Solution Data

• Flow Solution
  • cg_sol_write - Create and/or write to a FlowSolution_t node
  • cg_nsols - Get number of FlowSolution_t nodes
  • cg_sol_info - Get info about a FlowSolution_t node
  • cg_sol_ptset_write - Create a point set FlowSolution_t node
  • cg_sol_ptset_info - Get info about a point set FlowSolution_t node
  • cg_sol_ptset_read - Read a point set FlowSolution_t node
  • cg_sol_size - Get the dimensions of a FlowSolution_t node
• Flow Solution Data
  • cg_field_write - Write flow solution
  • cg_field_partial_write - Write subset of flow solution
  • cg_field_general_write - Write shaped array to a subset of flow solution
  • cg_nfields - Get number of flow solution arrays
  • cg_field_info - Get info about a flow solution array
  • cg_field_read - Read flow solution
  • cg_field_general_read - Read subset of flow solution to a shaped array
• Discrete Data
  • cg_discrete_write - Create a DiscreteData_t node
  • cg_ndiscrete - Get number of DiscreteData_t nodes
  • cg_discrete_read - Get name of a DiscreteData_t node
  • cg_discrete_ptset_write - Create a point set DiscreteData_t node
  • cg_discrete_ptset_info - Get info about a point set DiscreteData_t node
  • cg_discrete_ptset_read - Read a point set DiscreteData_t node
  • cg_discrete_size - Get the dimensions of a DiscreteData_t node
• Zone Subregions
  • cg_nsubregs - Get number of ZoneSubRegion_t nodes
  • cg_subreg_info - Get info about a ZoneSubRegion_t node
  • cg_subreg_ptset_read - Read point set data for a ZoneSubRegion_t node
  • cg_subreg_bcname_read - Read the BC_t node name for a ZoneSubRegion_t node
  • cg_subreg_gcname_read - Read the GridConnectivity_t node name for a ZoneSubRegion_t node
  • cg_subreg_ptset_write - Create a point set ZoneSubRegion_t node
  • cg_subreg_bcname_write - Create a ZoneSubRegion_t node that references a BC_t node
  • cg_subreg_gcname_write - Create a ZoneSubRegion_t node that references a GridConnectivity_t node

Flow Solution

The above functions are used to create, and get information about, FlowSolution_t nodes.

Solution data may be specified over the entire zone, as in previous versions of the library, using cg_sol_write or over a patch region of the zone using cg_sol_ptset_write. The two are mutually exclusive. In the first case, the size of the solution data is determined by the size of the zone, the grid location, and rind data (if any) as in previous versions. In the second case the solution data size is entirely determined by the PointList/PointRange patch. In order to determine which of the two forms in which the solution data was written, use cg_sol_ptset_info. If the solution is over the entire zone, ptset_type will be returned as CG_Null and npnts as 0. Otherwise, ptset_type will be either PointList or PointRange, and the number of points will be returned in npnts.

To assist in determining the size of the solution data, the function cg_sol_size has been added. For a solution defined over the full zone, data_dim returns the index dimension for the zone, and dim_vals specifies the dimensions of the data, corrected for the grid location type and rind data. If a point set patch has been specified, data_dim will be 1 and dim_vals will contain the total size of the patch.

Acceptable values of GridLocation_t are Vertex and CellCenter. If the base cell dimension is 2 or greater (surface or volume), then EdgeCenter is also allowed. For 3 dimensional bases, FaceCenter, and for structured zones, IFaceCenter, JFaceCenter and KFaceCenter, are also acceptable.

Flow Solution Data

The above functions are used to read and write solution arrays stored below a FlowSolution_t node.

When writing, the function cg_field_write will automatically write the full range of the solution (i.e., the entire solution_array). The functions cg_field_partial_write and cg_field_general_write may be used to write only a subset of solution_array. When using the partial write, any existing data from range_min to range_max will be overwritten by the new values. All other values will not be affected.

The function cg_field_read returns the solution array fieldname, for the range prescribed by range_min and range_max. The array is returned to the application in the data type requested in mem_datatype. This data type does not need to be the same as the one in which the data is stored in the file. A solution array stored as double precision in the CGNS file can be returned to the application as single precision, or vice versa. The functions cg_field_general_read and cg_field_general_write allow for type conversion when both reading from and writing to the file.

In Fortran, when using cg_field_read_f to read a 2D or 3D solution, the extent of each dimension of solution_array must be consistent with the requested range. When reading a 1D solution, the declared size can be larger than the requested range. For example, for a 2D zone with 100 × 50 vertices, if range_min and range_max are set to (11,11) and (20,20) to read a subset of the solution, then solution_array must be dimensioned (10,10). If solution_array is declared larger (e.g., (100,50)) the indices for the returned array values will be wrong. These restrictions can be avoided by using cg_field_general_read_f instead.

When using cg_field_general_write and cg_field_general_read, the lower core locations in the file have index 1 for defining range_min and range_max; whereas for the array in memory, defined by mem_rank and mem_dimensions, the lower array locations in memory have index 1 for defining mem_range_min and mem_range_max. The actual lower and upper bounds of the array in memory can be anything. For example, to fully read a two-dimensional 6 × 6 solution array with 1 rind plane on each side in the file to an 8 × 8 array in memory (mem_rank = 2 and mem_dimensions = (8,8)), set range_min and range_max to (0,0) and (7,7), and set mem_range_min and mem_range_max to (1,1) and (8,8).

Discrete Data

DiscreteData_t nodes are intended for the storage of fields of data not usually identified as part of the flow solution, such as fluxes or equation residuals.

The description for these functions is similar to the FlowSolution_t node as described above. To read and write the discrete data, use cg_goto to access the DiscreteData_t node, then cg_array_read and cg_array_write. The dimensions provided to the array-write family of functions must match the dimensions specified by the Zone_t and DiscreteData_t nodes. Use cg_gridlocation_write and cg_rind_write under the DiscreteData_t node, as required.

Zone Subregions

These functions allow for the specification of Zone subregions. The subregion may be specified as either the name of an existing BC_t node (cg_subreg_bcname_write), an existing GridConnectivity_t or GridConnectivity1to1_t node (cg_subreg_gcname_write), or as a PointSet/PointRange (cg_subreg_ptset_write). These specifications are mutually exclusive. To determine the type of the subregion, use cg_subreg_info. If the subregion is a point set, then ptset_type will indicate the point set type (either PointList or PointRange) and npts will be set to the number of points to define the region. Otherwise, ptset_type will be set to CG_Null and npnts will be 0. In this case, one of bcname_len or gcname_len will be non-zero, indicating whether the ZoneSubRegion references a BC_t node (bcname_len non-zero) or GridConnectivity_t node (gcname_len non-zero).