CL-reduce_by_key

Functions
template<typename InputIterator1 , typename InputIterator2 , typename OutputIterator1 , typename OutputIterator2 >
pair< OutputIterator1, OutputIterator2 >	bolt::cl::reduce_by_key (control &ctl, InputIterator1 keys_first, InputIterator1 keys_last, InputIterator2 values_first, OutputIterator1 keys_output, OutputIterator2 values_output, const std::string &user_code="")
	reduce_by_key performs, on a sequence, a reduction of each sub-sequence as defined by equivalent keys; the BinaryFunction in this version is plus(), and the BinaryPredicate is equal_to().
template<typename InputIterator1 , typename InputIterator2 , typename OutputIterator1 , typename OutputIterator2 >
pair< OutputIterator1, OutputIterator2 >	bolt::cl::reduce_by_key (InputIterator1 keys_first, InputIterator1 keys_last, InputIterator2 values_first, OutputIterator1 keys_output, OutputIterator2 values_output, const std::string &user_code="")
template<typename InputIterator1 , typename InputIterator2 , typename OutputIterator1 , typename OutputIterator2 , typename BinaryPredicate >
pair< OutputIterator1, OutputIterator2 >	bolt::cl::reduce_by_key (control &ctl, InputIterator1 keys_first, InputIterator1 keys_last, InputIterator2 values_first, OutputIterator1 keys_output, OutputIterator2 values_output, BinaryPredicate binary_pred, const std::string &user_code="")
	reduce_by_key performs, on a sequence, a reduction of each sub-sequence as defined by equivalent keys; the BinaryFunction in this version is plus(). reduce_by_key is a generalization of reduce to key-value pairs. If the reduction operator is not commutative then bolt::reduce_by_key should not be used.
template<typename InputIterator1 , typename InputIterator2 , typename OutputIterator1 , typename OutputIterator2 , typename BinaryPredicate >
pair< OutputIterator1, OutputIterator2 >	bolt::cl::reduce_by_key (InputIterator1 keys_first, InputIterator1 keys_last, InputIterator2 values_first, OutputIterator1 keys_output, OutputIterator2 values_output, BinaryPredicate binary_pred, const std::string &user_code="")
template<typename InputIterator1 , typename InputIterator2 , typename OutputIterator1 , typename OutputIterator2 , typename BinaryPredicate , typename BinaryFunction >
pair< OutputIterator1, OutputIterator2 >	bolt::cl::reduce_by_key (control &ctl, InputIterator1 keys_first, InputIterator1 keys_last, InputIterator2 values_first, OutputIterator1 keys_output, OutputIterator2 values_output, BinaryPredicate binary_pred, BinaryFunction binary_op, const std::string &user_code="")
	reduce_by_key performs, on a sequence, a reduction of each sub-sequence as defined by equivalent keys; reduce_by_key is a generalization of reduce to key-value pairs. If the reduction operator is not commutative then bolt::reduce_by_key should not be used.
template<typename InputIterator1 , typename InputIterator2 , typename OutputIterator1 , typename OutputIterator2 , typename BinaryPredicate , typename BinaryFunction >
pair< OutputIterator1, OutputIterator2 >	bolt::cl::reduce_by_key (InputIterator1 keys_first, InputIterator1 keys_last, InputIterator2 values_first, OutputIterator1 keys_output, OutputIterator2 values_output, BinaryPredicate binary_pred, BinaryFunction binary_op, const std::string &user_code="")

Detailed Description

Function Documentation

template<typename InputIterator1 , typename InputIterator2 , typename OutputIterator1 , typename OutputIterator2 >

bolt::cl::pair< OutputIterator1, OutputIterator2 > bolt::cl::reduce_by_key	(	control &	ctl,
		InputIterator1	keys_first,
		InputIterator1	keys_last,
		InputIterator2	values_first,
		OutputIterator1	keys_output,
		OutputIterator2	values_output,
		const std::string &	user_code = ""
	)

reduce_by_key performs, on a sequence, a reduction of each sub-sequence as defined by equivalent keys; the BinaryFunction in this version is plus(), and the BinaryPredicate is equal_to().

Parameters

ctl	Optional Control structure to control command-queue, debug, tuning, etc. See bolt::cl::control.
keys_first	The first element of the key sequence.
keys_last	The last element of the key sequence.
values_first	The first element of the value sequence.
keys_output	The first element of the key output sequence.
values_output	The first element of the value output sequence.
user_code	A user-specified Optional string that is preppended to the generated OpenCL kernel.

Template Parameters

InputIterator1	is a model of Input Iterator.
InputIterator2	is a model of Input Iterator.
OutputIterator	is a model of Output Iterator.

Returns

result+(last1-first1).

