file containing all vmg specific functions More...

#include "fcs_definitions.h"
#include "fcs_result_p.h"
#include "fcs_interface_p.h"

Include dependency graph for fcs_vmg_p.h:

Typedefs
typedef struct fcs_vmg_parameters_t *	fcs_vmg_parameters

Functions
FCSResult	fcs_vmg_setup (FCS handle, fcs_int max_level, fcs_int max_iterations, fcs_int smoothing_steps, fcs_int cycle_type, fcs_float precision, fcs_int near_field_cells, fcs_int interpolation_order, fcs_int discretization_order)
	Function to set all vmg parameters with a single call. More...

FCSResult	fcs_vmg_set_max_level (FCS handle, fcs_int max_level)
	Set the maximum level of the multigrid algorithm. More...

FCSResult	fcs_vmg_get_max_level (FCS handle, fcs_int *max_level)
	Get the maximum level of the multigrid algorithm. More...

FCSResult	fcs_vmg_set_max_iterations (FCS handle, fcs_int max_iterations)
	Set the maximum number of multigrid iterations. More...

FCSResult	fcs_vmg_get_max_iterations (FCS handle, fcs_int *max_iterations)
	Get the maximum number of multigrid iterations. More...

FCSResult	fcs_vmg_set_smoothing_steps (FCS handle, fcs_int smoothing_steps)
	Set the number of pre/postsmoothing steps on each level. More...

FCSResult	fcs_vmg_get_smoothing_steps (FCS handle, fcs_int *smoothing_steps)
	Get the number of pre/postsmoothing steps on each level. More...

FCSResult	fcs_vmg_set_cycle_type (FCS handle, fcs_int cycle_type)
	Set the cycle_type-number of the multigrid cycle used. More...

FCSResult	fcs_vmg_get_cycle_type (FCS handle, fcs_int *cycle_type)
	Get the cycle_type-number of the multigrid cycle used. More...

FCSResult	fcs_vmg_set_precision (FCS handle, fcs_float precision)
	Set the precision of the vmg algorithm. More...

FCSResult	fcs_vmg_get_precision (FCS handle, fcs_float *precision)
	Get the precision of the vmg algorithm. More...

FCSResult	fcs_vmg_set_near_field_cells (FCS handle, fcs_int near_field_cells)
	Set the number of near field cells for separating the near/far field part of the potential. More...

FCSResult	fcs_vmg_get_near_field_cells (FCS handle, fcs_int *near_field_cells)
	Get the number of near field cells for separating the near/far field part of the potential. More...

FCSResult	fcs_vmg_set_interpolation_order (FCS handle, fcs_int interpolation_order)
	Set the interpolation order for interpolating the gridded potential to the particle positions. More...

FCSResult	fcs_vmg_get_interpolation_order (FCS handle, fcs_int *interpolation_order)
	Get the interpolation order for interpolating the gridded potential to the particle positions. More...

FCSResult	fcs_vmg_set_discretization_order (FCS handle, fcs_int discretization_order)
	Set the discretization order. More...

FCSResult	fcs_vmg_get_discretization_order (FCS handle, fcs_int *discretization_order)
	Get the discretization order. More...

void	vmg_fcs_print_timer ()
	Print runtimes of various vmg subsystems. More...

Detailed Description

file containing all vmg specific functions

Author: Rene Halver

Definition in file fcs_vmg_p.h.

Typedef Documentation

◆ fcs_vmg_parameters

typedef struct fcs_vmg_parameters_t* fcs_vmg_parameters

Definition at line 35 of file fcs_vmg_p.h.

Function Documentation

◆ fcs_vmg_get_cycle_type()

FCSResult fcs_vmg_get_cycle_type	(	FCS	handle,
		fcs_int *	cycle_type
	)

Get the cycle_type-number of the multigrid cycle used.

E.g. 1 corresponds to a V-Cycle and 2 corresponds to a W-Cycle.

Parameters

handle	FCS-object that contains the parameter.
cycle_type	type of multigrid cycle.

