#include <CE_Multigrid.h>

Inheritance diagram for CE_Multigrid:

Public Member Functions
	CE_Multigrid ()

	~CE_Multigrid () override

	CE_Multigrid (const CE_Multigrid &)=default

CE_Multigrid &	operator= (const CE_Multigrid &)=default

void	init (const UT_Vector3I &res, const UT_Vector3 &spacing, const UT_Vector3I &boundaries_neg, const UT_Vector3I &boundaries_pos, int level=0, UT_Vector3I odd_coarsenings=UT_Vector3I(0, 0, 0))
	Initialize array to given size, spacing, and boundary conditions. More...

void	initFromVoxels (const UT_VoxelArrayF &f, const UT_Vector3 &spacing, const UT_Vector3I &boundaries_neg, const UT_Vector3I &boundaries_pos)

void	updateBoundaryConditions (bool struts=false) const

int	getMaxCoarse (int min_per_axis) const

int	getLevel () const
	Returns a grid's level within the multigrid hierarchy. More...

UT_Vector3I	getParity () const
	Returns a vector containing the odd/even parity for each axis. More...

void	match (const CE_Multigrid &src)

void	subtractApplyLaplacian (CE_Multigrid &x, CE_Multigrid &r) const
	Computes rhe residual r = b - A * x, where b == *this. More...

void	computeResidualNorms (const CE_Multigrid &x, fpreal64 &norminf, fpreal64 &norm2) const

void	smoothLaplacianGaussSeidel (CE_Multigrid &x, int iterations=1, bool use_small=true) const

bool	smoothLaplacianGaussSeidelSmall (CE_Multigrid &x, int iterations=1) const

void	directSolve (CE_Multigrid &x) const

void	coarsenAlongAxis (CE_Multigrid &uh, int axis) const

UT_Vector3I	coarsen (int min_per_axis, CE_Multigrid &uh) const
	Coarsen this grid into a lower resolution version of the grid. More...

void	interpolateAlongAxis (CE_Multigrid &u, int axis) const

void	interpolate (const UT_Vector3I &interpolate_axis, const UT_Vector3I &parity, CE_Multigrid &u) const

void	vcycle (int min_per_axis, int n_smooth_down, int n_smooth_up, CE_Multigrid &x, bool smooth_top_level_down=true) const

void	fullMultigrid (int min_per_axis, int n_smooth_down, int n_smooth_up, CE_Multigrid &x) const

int	solvePoisson (fpreal64 abstol, fpreal64 reltol, int miniter, int maxiter, CE_Multigrid &x, UT_ValArray< fpreal64 > resnorminf, UT_ValArray< fpreal64 > resnorm2, bool finish_between_iters=false, bool start_fmg=true) const

Public Member Functions inherited from CE_Grid
	CE_Grid ()

	CE_Grid (const CE_Grid &src)

virtual	~CE_Grid ()

const cl::Buffer &	buffer () const

bool	hasBuffer () const
	If the current OpenCL buffer is valid. More...

bool	isValid () const

exint	getDeviceMemoryUsage () const

void	size (int xres, int yres, int zres, int xghost=1, int yghost=1, int zghost=1, int xpad=1, int ypad=1, int zpad=1)

int	getXRes () const

int	getYRes () const

int	getZRes () const

int	getRes (int dim) const

UT_Vector3I	getRes () const

UT_Vector3I	getGhostRes () const

int	getGhostRes (int dim) const

UT_Vector3I	getPadding () const

int	getPadding (int dim) const

int	getOffset () const

int	getGhostOffset () const

void	setBorder (UT_VoxelBorderType type, fpreal32 t)

UT_VoxelBorderType	getBorder () const

fpreal32	getBorderValue () const

void	setBorderScale (fpreal32 scalex, fpreal32 scaley, fpreal32 scalez)

fpreal32	getBorderScale (int axis) const

bool	indexToPos (int x, int y, int z, UT_Vector3F &pos) const

void	updateBorderCells () const

int64	numVoxels () const
	Returns the number of data voxels in the grid. More...

int64	numTotalVoxels () const

int64	totalVoxelMemory () const

void	initFromVoxels (const UT_VoxelArrayF &src, int xghost=1, int yghost=1, int zghost=1, int xpad=1, int ypad=1, int zpad=1)

void	matchAndCopyToVoxels (UT_VoxelArrayF &dest, bool include_ghost_cells=false) const

void	match (const CE_Grid &src)
	Match the src CE_Grid in terms of size and border conditions. More...

