<double>& _table;
-};
-
-/*!
- * \brief This class provides computation of density function given by an expression
- */
-class ExprFunction: public Function
-{
-public:
- ExprFunction(const char* expr, bool expMode);
- virtual bool IsReady() const;
-protected:
- virtual double compute(double t) const;
-private:
- Handle(Expr_GeneralExpression) _expression;
- Expr_Array1OfNamedUnknown _var;
- mutable TColStd_Array1OfReal _val;
-};
-
-double Function::operator() (double t) const
-{
- double res = compute(t);
- if (_expMode)
- res = pow(10, res);
- return res;
-}
-
-TabFunction::TabFunction(const vector<double>& table, bool expMode)
- : Function(expMode),
- _table(table)
-{
-}
-
-bool TabFunction::IsReady() const
-{
- return true;
-}
-
-double TabFunction::compute (double t) const
-{
- //find place of <t> in table
- int i;
- for (i=0; i < _table.size()/2; i++)
- if (_table[i*2] > t)
- break;
- if (i >= _table.size()/2)
- i = _table.size()/2 - 1;
-
- if (i == 0)
- return _table[1];
-
- // interpolate function value on found interval
- // (t - x[i-1]) / (x[i] - x[i-1]) = (y - f[i-1]) / (f[i] - f[i-1])
- // => y = f[i-1] + (f[i] - f[i-1]) * (t - x[i-1]) / (x[i] - x[i-1])
- double x1 = _table[(i-1)*2];
- double x2 = _table[i*2];
- double y1 = _table[(i-1)*2+1];
- double y2 = _table[i*2+1];
- if (x2 - x1 < Precision::Confusion())
- throw SALOME_Exception("TabFunction::compute : confused points");
- return y1 + (y2 - y1) * ((t - x1) / (x2 - x1));
-}
-
-ExprFunction::ExprFunction(const char* expr, bool expMode)
- : Function(expMode),
- _var(1,1),
- _val(1,1)
-{
- Handle( ExprIntrp_GenExp ) gen = ExprIntrp_GenExp::Create();
- gen->Process(TCollection_AsciiString((char*)expr));
- if (gen->IsDone())
- {
- _expression = gen->Expression();
- _var(1) = new Expr_NamedUnknown("t");
- }
-}
-
-bool ExprFunction::IsReady() const
-{
- return !_expression.IsNull();
-}
-
-double ExprFunction::compute (double t) const
-{
- ASSERT(!_expression.IsNull());
- _val(1) = t;
- return _expression->Evaluate(_var, _val);
-}
-
-//================================================================================
-/*!
- * \brief Compute next abscissa when two previous ones are given
- * \param sm2 - before previous abscissa
- * \param sm1 - previous abscissa
- * \param func - function of density
- * \param reverse - the direction of next abscissa, increase (0) or decrease (1)
- * \retval double - the new abscissa
- *
- * The abscissa s is given by the formulae
- *
- * ....|--------|----------------|.....
- * sm2 sm1 s
- *
- * func(sm2) / func(sm1) = (sm1-sm2) / (s-sm1)
- * => (s-sm1) * func(sm2) = (sm1-sm2) * func(sm1)
- * => s = sm1 + (sm1-sm2) * func(sm1) / func(sm2)
- */
-//================================================================================
-
-static double nextAbscissa(double sm2, double sm1, const Function& func, int reverse)
-{
- if (reverse)
- {
- sm1 = 1.0 - sm1;
- sm2 = 1.0 - sm2;
- }
- return sm1 + (sm1-sm2) * func(sm1) / func(sm2);
-}
-
-//================================================================================
-/*!
- * \brief Compute distribution of points on a curve following the law of a function
- * \param C3d - the curve to discretize
- * \param first - the first parameter on the curve
- * \param last - the last parameter on the curve
- * \param theReverse - flag indicating that the curve must be reversed
- * \param nbSeg - number of output segments
- * \param func - the function f(t)
- * \param theParams - output points
- * \retval bool - true if success
- */
-//================================================================================
-