/**
* @brief function to check whether all initial parameters are set
* @param handle FCS-object representing an FCS solver
* @return whether all initial parameters are set
*/
static fcs_int fcs_init_check(FCS handle)
{
if (handle == FCS_NULL) return 0;
return (fcs_get_method(handle) != FCS_METHOD_NONE &&
fcs_get_communicator(handle) != MPI_COMM_NULL);
}
/* method to check if p3m parameters are entered into FCS */
static FCSResult fcs_p3m_check(FCS handle, const char* fnc_name) {
if (handle == NULL)
return fcs_result_create(FCS_ERROR_NULL_ARGUMENT, fnc_name, "null pointer supplied as handle");
if (fcs_get_method(handle) != FCS_METHOD_P3M)
return fcs_result_create(FCS_ERROR_WRONG_ARGUMENT, fnc_name, "Wrong method chosen. You should choose \"p3m\".");
return NULL;
}
/* method to check if mmm1d parameters are entered into FCS */
FCSResult fcs_mmm1d_check(FCS handle, const char* fnc_name) {
if (handle == NULL)
return fcsResult_create(FCS_NULL_ARGUMENT, fnc_name, "null pointer supplied as handle");
if (fcs_get_method(handle) != FCS_MMM1D)
return fcsResult_create(FCS_WRONG_ARGUMENT, fnc_name, "Wrong method chosen. You should choose \"mmm1d\".");
return NULL;
}
/**
* @brief 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.
*
* @param handle FCS-object that contains the parameter.
* @param discretization_order Discretization order.
*
* @return FCSResult-object containing the return value.
*/
extern FCSResult fcs_vmg_get_discretization_order(FCS handle, fcs_int* discretization_order)
{
char fnc_name[] = "fcs_vmg_get_discretization_order";
if (handle == NULL)
return fcsResult_create(FCS_NULL_ARGUMENT, fnc_name, "null pointer supplied as handle");
if (fcs_get_method(handle) != FCS_VMG)
return fcsResult_create(FCS_WRONG_ARGUMENT, fnc_name, "Wrong method chosen. You should choose \"vmg\".");
*discretization_order = handle->vmg_param->discretization_order;
return NULL;
}
/**
* @brief Get the number of near field cells for separating the
* near/far field part of the potential.
*
* @param handle FCS-object that contains the parameter.
* @param near_field_cells Number of near field cells.
*
* @return FCSResult-object containing the return value.
*/
extern FCSResult fcs_vmg_get_near_field_cells(FCS handle, fcs_int* near_field_cells)
{
char fnc_name[] = "fcs_vmg_get_near_field_cells";
if (handle == NULL)
return fcsResult_create(FCS_NULL_ARGUMENT, fnc_name, "null pointer supplied as handle");
if (fcs_get_method(handle) != FCS_VMG)
return fcsResult_create(FCS_WRONG_ARGUMENT, fnc_name, "Wrong method chosen. You should choose \"vmg\".");
*near_field_cells = handle->vmg_param->near_field_cells;
return NULL;
}
/**
* @brief 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.
*
* @param handle FCS-object that contains the parameter.
* @param cycle_type type of multigrid cycle.
*
* @return FCSResult-object containing the return value.
*/
extern FCSResult fcs_vmg_get_cycle_type(FCS handle, fcs_int* cycle_type)
{
char fnc_name[] = "fcs_vmg_get_cycle_type";
if (handle == NULL)
return fcsResult_create(FCS_NULL_ARGUMENT, fnc_name, "null pointer supplied as handle");
if (fcs_get_method(handle) != FCS_VMG)
return fcsResult_create(FCS_WRONG_ARGUMENT, fnc_name, "Wrong method chosen. You should choose \"vmg\".");
*cycle_type = handle->vmg_param->cycle_type;
return NULL;
}
/**
* @brief Get the precision of the vmg algorithm. Currently, the relative residual
* computed in the discrete L2 norm will be tested against this value.
*
* @param handle FCS-object that contains the parameter.
* @param precision Precision of the vmg algorithm.
*
* @return FCSResult-object containing the return value.
