mfem::GSOPGSLIB Class Reference

Class for gather-scatter (gs) operations on Vectors based on corresponding global identifiers. More...

#include <gslib.hpp>

Public Types
enum	GSOp { ADD , MUL , MIN , MAX }
	Supported operation types. See class description. More...

Public Member Functions
	GSOPGSLIB (Array< long long > &ids)
	GSOPGSLIB (MPI_Comm comm_, Array< long long > &ids)
virtual	~GSOPGSLIB ()
void	UpdateIdentifiers (const Array< long long > &ids)
void	GS (Vector &senddata, GSOp op)

Protected Attributes
struct gslib::crystal *	cr
struct gslib::comm *	gsl_comm
struct gslib::gs_data *	gsl_data = NULL
int	num_ids

Detailed Description

Class for gather-scatter (gs) operations on Vectors based on corresponding global identifiers.

This functionality is useful for gs-ops on DOF values across processor boundary, where the global identifier would be the corresponding true DOF index. Operations currently supported are min, max, sum, and multiplication. Note: identifier 0 does not participate in the gather-scatter operation and a given identifier can be included multiple times on a given rank. For example, consider a vector, v:

• v = [0.3, 0.4, 0.25, 0.7] on rank1,
• v = [0.6, 0.1] on rank 2,
• v = [-0.2, 0.3, 0.7, 0.] on rank 3.

Consider a corresponding Array<int>, a:

• a = [1, 2, 3, 1] on rank 1,
• a = [3, 2] on rank 2,
• a = [1, 2, 0, 3] on rank 3.

A gather-scatter "minimum" operation, done as follows: GSOPGSLIB gs = GSOPGSLIB(MPI_COMM_WORLD, a); gs.GS(v, GSOp::MIN); would return into v:

• v = [-0.2, 0.1, 0., -0.2] on rank 1,
• v = [0., 0.1] on rank 2,
• v = [-0.2, 0.1, 0.7, 0.] on rank 3, where the values have been compared across all processors based on the integer identifier.

Definition at line 459 of file gslib.hpp.

Member Enumeration Documentation

GSOp

enum mfem::GSOPGSLIB::GSOp

Supported operation types. See class description.

Enumerator
ADD
MUL
MIN
MAX

Definition at line 477 of file gslib.hpp.

Constructor & Destructor Documentation

GSOPGSLIB() [1/2]

mfem::GSOPGSLIB::GSOPGSLIB

(

Array< long long > &

ids

)

Definition at line 2567 of file gslib.cpp.

GSOPGSLIB() [2/2]

mfem::GSOPGSLIB::GSOPGSLIB	(	MPI_Comm	comm_,
		Array< long long > &	ids )

Definition at line 2585 of file gslib.cpp.

~GSOPGSLIB()

mfem::GSOPGSLIB::~GSOPGSLIB ( )

virtual

Definition at line 2596 of file gslib.cpp.

Member Function Documentation

GS()

void mfem::GSOPGSLIB::GS	(	Vector &	senddata,
		GSOp	op )

Gather-Scatter operation on senddata. Must match length of unique identifiers used in the constructor. See class description.

Definition at line 2621 of file gslib.cpp.

UpdateIdentifiers()

void mfem::GSOPGSLIB::UpdateIdentifiers

(

const Array< long long > &

ids

)

Update the identifiers used for the gather-scatter operator. Same ids get grouped together and id == 0 does not participate. See class description.

Definition at line 2605 of file gslib.cpp.

Member Data Documentation

cr

struct gslib::crystal* mfem::GSOPGSLIB::cr

protected

Definition at line 462 of file gslib.hpp.

gsl_comm

struct gslib::comm* mfem::GSOPGSLIB::gsl_comm

protected

Definition at line 463 of file gslib.hpp.

gsl_data

struct gslib::gs_data* mfem::GSOPGSLIB::gsl_data = NULL

protected

Definition at line 464 of file gslib.hpp.

num_ids

int mfem::GSOPGSLIB::num_ids

protected

Definition at line 465 of file gslib.hpp.

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

• fem/gslib.hpp
• fem/gslib.cpp