Example:

#include "bolt/cl/reduce_by_key.h"
...

int keys[11] = { 0, 0, 0, 2, 2, 2, -5, -5, -5, -5, 6 };
int vals[11] = { 2, 2, 2, 2, 2, 2,  2,  2,  2,  2, 2 };
int keys_out[11];
int vals_out[11];

bolt::cl::control ctrl = control::getDefault();

bolt::cl::reduce_by_key( ctl, keys, keys+11, vals, keys_out, vals_out );
// keys_out => { 0, 2, -5, 6 }
// vals_out => { 6, 6, 8, 2 }

template<typename InputIterator1 , typename InputIterator2 , typename OutputIterator1 , typename OutputIterator2 , typename BinaryPredicate >

bolt::cl::pair< OutputIterator1, OutputIterator2 > bolt::cl::reduce_by_key	(	control &	ctl,
		InputIterator1	keys_first,
		InputIterator1	keys_last,
		InputIterator2	values_first,
		OutputIterator1	keys_output,
		OutputIterator2	values_output,
		BinaryPredicate	binary_pred,
		const std::string &	user_code = ""
	)

reduce_by_key performs, on a sequence, a reduction of each sub-sequence as defined by equivalent keys; the BinaryFunction in this version is plus(). reduce_by_key is a generalization of reduce to key-value pairs. If the reduction operator is not commutative then bolt::reduce_by_key should not be used.

Parameters

ctl	Optional Control structure to control command-queue, debug, tuning, etc. See bolt::cl::control.
keys_first	The first element of the key sequence.
keys_last	The last element of the key sequence.
values_first	The first element of the value sequence.
keys_output	The first element of the key output sequence.
values_output	The first element of the value output sequence.
binary_pred	Binary predicate which determines if two keys are equal.
user_code	A user-specified Optional string that is preppended to the generated OpenCL kernel.

Template Parameters

InputIterator1	is a model of Input Iterator.
InputIterator2	is a model of Input Iterator.
OutputIterator	is a model of Output Iterator.
BinaryPredicate	is a model of Binary Predicate.

Returns

pair(last of keys output, last of value output)

Example:

#include "bolt/cl/reduce_by_key.h"
...

int keys[11] = { 0, 0, 0, 2, 2, 2, -5, -5, -5, -5, 6 };
int vals[11] = { 2, 2, 2, 2, 2, 2,  2,  2,  2,  2, 2 };
int keys_out[11];
int vals_out[11];

bolt::cl::equal_to<int> eq;
bolt::cl::control ctrl = control::getDefault();

bolt::cl::reduce_by_key( ctl, keys, keys+11, vals, keys_out, vals_out, eq );
// keys_out => { 0, 2, -5, 6 }
// vals_out => { 6, 6, 8, 2 }

template<typename InputIterator1 , typename InputIterator2 , typename OutputIterator1 , typename OutputIterator2 , typename BinaryPredicate , typename BinaryFunction >

bolt::cl::pair< OutputIterator1, OutputIterator2 > bolt::cl::reduce_by_key	(	control &	ctl,
		InputIterator1	keys_first,
		InputIterator1	keys_last,
		InputIterator2	values_first,
		OutputIterator1	keys_output,
		OutputIterator2	values_output,
		BinaryPredicate	binary_pred,
		BinaryFunction	binary_op,
		const std::string &	user_code = ""
	)

reduce_by_key performs, on a sequence, a reduction of each sub-sequence as defined by equivalent keys; reduce_by_key is a generalization of reduce to key-value pairs. If the reduction operator is not commutative then bolt::reduce_by_key should not be used.

Parameters

ctl	Optional Control structure to control command-queue, debug, tuning, etc. See bolt::cl::control.
keys_first	The first element of the key sequence.
keys_last	The last element of the key sequence.
values_first	The first element of the value sequence.
keys_output	The first element of the key output sequence.
values_output	The first element of the value output sequence.
binary_pred	Binary predicate which determines if two keys are equal.
binary_op	Binary function for scanning transformed elements.
user_code	A user-specified Optional tring that is preppended to the generated OpenCL kernel.

Template Parameters

InputIterator1	is a model of Input Iterator.
InputIterator2	is a model of Input Iterator.
OutputIterator	is a model of Output Iterator.
BinaryPredicate	is a model of Binary Predicate.
BinaryFunction	is a model of Binary Function whose return type is convertible to OutputIterator's value_type.

Returns

pair(last of keys output, last of value output)

Example:

#include "bolt/cl/reduce_by_key.h"
...

int keys[11] = { 0, 0, 0, 2, 2, 2, -5, -5, -5, -5, 6 };
int vals[11] = { 2, 2, 2, 2, 2, 2,  2,  2,  2,  2, 2 };
int keys_out[11];
int vals_out[11];
bolt::cl::control ctl = control::getDefault();

bolt::cl::reduce_by_key( ctl, keys, keys+11, vals, keys_out, vals_out,bolt::cl::equal_to<int>(),
bolt::cl::plus<int>() );
// keys_out => { 0, 2, -5, 6 }
// vals_out => { 6, 6, 8, 2 }