bool	isMatching (const CE_Grid &src) const

bool	isCongruent (const CE_Grid &src) const
	Returns true if this CE_Grid matches src in terms of offset and strides. More...

int	getXStride () const

int	getYStride () const

int	getZStride () const

int	getStride (int dim) const

UT_Vector3I	getStrides () const

int	getGhostStride (int axis) const
	Returns the stride along axis including ghost cells. More...

bool	isAxis2D (int axis) const
	Returns whether the specified axis is 2-dimensional. More...

int	getAxis2D () const
	Returns the 2-dimensional axis of this grid, or -1 if there is none. More...

int	getXStride2D (int axis2d) const
	2D strides. More...

int	getYStride2D (int axis2d) const

int	getXStride2D3D () const

int	getYStride2D3D () const

int	getZStride2D3D () const
	Returns the true Z-stride if the grid is 3D, or 0 if 2D. More...

int	getXRes2D3D () const

int	getYRes2D3D () const

int	getZRes2D3D () const
	Returns the true z resolution if the grid is 3D, or 1 if 2D. More...

void	constant (fpreal32 v)

void	zero ()

bool	isConstant (fpreal32 *cval=0, bool check_borders=false) const

void	copyData (const CE_Grid &src)

CE_Grid &	operator= (const CE_Grid &src)
	Assign to this, equivalent to match(src), followed by copyData(src). More...

void	stealBuffer (CE_Grid &src)
	Steal the buffer from the other grid, leaving it unitialized. More...

CE_Grid &	operator+= (const CE_Grid &src)

cl::NDRange	getGlobalRange () const

cl::NDRange	getGlobalRange2D (int axis2d) const

cl::NDRange	getGlobalRange2D3D () const

cl::NDRange	getLocalRange2D3D () const

cl::KernelFunctor	bind (cl::Kernel k, const cl::NDRange *lrange=nullptr, int n=1) const

cl::KernelFunctor	bind (cl::Program prog, const char *kernelname) const

cl::KernelFunctor	bind2D (int axis, cl::Kernel k) const

cl::KernelFunctor	bind2D (int axis, cl::Program prog, const char *kernelname) const

cl::KernelFunctor	bind2D3D (cl::Kernel k) const

cl::KernelFunctor	bind2D3D (cl::Program prog, const char *kernelname) const

void	scaledAddCornerFromCenter (fpreal32 c1, const CE_Grid &g1)

void	linearCombination (fpreal32 c0, const CE_Grid &g0, fpreal32 d)

void	linearCombination (fpreal32 c0, const CE_Grid &g0, fpreal32 c1, const CE_Grid &g1, fpreal32 d)

void	linearCombination (fpreal32 c0, const CE_Grid &g0, fpreal32 c1, const CE_Grid &g1, fpreal32 c2, const CE_Grid &g2, fpreal32 d)

void	divergence (const CE_Grid &x, const CE_Grid &y, const CE_Grid &z, fpreal32 scale, UT_Vector3 voxel_size)

void	divergenceCenterToCorner (const CE_Grid &x, const CE_Grid &y, const CE_Grid &z, fpreal32 scale, UT_Vector3 voxel_size)

void	applyGradient (const CE_Grid &p, fpreal32 scale, fpreal32 voxel_size, int axis)

void	applyGradientCornerToCenter (const CE_Grid &p, fpreal32 scale, fpreal32 voxelsize, int axis)

fpreal64	sum () const
	Reductions of the grid to a single value. More...

fpreal64	sumAbs () const

fpreal64	sumSqr () const

fpreal64	min () const

fpreal64	minAbs () const

fpreal64	max () const

fpreal64	maxAbs () const

fpreal64	average () const

fpreal64	localAverage (UT_Vector3I &radius)

fpreal64	localSum (UT_Vector3I &radius)

fpreal64	localSumSqr (UT_Vector3I &radius)

fpreal64	localSumAbs (UT_Vector3I &radius)

fpreal64	localMin (UT_Vector3I &radius)

fpreal64	localMinAbs (UT_Vector3I &radius)

fpreal64	localMax (UT_Vector3I &radius)

fpreal64	localMaxAbs (UT_Vector3I &radius)

void	boxBlur (int passes, UT_Vector3 radius)

void	computeNorms (fpreal64 &norminf, fpreal64 &norm2) const
	Compute the infinity-norm and 2-norm of the grid. More...