*/
extern FCSResult fcs_vmg_get_precision(FCS handle, fcs_float* precision)
{
char fnc_name[] = "fcs_vmg_get_precision";
if (handle == NULL)
return fcsResult_create(FCS_NULL_ARGUMENT, fnc_name, "null pointer supplied as handle");
if (fcs_get_method(handle) != FCS_VMG)
return fcsResult_create(FCS_WRONG_ARGUMENT, fnc_name, "Wrong method chosen. You should choose \"vmg\".");
*precision = handle->vmg_param->precision;
return NULL;
}
/**
* @brief Function to set all vmg parameters with a single call
*
* @param handle FCS-object that contains the parameters
* @param max_level The maximum level of the algorithm, i.e. n_gridpoints = 2^max_level.
* @param spline_degree The degree of the interpolating B-Splines.
* @param max_iterations The maximum number of multigrid iterations.
* @param smoothing_steps Number of pre/postsmoothing steps on each level.
* @param cycle_type Cycle-number.
* @param precision Desired precision.
* @param near_field_cells Number of near field cells.
* @param interpolation_order Interpolation order.
* @param discretization_order Discretization order.
*
* @return FCSResult-object containing the return value.
*/
extern 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)
{
FCSResult result;
char fnc_name[] = "fcs_vmg_setup";
if (handle == NULL)
return fcsResult_create(FCS_NULL_ARGUMENT, fnc_name, "null pointer supplied as handle");
if (fcs_get_method(handle) != FCS_VMG)
return fcsResult_create(FCS_WRONG_ARGUMENT, fnc_name, "Wrong method chosen. You should choose \"vmg\".");
result = fcs_vmg_set_max_level(handle, max_level);
if (result != NULL)
return result;
result = fcs_vmg_set_max_iterations(handle, max_iterations);
if (result != NULL)
return result;
result = fcs_vmg_set_smoothing_steps(handle, smoothing_steps);
if (result != NULL)
return result;
result = fcs_vmg_set_cycle_type(handle, cycle_type);
if (result != NULL)
return result;
result = fcs_vmg_set_precision(handle, precision);
if (result != NULL)
return result;
result = fcs_vmg_set_near_field_cells(handle, near_field_cells);
if (result != NULL)
return result;
result = fcs_vmg_set_interpolation_order(handle, interpolation_order);
if (result != NULL)
return result;
result = fcs_vmg_set_discretization_order(handle, discretization_order);
if (result != NULL)
return result;
return NULL;
}
/**
* @brief Set the interpolation order for interpolating
* the gridded potential to the particle positions.
*
* @param handle FCS-object that contains the parameter.
* @param interpolation order Interpolation order.
*
* @return FCSResult-object containing the return value.
*/
extern FCSResult fcs_vmg_set_interpolation_order(FCS handle, fcs_int interpolation_order)
{
char fnc_name[] = "fcs_vmg_set_interpolation_order";
if (handle == NULL)
return fcsResult_create(FCS_NULL_ARGUMENT, fnc_name, "null pointer supplied as handle");
if (fcs_get_method(handle) != FCS_VMG)
return fcsResult_create(FCS_WRONG_ARGUMENT, fnc_name, "Wrong method chosen. You should choose \"vmg\".");
if (interpolation_order < 3)
return fcsResult_create(FCS_WRONG_ARGUMENT, fnc_name, "Interpolation order must be greater or equal three.");
handle->vmg_param->interpolation_order = interpolation_order;
return NULL;
}
/**
* @brief Set the number of pre/postsmoothing steps on each level
*
* @param handle FCS-object that contains the parameter
* @param smoothing_steps Number of smoothing steps
*
* @return FCSResult-object containing the return state
*/
extern FCSResult fcs_vmg_set_smoothing_steps(FCS handle, fcs_int smoothing_steps)
{
char fnc_name[] = "fcs_vmg_set_smoothing_steps";
if (handle == NULL)
return fcsResult_create(FCS_NULL_ARGUMENT, fnc_name, "null pointer supplied as handle");
if (fcs_get_method(handle) != FCS_VMG)
return fcsResult_create(FCS_WRONG_ARGUMENT, fnc_name, "Wrong method chosen. You should choose \"vmg\".");
if (smoothing_steps < 1)
return fcsResult_create(FCS_WRONG_ARGUMENT, fnc_name, "The number of smoothing steps must be at least one.");
handle->vmg_param->smoothing_steps = smoothing_steps;
return NULL;
}
/**
* @brief Set the maximum number of multigrid iterations.
