ON_Sum Class Reference

Class for carefully adding long list of numbers. More...

#include <opennurbs_math.h>

Public Member Functions
	ON_Sum ()
	Creates a sum that is ready to be used. More...
void	Begin (double starting_value=0.0)
	If a sum is being used more than once, call Begin() before starting each sum. More...
void	operator+= (double x)
	Calls ON_Sum::Plus(x); More...
void	operator-= (double x)
	Calls ON_Sum::Plus(-x); More...
void	operator= (double x)
	Calls ON_Sum::Begin(x) More...
void	Plus (double x)
	Add x to the current sum. More...
void	Plus (double x, double dx)
	Add x to the current sum. More...
int	SummandCount () const
double	Total (double *error_estimate=nullptr)
	Calculates the total sum. More...

Detailed Description

Class for carefully adding long list of numbers.

Constructor & Destructor Documentation

ON_Sum()

ON_Sum::ON_Sum

(

)

Creates a sum that is ready to be used.

Member Function Documentation

Begin()

void ON_Sum::Begin

(

double

starting_value = 0.0

)

If a sum is being used more than once, call Begin() before starting each sum.

Parameters

starting_value

[in] Initial value of sum.

operator+=()

void ON_Sum::operator+=

(

double

x

)

Calls ON_Sum::Plus(x);

operator-=()

void ON_Sum::operator-=

(

double

x

)

Calls ON_Sum::Plus(-x);

operator=()

void ON_Sum::operator=

(

double

x

)

Calls ON_Sum::Begin(x)

Plus() [1/2]

void ON_Sum::Plus

(

double

x

)

Add x to the current sum.

Parameters

x	[in] value to add to the current sum.

Plus() [2/2]

void ON_Sum::Plus	(	double	x,
		double	dx
	)

Add x to the current sum.

Parameters

x	[in] value to add to the current sum.
dx	[in] symmetric uncertainty in x. (true value is in the range x-dx to x+dx

SummandCount()

int ON_Sum::SummandCount

(

)

const

Returns

Number of summands.

Total()

double ON_Sum::Total

(

double *

error_estimate = nullptr

)

Calculates the total sum.

Parameters

error_estimate

[out] if not nullptr, the returned value of *error_estimate is an estimate of the error in the sum.

Returns

Total of the sum.

You can get subtotals by mixing calls to Plus() and Total(). In delicate sums, some precision may be lost in the final total if you call Total() to calculate subtotals.