Additional Inherited Members
Static Public Member Functions inherited from CE_Grid
static int	getXAxis2D (int axis2d)

static int	getYAxis2D (int axis2d)

static cl::NDRange	getLocalRange (const cl::NDRange &g)
	Create a local work item range for the supplied global range. More...

Protected Member Functions inherited from CE_Grid
const cl::Buffer &	allocBuffer () const

void	releaseBuffer ()

void	setValue (fpreal32 cval) const

void	getReductionRanges (const cl::Kernel &k, cl::NDRange &globalRange, cl::NDRange &localRange, uint &groupsize, uint &ngroups, size_t &accumsize) const

fpreal64	reduceFlat (cl::Buffer outgrid, uint groupsize, uint ngroups, size_t accumsize, const char *reduce_flags) const

fpreal64	doReduce (const char *reduce_flags) const

bool	doLocalReduce (const char *options, UT_Vector3I &radius)

Protected Attributes inherited from CE_Grid
cl::Buffer	myBuffer

bool	myIsConstant

fpreal32	myConstantVal

UT_Vector3I	myRes

UT_Vector3I	myGhostCells

UT_Vector3I	myPadding

int	myAxis2d

UT_Vector3I	myStrides

fpreal32	myBorderValue

UT_VoxelBorderType	myBorderType

UT_Vector3F	myBorderScale

Detailed Description

This class provides a specializaion of CE_Grid that can solve the 2D or 3D Poisson equation using the multigrid algorithm, running on an OpenCL device. It's interface closely matches that of UT_MultigridArray.

Definition at line 21 of file CE_Multigrid.h.

Constructor & Destructor Documentation

CE_Multigrid::CE_Multigrid ( )

CE_Multigrid::~CE_Multigrid ( )

override

CE_Multigrid::CE_Multigrid ( const CE_Multigrid & )

default

Member Function Documentation

UT_Vector3I CE_Multigrid::coarsen	(	int	min_per_axis,
		CE_Multigrid &	uh
	)		const

Coarsen this grid into a lower resolution version of the grid.

void CE_Multigrid::coarsenAlongAxis	(	CE_Multigrid &	uh,
		int	axis
	)		const

Performs coarsening using full-weighting along one axis. On output

uh.getReas(axis) == getRes(axis) / 2

void CE_Multigrid::computeResidualNorms	(	const CE_Multigrid &	x,
		fpreal64 &	norminf,
		fpreal64 &	norm2
	)		const

Computes the inf and 2-norm of the residual r = b - A * x, where b == *this.

void CE_Multigrid::directSolve ( CE_Multigrid & x ) const

Directly solve the Poisson equation that this grid represents. This function should only be called for small grids. At the moment this always calls smoothLaplacianGaussSeidelSmall() with a large number of iterations.

void CE_Multigrid::fullMultigrid	(	int	min_per_axis,
		int	n_smooth_down,
		int	n_smooth_up,
		CE_Multigrid &	x
	)		const

Performs recursive Full Multigrid to generate an initial guess for the solution of the Poisson equation represented by this array. At each level, n_smooth_down and n_smooth_up iterations of smoothing are done.

int CE_Multigrid::getLevel ( ) const

inline

Returns a grid's level within the multigrid hierarchy.

Definition at line 62 of file CE_Multigrid.h.

int CE_Multigrid::getMaxCoarse ( int min_per_axis ) const

Calculates the maximum coarse grid elements in the coarsest grid, based on the min_per_axis parameter.

UT_Vector3I CE_Multigrid::getParity ( ) const

inline

Returns a vector containing the odd/even parity for each axis.