*
* @param handle FCS-object that contains the parameter
* @param max_iterations Number of iterations.
*
* @return FCSResult-object containing the return state.
*/
extern FCSResult fcs_vmg_set_max_iterations(FCS handle, fcs_int max_iterations)
{
char fnc_name[] = "fcs_vmg_set_max_iterations";
if (handle == NULL)
return fcsResult_create(FCS_NULL_ARGUMENT, fnc_name, "null pointer supplied as handle");
if (fcs_get_method(handle) != FCS_VMG)
return fcsResult_create(FCS_WRONG_ARGUMENT, fnc_name, "Wrong method chosen. You should choose \"vmg\".");
if (max_iterations < 1)
return fcsResult_create(FCS_WRONG_ARGUMENT, fnc_name, "The maximum number of iterations must be positive.");
handle->vmg_param->max_iterations = max_iterations;
return NULL;
}
/**
* @brief 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.
*
* @param handle FCS-object that contains the parameter
* @param max_level number of iterations
*
* @return FCSResult-object containing the return state
*/
extern FCSResult fcs_vmg_set_max_level(FCS handle, fcs_int max_level)
{
char fnc_name[] = "fcs_vmg_set_max_level";
if (handle == NULL)
return fcsResult_create(FCS_NULL_ARGUMENT, fnc_name, "null pointer supplied as handle");
if (fcs_get_method(handle) != FCS_VMG)
return fcsResult_create(FCS_WRONG_ARGUMENT, fnc_name, "Wrong method chosen. You should choose \"vmg\".");
if (max_level < 3)
return fcsResult_create(FCS_WRONG_ARGUMENT, fnc_name, "The finest level must be at least 3.");
handle->vmg_param->max_level = max_level;
return NULL;
}
/**
* return whether the solver method supports the delegation of near-field computations
*/
FCSResult fcs_get_near_field_delegation(FCS handle, fcs_int *near_field_delegation)
{
CHECK_HANDLE_RETURN_RESULT(handle, __func__);
*near_field_delegation = 0;
switch (fcs_get_method(handle))
{
#ifdef FCS_ENABLE_P2NFFT
case FCS_METHOD_P2NFFT:
*near_field_delegation = 1;
break;
#endif
#ifdef FCS_ENABLE_P3M
case FCS_METHOD_P3M:
*near_field_delegation = 1;
break;
#endif
}
return FCS_RESULT_SUCCESS;
}
/**
* compute the near-field component of the field
*/
FCSResult fcs_compute_near_field(FCS handle, fcs_float dist, fcs_float *field)
{
switch (fcs_get_method(handle))
{
#ifdef FCS_ENABLE_P2NFFT
case FCS_METHOD_P2NFFT:
*field = fcs_p2nfft_compute_near_field(handle, dist);
return FCS_RESULT_SUCCESS;
#endif
#ifdef FCS_ENABLE_P3M
case FCS_METHOD_P3M:
{
fcs_p3m_near_parameters_t params;
fcs_p3m_get_near_parameters(handle, ¶ms);
*field = fcs_p3m_compute_near_field(params, dist);
}
return FCS_RESULT_SUCCESS;
#endif
}
return fcs_result_create(FCS_ERROR_NOT_IMPLEMENTED, __func__, "Computing the near-field component of the field not implemented for solver method '%s'", fcs_get_method_name(handle));
}
/**
* compute the near-field component of the potential
*/
FCSResult fcs_compute_near_potential(FCS handle, fcs_float dist, fcs_float *potential)
{
const char *fnc_name = "fcs_compute_near_potential";
switch (fcs_get_method(handle))
{
#ifdef FCS_ENABLE_P2NFFT
case FCS_METHOD_P2NFFT:
*potential = fcs_p2nfft_compute_near_potential(handle, dist);
return FCS_RESULT_SUCCESS;
#endif
#ifdef FCS_ENABLE_P3M
case FCS_METHOD_P3M:
{
fcs_p3m_near_parameters_t params;
fcs_p3m_get_near_parameters(handle, ¶ms);
*potential = fcs_p3m_compute_near_potential(params, dist);
}
return FCS_RESULT_SUCCESS;
#endif
}
