gini.cc File Reference

Gini coefficient. More...

#include "sqlstat.h"
#include <set>

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Classes
struct	sqlstat::Item
struct	sqlstat::ItemComperator
struct	sqlstat::gini_storage

Typedefs
typedef std::multiset< Item, ItemComperator >	sqlstat::ItemSet

Functions
my_bool	gini_init (UDF_INIT *initid, UDF_ARGS *args, char *message)
	Called before first usage of function. More...
void	gini_reset (UDF_INIT *initid, UDF_ARGS *args, char *is_null, char *error)
	Reset function and add first group member Calls clear and add. More...
void	gini_clear (UDF_INIT *initid, char *is_null, char *error)
	Called at start of group. More...
void	gini_add (UDF_INIT *initid, UDF_ARGS *args, char *is_null, char *error)
	Add a member of the group. More...
double	gini (UDF_INIT *initid, UDF_ARGS *args, char *is_null, char *error)
	Retrieve gini. Called at end of group. More...
void	gini_deinit (UDF_INIT *initid)
	Called after last access to function. More...

Detailed Description

Gini coefficient.

CREATE AGGREGATE FUNCTION gini RETURNS REAL SONAME 'libsqlstat.so';
SELECT gini(x, w) FROM mytab;
DROP FUNCTION gini;

Definition in file gini.cc.

Function Documentation

double gini	(	UDF_INIT *	initid,
		UDF_ARGS *	args,
		char *	is_null,
		char *	error
	)

Retrieve gini. Called at end of group.

Parameters

initid	function description
args	argument values
is_null	result is NULL
error	error occured

Returns

gini

Definition at line 176 of file gini.cc.

void gini_add	(	UDF_INIT *	initid,
		UDF_ARGS *	args,
		char *	is_null,
		char *	error
	)

Add a member of the group.

The counter and sums are updated

Parameters

initid	function description
args	argument values
is_null
error	error occured

Definition at line 146 of file gini.cc.

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void gini_clear	(	UDF_INIT *	initid,
		char *	is_null,
		char *	error
	)

Called at start of group.

The counter and sums are cleared.

Parameters

initid	function description
is_null
error	error message

Definition at line 129 of file gini.cc.

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gini_deinit

(

UDF_INIT *

initid

)

Called after last access to function.

Deallocate memory for counter and sums.

Parameters

initid

Definition at line 209 of file gini.cc.

my_bool gini_init	(	UDF_INIT *	initid,
		UDF_ARGS *	args,
		char *	message
	)

Called before first usage of function.

Check parameters.
Indicate type of return value.
Allocate memory for counter and sums.

Parameters

initid	function description
args	parameters
message	error message

Returns

success = 0

Definition at line 76 of file gini.cc.

void gini_reset	(	UDF_INIT *	initid,
		UDF_ARGS *	args,
		char *	is_null,
		char *	error
	)

Reset function and add first group member Calls clear and add.

Parameters

initid	function description
args	argument values
is_null
error	error message

Deprecated:

Reset is only called by MySQL 4.0 and below. It is implemented for backwards compatibility.

Definition at line 115 of file gini.cc.

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