Definition at line 65 of file CE_Multigrid.h.

void CE_Multigrid::init	(	const UT_Vector3I &	res,
		const UT_Vector3 &	spacing,
		const UT_Vector3I &	boundaries_neg,
		const UT_Vector3I &	boundaries_pos,
		int	level = `0`,
		UT_Vector3I	odd_coarsenings = `UT_Vector3I(0, 0, 0)`
	)

Initialize array to given size, spacing, and boundary conditions.

void CE_Multigrid::initFromVoxels	(	const UT_VoxelArrayF &	f,
		const UT_Vector3 &	spacing,
		const UT_Vector3I &	boundaries_neg,
		const UT_Vector3I &	boundaries_pos
	)

Initializes this grid from the provided UT_VoxelArray, assuming the provided grid spacing.

void CE_Multigrid::interpolate	(	const UT_Vector3I &	interpolate_axis,
		const UT_Vector3I &	parity,
		CE_Multigrid &	u
	)		const

Interpolate this grid into a fine version of the grid. coarsen_axis is a vector of booleans specifying which axes to interpolate Where interpolate_axis[axis] is true, ensure that

u[axis] = getRes(axis) * 2 + parity[axis]

void CE_Multigrid::interpolateAlongAxis	(	CE_Multigrid &	u,
		int	axis
	)		const

Interpolate this array into u using inverse of full-weighting along one axis. On output

u.getRes(axis) == getRes(axis) * 2 + parity[axis]

void CE_Multigrid::match ( const CE_Multigrid & src )

Initializes this to be the same dimensions, boundary conditions, etc, of the given grid.

CE_Multigrid& CE_Multigrid::operator= ( const CE_Multigrid & )

default

void CE_Multigrid::smoothLaplacianGaussSeidel	(	CE_Multigrid &	x,
		int	iterations = `1`,
		bool	use_small = `true`
	)		const

Performs red-black Gauss-Seidel smoothing, where b == *this, and the implicit matrix is the Laplacian operator. If use_small is true, this use callsmoothLaplacianGaussSeidelSmall() if possible.

bool CE_Multigrid::smoothLaplacianGaussSeidelSmall	(	CE_Multigrid &	x,
		int	iterations = `1`
	)		const

Performs red-black Gauss-Seidel smoothing, using a kernel that only works when the entire grid can fit in one workgroup on the OpenCL device. Returns false if the criteria to run are not met.

int CE_Multigrid::solvePoisson	(	fpreal64	abstol,
		fpreal64	reltol,
		int	miniter,
		int	maxiter,
		CE_Multigrid &	x,
		UT_ValArray< fpreal64 > *	resnorminf,
		UT_ValArray< fpreal64 > *	resnorm2,
		bool	finish_between_iters = `false`,
		bool	start_fmg = `true`
	)		const

Iteratively solve the Poisson equation, assuming *this is the right hand side. This function will do at least miniter iterations, then continue to iterate until the 2-norm of the residual has been reduced by reltol, the inf-norm of the residual is below abstol, or maxiters is reached. The optional resnorm0 and resnorm2 parameters will contain the 0- and 2-norms of the residuals for each iteration. If start_fmg is true, the first iteration will be full-multigrid; otherwise, only v-cycles are used.

void CE_Multigrid::subtractApplyLaplacian	(	CE_Multigrid &	x,
		CE_Multigrid &	r
	)		const

Computes rhe residual r = b - A * x, where b == *this.

void CE_Multigrid::updateBoundaryConditions ( bool struts = false ) const

Update the grid's ghost cells with values that enforce the boundary conditions at its particular level in the multigrid hierarchy. If struts is true, ghost cells that are outside two or more of the axes are also updated (like + in the following diagram, where * represent the ghost cells that are filled in regardless of the value of struts). +*************+

*
ACTUAL GRID *
* +*************+

void CE_Multigrid::vcycle	(	int	min_per_axis,
		int	n_smooth_down,
		int	n_smooth_up,
		CE_Multigrid &	x,
		bool	smooth_top_level_down = `true`
	)		const

Perform recursive V-cycle for multigrid algorithm, until reaching numElements() < maxcoarse, at which point a direct solve is done using directSolve.. At each level, n_smooth_down and n_smooth_up iterations of Gauss-Seidel smoothing are done, unless smooth_top_level_down is false, in which case no smoothing is done for the top-level grid on the down-cycle. This can be used as an optimization when calling vcycle iteratively; the previous vcycle call will have smoothed the top-level grid as its last step, so you can often skip smoothing that same grid on the next vcycle without loss of convergence.

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

CE/CE_Multigrid.h

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation