CubicSpline2d Class Reference

cubic spline interpolation as described in R.L. Burden, J.D. Faires, Numerical Analysis, 4th ed. PWS-Kent, 1989, ISBN 0-53491-585-X, pp. 126-131. More...

#include <OpenMS/MATH/MISC/CubicSpline2d.h>

Collaboration diagram for CubicSpline2d:

Public Member Functions
	CubicSpline2d (const std::vector< double > &x, const std::vector< double > &y)
	constructor of spline interpolation More...
	CubicSpline2d (const std::map< double, double > &m)
	constructor of spline interpolation More...
double	eval (double x) const
	evaluates the spline at position x More...
double	derivatives (double x, unsigned order) const
	evaluates derivative of spline at position x More...

Private Member Functions
void	init_ (const std::vector< double > &x, const std::vector< double > &y)
	initialize the spline More...

Private Attributes
std::vector< double >	a_
	constant spline coefficients More...
std::vector< double >	b_
	linear spline coefficients More...
std::vector< double >	c_
	quadratic spline coefficients More...
std::vector< double >	d_
	cubic spline coefficients More...
std::vector< double >	x_
	knots More...

Detailed Description

cubic spline interpolation as described in R.L. Burden, J.D. Faires, Numerical Analysis, 4th ed. PWS-Kent, 1989, ISBN 0-53491-585-X, pp. 126-131.

Construction of the spline takes by far the most time. Evaluating it is rather fast (one evaluation is about 50x faster than construction – depending on number of points etc.).

Constructor & Destructor Documentation

CubicSpline2d() [1/2]

CubicSpline2d	(	const std::vector< double > &	x,
		const std::vector< double > &	y
	)

constructor of spline interpolation

The coordinates must match by index. Both vectors must be the same size and sorted in x. Sortedness in x is required for

See also

SplinePackage.

Parameters

x	x-coordinates of input data points (knots)
y	y-coordinates of input data points

CubicSpline2d() [2/2]

CubicSpline2d

(

const std::map< double, double > &

m

)

constructor of spline interpolation

Parameters

m	(x,y) coordinates of input data points

Member Function Documentation

derivatives()

double derivatives	(	double	x,
		unsigned	order
	)		const

evaluates derivative of spline at position x

Parameters

x	x-position
order	order of the derivative Only order 1 or 2 make sense for cubic splines.

eval()

double eval

(

double

x

)

const

evaluates the spline at position x

Parameters

x	x-position

init_()

void init_ ( const std::vector< double > &  x, const std::vector< double > &  y  )

private

initialize the spline

Parameters

x	x-coordinates of input data points (knots)
y	y-coordinates of input data points

Member Data Documentation

a_

std::vector<double> a_

private

constant spline coefficients

b_

std::vector<double> b_

private

linear spline coefficients

c_

std::vector<double> c_

private

quadratic spline coefficients

d_

std::vector<double> d_

private

cubic spline coefficients

x_

std::vector<double> x_

private

knots