Detailed Description

template<class vec_t>
class o2scl::interp2_neigh< vec_t >

This class performs nearest-neighbor interpolation when the data points are not arranged in a specified order (i.e. not on a grid). For a set of data ${x_i,y_i,f_i}$ , the value of $ f $ is predicted given a new value of x and y. Distances are determined with

$d_{ij} = \sqrt{\left(\frac{x_i-x_j}{\Delta x}\right)^2 + \left(\frac{y_i-y_j}{\Delta y}\right)^2}$

The values $\Delta_x$ and $\Delta_y$ are specified in x_scale and y_scale, respectively. If these values are negative (the default) then they are computed with $\Delta x = x_{\mathrm{max}}-x_{\mathrm{min}}$ and $\Delta y = y_{\mathrm{max}}-y_{\mathrm{min}}$ .

This class stores pointers to the data, not a copy. The data can be changed between interpolations without an additional call to set_data(), but the scales may need to be recomputed with compute_scale().

The vector type can be any type with a suitably defined operator[].

Note: This class operates by performing a ${\cal O}(N)$ brute-force search to find the closest points.

Idea for Future:: Make a parent class for this and o2scl::interp2_planar.

Idea for Future:: Maybe interpm_idw subsumes this functionality and makes this class obsolete? Or is this specialization particularly efficient?

Definition at line 74 of file interp2_neigh.h.

Public Types
typedef boost::numeric::ublas::vector< double >	ubvector

typedef boost::numeric::ublas::vector< size_t >	ubvector_size_t

Public Member Functions
void	compute_scale ()
	Find scaling.

void	set_data (size_t n_points, vec_t &x, vec_t &y, vec_t &f)
	Initialize the data for the neigh interpolation. More...

double	eval (double x, double y) const
	Perform the interpolation.

double	operator() (double x, double y) const
	Perform the interpolation.

template<class vec2_t >
double	operator() (vec2_t &v) const
	Perform the planar interpolation using the first two elements of `v` as input.

void	eval_point (double x, double y, double &f, size_t &i1, double &x1, double &y1) const
	Interpolation returning the closest point. More...

Public Attributes
double	x_scale
	The user-specified x scale (default -1)

double	y_scale
	The user-specified y scale (default -1)

Protected Attributes
double	dx
	The scale in the x direction.

double	dy
	The scale in the y direction.

size_t	np
	The number of points.

vec_t *	ux
	The x-values.

vec_t *	uy
	The y-values.

vec_t *	uf
	The f-values.

bool	data_set
	True if the data has been specified.

Member Function Documentation

◆ eval_point()

template<class vec_t >

void o2scl::interp2_neigh< vec_t >::eval_point	(	double	x,
		double	y,
		double &	f,
		size_t &	i1,
		double &	x1,
		double &	y1
	)		const

inline

This function interpolates x and y into the data returning f. It also returns the closest x- and y-values found.

Definition at line 182 of file interp2_neigh.h.

◆ set_data()

template<class vec_t >

void o2scl::interp2_neigh< vec_t >::set_data	(	size_t	n_points,
		vec_t &	x,
		vec_t &	y,
		vec_t &	f
	)

inline

This function will call the error handler if n_points is zero.

Definition at line 138 of file interp2_neigh.h.

The documentation for this class was generated from the following file:

/home/awsteiner/wcs/o2scl/src/other/interp2_neigh.h

Detailed Description

template<class vec_t> class o2scl::interp2_neigh< vec_t >

Public Types

Public Member Functions

Public Attributes

Protected Attributes

Member Function Documentation

◆ eval_point()

◆ set_data()

template<class vec_t>
class o2scl::interp2_neigh< vec_t >