zero< T > Class Template Reference

A small number. More...

#include <zero.h>

Collaboration diagram for zero< T >:

List of all members.

Public Member Functions

template<>

double val

template<>

double val

template<>

double val

template<>

double val

template<>

double val

template<>

double val

template<>

double val

template<>

double val

template<>

double val

template<>

double val

Static Public Member Functions

static boolc test (T const w)

Test if a number is zero.

Static Public Attributes

static T val

Generally a small positive number.

Detailed Description

template<typename T>
class zero< T >

A small number.

Numerical testing is subject to rounding errors. Often algorithms need to implement comparision testing where the in built rounding algorithms will fail.

Different zeros for different types can be defined. Do not instanciate the static member in a header, instead instanciate it in main.cpp file so that only one definition is generated.

Example

template<>
double zero<double>::val = 1E-20;

Definition at line 25 of file zero.h.

Member Function Documentation

template<typename T >

static boolc zero< T >::test ( T const w ) [inline, static]

Test if a number is zero.

Definition at line 33 of file zero.h.

References zero< T >::val().

00034   {
00035     if ((w<val)==false)
00036       return false;
00037 
00038     if ((T)0<w+val)
00039       return true;
00040 
00041     return false;
00042   }

template<>