class ROOT::Math::Interpolator


      Class for performing function interpolation of points.
      The class is instantiated with an interpolation methods, passed as an enumeration in the constructor.
      See Interpolation::Type for the available interpolation algorithms, which are implemented using GSL.
      See also the <A HREF=http://www.gnu.org/software/gsl/manual/html_node/Interpolation.html">GSL manual</A> for more information.
      The class provides additional methods for computing derivatives and integrals of interpolating functions.

      This class does not support copying.
      @ingroup Interpolation

Function Members (Methods)

public:

virtual	~Interpolator()
double	Deriv(double x) const
double	Deriv2(double x) const
double	Eval(double x) const
double	Integ(double a, double b) const
ROOT::Math::Interpolator	Interpolator(unsigned int ndata = 0, ROOT::Math::Interpolation::Type type = Interpolation::kCSPLINE)
ROOT::Math::Interpolator	Interpolator(const vector<double>& x, const vector<double>& y, ROOT::Math::Interpolation::Type type = Interpolation::kCSPLINE)
bool	SetData(const vector<double>& x, const vector<double>& y)
bool	SetData(unsigned int ndata, const double* x, const double* y)
string	Type() const
string	TypeGet() const

private:

ROOT::Math::Interpolator	Interpolator(const ROOT::Math::Interpolator&)
ROOT::Math::Interpolator&	operator=(const ROOT::Math::Interpolator&)

Data Members

private:

ROOT::Math::GSLInterpolator*	fInterp	pointer to GSL interpolator class

Class Charts

Inheritance Inherited Members Includes Libraries

Function documentation

Interpolator(unsigned int ndata = 0, ROOT::Math::Interpolation::Type type = Interpolation::kCSPLINE)

      Constructs an interpolator class from  number of data points and with Interpolation::Type type.
      The data can be set later on with the SetData method.
      In case the data size is not known, better using the default of zero or the next constructor later on.
      The defult interpolation type is Cubic spline

Interpolator(const vector<double>& x, const vector<double>& y, ROOT::Math::Interpolation::Type type = Interpolation::kCSPLINE)

      Constructs an interpolator class from vector of data points \f$ (x_i, y_i )\f$ and with Interpolation::Type type.
      The method will compute a continous interpolating function \f$ y(x) \f$ such that \f$ y_i = y ( x_i )\f$.
      The defult interpolation type is Cubic spline

virtual ~Interpolator()

Interpolator(const ROOT::Math::Interpolator& )

 usually copying is non trivial, so we make this unaccessible

bool SetData(const vector<double>& x, const vector<double>& y)

      Set the data vector ( x[] and y[] )
      To be efficient, the size of the data must be the same of the value used in the constructor (ndata)
      If this is not  the case a new re-initialization is performed with the new data size

bool SetData(unsigned int ndata, const double* x, const double* y)

      Set the data vector ( x[] and y[] )
      To be efficient, the size of the data must be the same of the value used when  constructing the class (ndata)
      If this is not  the case a new re-initialization is performed with the new data size.

double Eval(double x) const

      Return the interpolated value at point x

double Deriv(double x) const

      Return the derivative of the interpolated function at point x

double Deriv2(double x) const

      Return the second derivative of the interpolated function at point x

double Integ(double a, double b) const

      Return the Integral of the interpolated function over the range [a,b]

std::string Type() const

      Return the type of interpolation method

std::string TypeGet() const