create a c2_function which is a piecewise assembly of other c2_functions.The functions must have increasing, non-overlapping domains. Any empty space between functions will be filled with a linear interpolation. More...

#include <c2_function.hh>

Inheritance diagram for c2_piecewise_function_p< float_type >:

Public Member Functions
	c2_piecewise_function_p ()
	construct the container More...

virtual	~c2_piecewise_function_p ()
	destructor More...

virtual float_type	value_with_derivatives (float_type x, float_type yprime, float_type yprime2) const throw (c2_exception)
	get the value and derivatives. More...

void	append_function (const c2_function< float_type > &func) throw (c2_exception)
	append a new function to the sequence More...

Public Member Functions inherited from c2_function< float_type >
const std::string	cvs_header_vers () const
	get versioning information for the header file More...

const std::string	cvs_file_vers () const
	get versioning information for the source file More...

virtual	~c2_function ()
	destructor More...

float_type	operator() (float_type x) const throw (c2_exception)
	evaluate the function in the classic way, ignoring derivatives. More...

float_type	operator() (float_type x, float_type yprime, float_type yprime2) const throw (c2_exception)
	get the value and derivatives. More...

float_type	find_root (float_type lower_bracket, float_type upper_bracket, float_type start, float_type value, int error=0, float_type final_yprime=0, float_type *final_yprime2=0) const throw (c2_exception)
	solve f(x)==value very efficiently, with explicit knowledge of derivatives of the function More...

float_type	partial_integrals (std::vector< float_type > xgrid, std::vector< float_type > *partials=0, float_type abs_tol=1e-12, float_type rel_tol=1e-12, int derivs=2, bool adapt=true, bool extrapolate=true) const throw (c2_exception)
	for points in xgrid, adaptively return Integral[f(x),{x,xgrid[i],xgrid[i+1]}] and return in vector, along with sum More...

float_type	integral (float_type amin, float_type amax, std::vector< float_type > *partials=0, float_type abs_tol=1e-12, float_type rel_tol=1e-12, int derivs=2, bool adapt=true, bool extrapolate=true) const throw (c2_exception)
	a fully-automated integrator which uses the information provided by the get_sampling_grid() function to figure out what to do. More...

c2_piecewise_function_p < float_type > *	adaptively_sample (float_type amin, float_type amax, float_type abs_tol=1e-12, float_type rel_tol=1e-12, int derivs=2, std::vector< float_type > xvals=0, std::vector< float_type > yvals=0) const throw (c2_exception)
	create a c2_piecewise_function_p from c2_connector_function_p segments which is a representation of the parent function to the specified accuracy, but maybe much cheaper to evaluate More...

float_type	xmin () const
	return the lower bound of the domain for this function as set by set_domain() More...

float_type	xmax () const
	return the upper bound of the domain for this function as set by set_domain() More...

void	set_domain (float_type amin, float_type amax)
	set the domain for this function. More...

size_t	get_evaluations () const
	this is a counter owned by the function but which can be used to monitor efficiency of algorithms. More...

void	reset_evaluations () const
	reset the counter More...

void	increment_evaluations () const
	count evaluations More...

bool	check_monotonicity (const std::vector< float_type > &data, const char message[]) const throw (c2_exception)
	check that a vector is monotonic, throw an exception if not, and return a flag if it is reversed More...

virtual void	set_sampling_grid (const std::vector< float_type > &grid) throw (c2_exception)
	establish a grid of 'interesting' points on the function. More...

std::vector< float_type > *	get_sampling_grid_pointer () const
	get the sampling grid, which may be a null pointer More...

virtual void	get_sampling_grid (float_type amin, float_type amax, std::vector< float_type > &grid) const
	return the grid of 'interesting' points along this function which lie in the region requested More...

void	preen_sampling_grid (std::vector< float_type > *result) const
	clean up endpoints on a grid of points More...

void	refine_sampling_grid (std::vector< float_type > &grid, size_t refinement) const
	refine a grid by splitting each interval into more intervals More...

c2_function< float_type > &	normalized_function (float_type amin, float_type amax, float_type norm=1.0) const throw (c2_exception)
	create a new c2_function from this one which is normalized on the interval More...

c2_function< float_type > &	square_normalized_function (float_type amin, float_type amax, float_type norm=1.0) const throw (c2_exception)
	create a new c2_function from this one which is square-normalized on the interval More...

c2_function< float_type > &	square_normalized_function (float_type amin, float_type amax, const c2_function< float_type > &weight, float_type norm=1.0) const throw (c2_exception)
	create a new c2_function from this one which is square-normalized with the provided weight on the interval More...