Returns: FCSResult-object containing the return value.

◆ fcs_vmg_get_discretization_order()

FCSResult fcs_vmg_get_discretization_order	(	FCS	handle,
		fcs_int *	discretization_order
	)

Get the discretization order.

This will affect the discretization error heavily, but a higher value also implies more computation. Possible values are 2 or 4.

Parameters

handle	FCS-object that contains the parameter.
discretization_order	Discretization order.

Returns: FCSResult-object containing the return value.

◆ fcs_vmg_get_interpolation_order()

FCSResult fcs_vmg_get_interpolation_order	(	FCS	handle,
		fcs_int *	interpolation_order
	)

Get the interpolation order for interpolating the gridded potential to the particle positions.

Parameters

handle	FCS-object that contains the parameter.
interpolation_order	Interpolation order.

Returns: FCSResult-object containing the return value.

◆ fcs_vmg_get_max_iterations()

FCSResult fcs_vmg_get_max_iterations	(	FCS	handle,
		fcs_int *	max_iterations
	)

Get the maximum number of multigrid iterations.

Parameters

handle	FCS-object that contains the parameter.
max_iterations	Number of iterations.

Returns: FCSResult-object containing the return state

◆ fcs_vmg_get_max_level()

FCSResult fcs_vmg_get_max_level	(	FCS	handle,
		fcs_int *	max_level
	)

Get the maximum level of the multigrid algorithm.

The number of grid points of the finest multigrid level will be 2^max_level.

Parameters

handle	FCS-object that contains the parameter
max_level	Number of iterations on return

Returns: FCSResult-object containing the return state

◆ fcs_vmg_get_near_field_cells()

FCSResult fcs_vmg_get_near_field_cells	(	FCS	handle,
		fcs_int *	near_field_cells
	)

Get the number of near field cells for separating the near/far field part of the potential.

Parameters

handle	FCS-object that contains the parameter.
near_field_cells	Number of near field cells.

Returns: FCSResult-object containing the return value.

◆ fcs_vmg_get_precision()

FCSResult fcs_vmg_get_precision	(	FCS	handle,
		fcs_float *	precision
	)

Get the precision of the vmg algorithm.

Currently, the relative residual computed in the discrete L2 norm will be tested against this value.

Parameters

handle	FCS-object that contains the parameter.
precision	Precision of the vmg algorithm.

Returns: FCSResult-object containing the return value.

◆ fcs_vmg_get_smoothing_steps()

FCSResult fcs_vmg_get_smoothing_steps	(	FCS	handle,
		fcs_int *	smoothing_steps
	)

Get the number of pre/postsmoothing steps on each level.

Parameters

handle	FCS-object that contains the parameter
smoothing_steps	Number of pre/postsmoothing steps

Returns: FCSReturn-object containing the return state.

◆ fcs_vmg_set_cycle_type()

FCSResult fcs_vmg_set_cycle_type	(	FCS	handle,
		fcs_int	cycle_type
	)

Set the cycle_type-number of the multigrid cycle used.

E.g. 1 corresponds to a V-Cycle and 2 corresponds to a W-Cycle.

Parameters

handle	FCS-object that contains the parameter.
cycle_type	Gamma.

Returns: FCSReturn-object containing the return state.

◆ fcs_vmg_set_discretization_order()

FCSResult fcs_vmg_set_discretization_order	(	FCS	handle,
		fcs_int	discretization_order
	)

Set the discretization order.

This will affect the discretization error heavily, but a higher value also implies more computation. Possible values are 2 or 4.

Parameters

handle	FCS-object that contains the parameter.
discretization_order	Discretization order.

Returns: FCSResult-object containing the return value.

◆ fcs_vmg_set_interpolation_order()

FCSResult fcs_vmg_set_interpolation_order	(	FCS	handle,
		fcs_int	interpolation_order
	)

Set the interpolation order for interpolating the gridded potential to the particle positions.

Parameters

handle	FCS-object that contains the parameter.
interpolation_order	Interpolation order.

Returns: FCSResult-object containing the return value.

