SctData::CachedFunction1D Class Reference

Caches the values of a 1-d function into a look-up table so that it can later be evaluated very quickly. More...

#include <CachedFunction1D.h>

Public Member Functions
	CachedFunction1D (double min, double max, double delta, double(*function)(double)) throw ()
	Constructor creates a look-up table for the function in the range [min,max) with step delta between x-values.
	~CachedFunction1D () throw ()
	Deletes the table.
double	eval (double x) const throw ()
	evaluate the function by picking a value from the look-up table.
Private Member Functions
	CachedFunction1D () throw ()
	not allowed to do this.
CachedFunction1D &	operator= (const CachedFunction1D &) throw ()
	not allowed to do this.
void	makeTable () throw ()
	called by the constructor to make the look-up table.
Private Attributes
double	min
	min value of x for which the function is calculated.
double	max
	min value of x for which the function is calculated.
double	delta
	the step in x between points in the table.
double	invdelta
	cached value of 1/delta.
int	nvalue
	the number of values in the table.
double *	values
	the table itself.
double(*	function )(double)
	a pointer to the function itself.

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Detailed Description

Caches the values of a 1-d function into a look-up table so that it can later be evaluated very quickly.

Author:

Alan Barr

Date:

3 April 2003

Definition at line 15 of file CachedFunction1D.h.

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Constructor & Destructor Documentation

SctData::CachedFunction1D::CachedFunction1D (  double  min, double  max, double  delta, double(*)(double)  function )  throw ()

Constructor creates a look-up table for the function in the range [min,max) with step delta between x-values. e.g. CachedFunction1D(0., 1., 0.001, &TMath::erf ); Parameters: the  minimum x-value the  maximum x-value the  x step size -> decrease for better precision. the  address of the function ``double f(double x)'' Definition at line 5 of file CachedFunction1D.cpp.

SctData::CachedFunction1D::~CachedFunction1D (   )  throw ()

Deletes the table. Definition at line 16 of file CachedFunction1D.cpp. References values.

SctData::CachedFunction1D::CachedFunction1D (   )  throw () [private]

not allowed to do this.

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Member Function Documentation

double SctData::CachedFunction1D::eval (  double  x  )  const throw () [inline]

evaluate the function by picking a value from the look-up table. Parameters: the  value of the function at which to evaluate Returns: the appropriate value from the look-up table. if x<min or x>max then f(min) or f(max) are returned respectively. Definition at line 55 of file CachedFunction1D.h. References Sct::min(). Referenced by SctData::erf(), SctData::erfc(), and SctData::tophat(). Here is the call graph for this function:

void SctData::CachedFunction1D::makeTable (   )  throw () [private]

called by the constructor to make the look-up table. Definition at line 20 of file CachedFunction1D.cpp. References nvalue, and values.

CachedFunction1D& SctData::CachedFunction1D::operator= (  const CachedFunction1D &   )  throw () [private]

not allowed to do this.

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Field Documentation

double SctData::CachedFunction1D::delta [private]

the step in x between points in the table. Definition at line 47 of file CachedFunction1D.h.

double(* SctData::CachedFunction1D::function)(double) [private]

a pointer to the function itself.

double SctData::CachedFunction1D::invdelta [private]

cached value of 1/delta. Definition at line 48 of file CachedFunction1D.h.

double SctData::CachedFunction1D::max [private]

min value of x for which the function is calculated. Definition at line 46 of file CachedFunction1D.h.

double SctData::CachedFunction1D::min [private]

min value of x for which the function is calculated. Definition at line 45 of file CachedFunction1D.h.

int SctData::CachedFunction1D::nvalue [private]

the number of values in the table. Definition at line 49 of file CachedFunction1D.h. Referenced by makeTable().

double* SctData::CachedFunction1D::values [private]

the table itself. Definition at line 50 of file CachedFunction1D.h. Referenced by makeTable(), and ~CachedFunction1D().

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

• CachedFunction1D.h
• CachedFunction1D.cpp

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