return fcs_result_create(FCS_ERROR_NOT_IMPLEMENTED, fnc_name, "Computing the near-field component of the potential not implemented for solver method '%s'", fcs_get_method_name(handle));
}
/**
* @brief function to set default values if no values are set
* @param handle the FCS-obect into which the default parameters will be entered
* @return FCSResult-object containing the return state
*/
extern FCSResult fcs_vmg_set_default(FCS handle)
{
MPI_Comm comm;
int rank;
const char fnc_name[] = "fcs_vmg_set_default";
comm = fcs_get_communicator(handle);
MPI_Comm_rank(comm, &rank);
if (handle == NULL)
return fcsResult_create(FCS_NULL_ARGUMENT, fnc_name, "null pointer supplied as handle");
if (fcs_get_method(handle) != FCS_VMG)
return fcsResult_create(FCS_WRONG_ARGUMENT, fnc_name, "Wrong method chosen. You should choose \"vmg\".");
fcs_int max_level;
fcs_vmg_get_max_level(handle, &max_level);
if (max_level < 0) {
max_level = 6;
#ifdef FCS_ENABLE_DEBUG
if (rank == 0)
printf("%s: Parameter %s not set. Set default to %d.\n", fnc_name, "max_level", max_level);
#endif
fcs_vmg_set_max_level(handle, max_level);
}
fcs_int max_iter;
fcs_vmg_get_max_iterations(handle, &max_iter);
if (max_iter < 0) {
max_iter = 15;
#ifdef FCS_ENABLE_DEBUG
if (rank == 0)
printf("%s: Parameter %s not set. Set default to %d.\n", fnc_name, "max_iterations", max_iter);
#endif
fcs_vmg_set_max_iterations(handle, max_iter);
}
fcs_int smoothing_steps;
fcs_vmg_get_smoothing_steps(handle, &smoothing_steps);
if (smoothing_steps < 0) {
smoothing_steps = 3;
#ifdef FCS_ENABLE_DEBUG
if (rank == 0)
printf("%s: Parameter %s not set. Set default to %d.\n", fnc_name, "smoothing_steps", smoothing_steps);
#endif
fcs_vmg_set_smoothing_steps(handle, smoothing_steps);
}
fcs_int cycle_type;
fcs_vmg_get_cycle_type(handle, &cycle_type);
if (cycle_type < 0) {
cycle_type = 1;
#ifdef FCS_ENABLE_DEBUG
if (rank == 0)
printf("%s: Parameter %s not set. Set default to %d.\n", fnc_name, "cycle_type", cycle_type);
#endif
fcs_vmg_set_cycle_type(handle, cycle_type);
}
fcs_float precision;
fcs_vmg_get_precision(handle, &precision);
if (precision < 0.0) {
precision = 1.0e-8;
#ifdef FCS_ENABLE_DEBUG
if (rank == 0)
printf("%s: Parameter %s not set. Set default to %e.\n", fnc_name, "precision", precision);
#endif
fcs_vmg_set_precision(handle, precision);
}
fcs_int near_field_cells;
fcs_vmg_get_near_field_cells(handle, &near_field_cells);
if (near_field_cells < 0) {
near_field_cells = 4;
#ifdef FCS_ENABLE_DEBUG
if (rank == 0)
printf("%s: Parameter %s not set. Set default to %d.\n", fnc_name, "near_field_cells", near_field_cells);
#endif
fcs_vmg_set_near_field_cells(handle, near_field_cells);
}
fcs_int interpolation_order;
fcs_vmg_get_interpolation_order(handle, &interpolation_order);
if (interpolation_order < 0) {
interpolation_order = 5;
#ifdef FCS_ENABLE_DEBUG
if (rank == 0)
printf("%s: Parameter %s not set. Set default to %d.\n", fnc_name, "interpolation_order", interpolation_order);
#endif
fcs_vmg_set_interpolation_order(handle, interpolation_order);
}
fcs_int discretization_order;
fcs_vmg_get_discretization_order(handle, &discretization_order);
if (discretization_order < 0) {
discretization_order = 4;
#ifdef FCS_ENABLE_DEBUG
if (rank == 0)
printf("%s: Parameter %s not set. Set default to %d.\n", fnc_name, "discretization_order", discretization_order);
#endif
fcs_vmg_set_discretization_order(handle, discretization_order);
}
return NULL;
}