c2_sum_p< float_type > &	operator+ (const c2_function< float_type > &rhs) const
	factory function to create a c2_sum_p from a regular algebraic expression. More...

c2_diff_p< float_type > &	operator- (const c2_function< float_type > &rhs) const
	factory function to create a c2_diff_p from a regular algebraic expression. More...

c2_product_p< float_type > &	operator* (const c2_function< float_type > &rhs) const
	factory function to create a c2_product_p from a regular algebraic expression. More...

c2_ratio_p< float_type > &	operator/ (const c2_function< float_type > &rhs) const
	factory function to create a c2_ratio_p from a regular algebraic expression. More...

c2_composed_function_p < float_type > &	operator() (const c2_function< float_type > &inner) const
	compose this function outside another. More...

float_type	get_trouble_point () const
	Find out where a calculation ran into trouble, if it got a nan. If the most recent computation did not return a nan, this is undefined. More...

void	claim_ownership () const
	increment our reference count. Destruction is only legal if the count is zero. More...

size_t	release_ownership_for_return () const throw (c2_exception)
	decrement our reference count. Do not destroy at zero. More...

void	release_ownership () const throw (c2_exception)
	decrement our reference count. If the count reaches zero, destroy ourself. More...

size_t	count_owners () const
	get the reference count, mostly for debugging More...

void	fill_fblock (c2_fblock< float_type > &fb) const throw (c2_exception)
	fill in a c2_fblock<float_type>... a shortcut for the integrator & sampler More...

Protected Attributes
std::vector< c2_const_ptr < float_type > >	functions

int	lastKLow

Protected Attributes inherited from c2_function< float_type >
std::vector< float_type > *	sampling_grid

bool	no_overwrite_grid

float_type	fXMin

float_type	fXMax

size_t	evaluations

float_type	bad_x_point
	this point may be used to record where a calculation ran into trouble More...

Additional Inherited Members
Protected Member Functions inherited from c2_function< float_type >
	c2_function (const c2_function< float_type > &src)

	c2_function ()

virtual void	set_sampling_grid_pointer (std::vector< float_type > &grid)

Detailed Description

template<typename float_type>
class c2_piecewise_function_p< float_type >

create a c2_function which is a piecewise assembly of other c2_functions.

The functions must have increasing, non-overlapping domains. Any empty space between functions will be filled with a linear interpolation.

Note: If you want a smooth connection, instead of the default linear interpolation, create a c2_connector_function_p to bridge the gap. The linear interpolation is intended to be a barely intelligent bridge, and may never get used by anyone.; The creation of the container results in the creation of an explicit sampling grid. If this is used with functions with a large domain, or which generate very dense sampling grids, it could eat a lot of memory. Do not abuse this by using functions which can generate gigantic grids.

See also: Sample Applications
c2_plugin_function_p page
c2_connector_function_p page
Adaptive sampling

The factory function c2_factory::piecewise_function() creates *new c2_piecewise_function_p

Definition at line 84 of file c2_function.hh.

Constructor & Destructor Documentation

template<typename float_type>

c2_piecewise_function_p< float_type >::c2_piecewise_function_p ( )

construct the container

template<typename float_type>

virtual c2_piecewise_function_p< float_type >::~c2_piecewise_function_p ( )

virtual

destructor

Member Function Documentation

template<typename float_type>

void c2_piecewise_function_p< float_type >::append_function	(	const c2_function< float_type > &	func	)
throw	(	c2_exception
	)

append a new function to the sequence

This takes a c2_function, and appends it onto the end of the piecewise collection. The domain of the function (which MUST be set) specifies the place it will be used in the final function. If the domain exactly abuts the domain of the previous function, it will be directly attached. If there is a gap, the gap will be filled in by linear interpolation.

Parameters

func	a c2_function with a defined domain to be appended to the collection

Referenced by LJZBLScreening().

template<typename float_type>

virtual float_type c2_piecewise_function_p< float_type >::value_with_derivatives	(	float_type	x,
		float_type *	yprime,
		float_type *	yprime2
	)		const
throw	(	c2_exception
	)

virtual

get the value and derivatives.

There is required checking for null pointers on the derivatives, and most implementations should operate faster if derivatives are not needed.

Parameters

[in]	x	the point at which to evaluate the function
[out]	yprime	the first derivative (if pointer is non-null)
[out]	yprime2	the second derivative (if pointer is non-null)