◆ fcs_vmg_set_max_iterations()

FCSResult fcs_vmg_set_max_iterations	(	FCS	handle,
		fcs_int	max_iterations
	)

Set the maximum number of multigrid iterations.

Parameters

handle	FCS-object that contains the parameter
max_iterations	Number of iterations.

Returns: FCSResult-object containing the return state.

◆ fcs_vmg_set_max_level()

FCSResult fcs_vmg_set_max_level	(	FCS	handle,
		fcs_int	max_level
	)

Set the maximum level of the multigrid algorithm.

This sets the number of grid points to 2^max_level, so basically this parameter ensures that the number of grid points will be a power of two.

Parameters

handle	FCS-object that contains the parameter
max_level	number of iterations

Returns: FCSResult-object containing the return state

◆ fcs_vmg_set_near_field_cells()

FCSResult fcs_vmg_set_near_field_cells	(	FCS	handle,
		fcs_int	near_field_cells
	)

Set the number of near field cells for separating the near/far field part of the potential.

Parameters

handle	FCS-object that contains the parameter.
near_field_cells	Near field cells.

Returns: FCSResult-object containing the return value.

◆ fcs_vmg_set_precision()

FCSResult fcs_vmg_set_precision	(	FCS	handle,
		fcs_float	precision
	)

Set the precision of the vmg algorithm.

Currently, the relative residual computed in the discrete L2 norm will be tested against this value.

Parameters

handle	FCS-object that contains the parameter.
precision	Precision.

Returns: FCSResult-object containing the return value.

◆ fcs_vmg_set_smoothing_steps()

FCSResult fcs_vmg_set_smoothing_steps	(	FCS	handle,
		fcs_int	smoothing_steps
	)

Set the number of pre/postsmoothing steps on each level.

Parameters

handle	FCS-object that contains the parameter
smoothing_steps	Number of smoothing steps

Returns: FCSResult-object containing the return state

◆ fcs_vmg_setup()

FCSResult fcs_vmg_setup	(	FCS	handle,
		fcs_int	max_level,
		fcs_int	max_iterations,
		fcs_int	smoothing_steps,
		fcs_int	cycle_type,
		fcs_float	precision,
		fcs_int	near_field_cells,
		fcs_int	interpolation_order,
		fcs_int	discretization_order
	)

Function to set all vmg parameters with a single call.

Parameters

handle	FCS-object that contains the parameters
max_level	The maximum level of the algorithm, i.e. n_gridpoints = 2^max_level.
max_iterations	The maximum number of multigrid iterations.
smoothing_steps	Number of pre/postsmoothing steps on each level.
cycle_type	Cycle-number.
precision	Desired precision.
near_field_cells	Number of near field cells.
interpolation_order	Interpolation order.
discretization_order	Discretization order.

Returns: FCSResult-object containing the return value.

◆ vmg_fcs_print_timer()

void vmg_fcs_print_timer ( )

Print runtimes of various vmg subsystems.

vmg has to be configured with –enable-debug-measure-time in order to do so.

Typedefs

Functions

Detailed Description

Typedef Documentation

◆ fcs_vmg_parameters

Function Documentation

◆ fcs_vmg_get_cycle_type()

◆ fcs_vmg_get_discretization_order()

◆ fcs_vmg_get_interpolation_order()

◆ fcs_vmg_get_max_iterations()

◆ fcs_vmg_get_max_level()

◆ fcs_vmg_get_near_field_cells()

◆ fcs_vmg_get_precision()

◆ fcs_vmg_get_smoothing_steps()

◆ fcs_vmg_set_cycle_type()

◆ fcs_vmg_set_discretization_order()

◆ fcs_vmg_set_interpolation_order()

◆ fcs_vmg_set_max_iterations()

◆ fcs_vmg_set_max_level()

◆ fcs_vmg_set_near_field_cells()

◆ fcs_vmg_set_precision()

◆ fcs_vmg_set_smoothing_steps()

◆ fcs_vmg_setup()

◆ vmg_fcs_print_timer()