ACE_Stats Class Reference

Provides simple statistical analysis. More...

#include <Stats.h>

Collaboration diagram for ACE_Stats:

List of all members.

Public Member Functions
	ACE_Stats (void)
	Default constructor.
int	sample (const ACE_INT32 value)
ACE_UINT32	samples (void) const
	Access the number of samples provided so far.
ACE_INT32	min_value (void) const
	Value of the minimum sample provided so far.
ACE_INT32	max_value (void) const
	Value of the maximum sample provided so far.
void	mean (ACE_Stats_Value &mean, const ACE_UINT32 scale_factor=1)
int	std_dev (ACE_Stats_Value &std_dev, const ACE_UINT32 scale_factor=1)
int	print_summary (const u_int precision, const ACE_UINT32 scale_factor=1, FILE *=stdout) const
void	reset (void)
	Initialize internal state.
void	dump (void) const
	Print summary statistics to stdout.
Static Public Member Functions
static void	quotient (const ACE_UINT64 dividend, const ACE_UINT32 divisor, ACE_Stats_Value &quotient)
	Utility division function, for ACE_UINT64 dividend.
static void	quotient (const ACE_Stats_Value &dividend, const ACE_UINT32 divisor, ACE_Stats_Value &quotient)
	Utility division function, for ACE_Stats_Value dividend.
static void	square_root (const ACE_UINT64 n, ACE_Stats_Value &square_root)
Protected Attributes
u_int	overflow_
ACE_UINT32	number_of_samples_
	Number of samples.
ACE_INT32	min_
	Minimum sample value.
ACE_INT32	max_
	Maximum sample value.
ACE_Unbounded_Queue< ACE_INT32 >	samples_
	The samples.

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Detailed Description

Provides simple statistical analysis.

Simple statistical analysis package. Prominent features are:

1. It does not use any floating point arithmetic.
2. It handles positive and/or negative sample values. The sample value type is ACE_INT32.
3. It uses 64 bit unsigned, but not 64 bit signed, quantities internally.
4. It checks for overflow of internal state.
5. It has no static variables of other than built-in types.

Example usage:

 * ACE_Stats stats;
 * for (u_int i = 0; i < n; ++i)
 * {
 * const ACE_UINT32 sample = ...;
 * stats.sample (sample);
 * }
 * stats.print_summary (3);
 * 

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Constructor & Destructor Documentation

ACE_Stats::ACE_Stats

(

void

)

[inline]

Default constructor.

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Member Function Documentation

void ACE_Stats::dump

(

void

)

const [inline]

Print summary statistics to stdout.

ACE_INT32 ACE_Stats::max_value

(

void

)

const [inline]

Value of the maximum sample provided so far.

void ACE_Stats::mean	(	ACE_Stats_Value &	mean,
		const ACE_UINT32	scale_factor = 1
	)

Access the mean of all samples provided so far. The fractional part is to the specified number of digits. E.g., 3 fractional digits specifies that the fractional part is in thousandths.

ACE_INT32 ACE_Stats::min_value

(

void

)

const [inline]

Value of the minimum sample provided so far.

int ACE_Stats::print_summary	(	const u_int	precision,
		const ACE_UINT32	scale_factor = 1,
		FILE *	file = stdout
	)		const

Print summary statistics. If scale_factor is not 1, then the results are divided by it, i.e., each of the samples is scaled down by it. If internal overflow is reached with the specified scale factor, it successively tries to reduce it. Returns -1 if there is overflow even with a 0 scale factor.

void ACE_Stats::quotient	(	const ACE_UINT64	dividend,
		const ACE_UINT32	divisor,
		ACE_Stats_Value &	quotient
	)		[static]

Utility division function, for ACE_UINT64 dividend.

void ACE_Stats::quotient	(	const ACE_Stats_Value &	dividend,
		const ACE_UINT32	divisor,
		ACE_Stats_Value &	quotient
	)		[static]

Utility division function, for ACE_Stats_Value dividend.

void ACE_Stats::reset

(

void

)

Initialize internal state.

int ACE_Stats::sample

(

const ACE_INT32

value

)

Provide a new sample. Returns 0 on success, -1 if it fails due to running out of memory, or to rolling over of the sample count.

ACE_UINT32 ACE_Stats::samples

(

void

)

const [inline]

Access the number of samples provided so far.

void ACE_Stats::square_root	(	const ACE_UINT64	n,
		ACE_Stats_Value &	square_root
	)		[static]

Sqrt function, which uses an oversimplified version of Newton's method. It's not fast, but it doesn't require floating point support.

int ACE_Stats::std_dev	(	ACE_Stats_Value &	std_dev,
		const ACE_UINT32	scale_factor = 1
	)

Access the standard deviation, whole and fractional parts. See description of {mean} method for argument descriptions.

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Member Data Documentation

ACE_INT32 ACE_Stats::max_ [protected]

Maximum sample value.

ACE_INT32 ACE_Stats::min_ [protected]

Minimum sample value.

ACE_UINT32 ACE_Stats::number_of_samples_ [protected]

Number of samples.

u_int ACE_Stats::overflow_ [protected]

Internal indication of whether there has been overflow. Contains the errno corresponding to the cause of overflow.

ACE_Unbounded_Queue<ACE_INT32> ACE_Stats::samples_ [protected]

The samples.

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

• Stats.h
• Stats.cpp
• Stats.inl