Index

NAME

FieldWriter - storage of fields on files

INCLUDE

include "FieldWriter.h"

SYNTAX

 class FieldWriter
 {
 private:

   String name_of_dataset;

   // data output files
   Os fieldfile;
   Os gridfile;

   Format_type field_format;
   Format_type grid_format;

   // index files
   Os field_ixfile;
   Os grid_ixfile;

   // map file:
   Os simres_map;

   // provides information about existing dataset
   FieldReader reader;

   // files open/closed flag
   bool     files_open;
   FileMode next_openmode_ix,next_openmode_dat;


   void writeGridHeader
      (
       const Grid&  grid,
       const int    gridnum,
       const int    checknum
      );

   void updateGridIndex (const int  gridnum, const long address);

   void writeFieldHeader
      (
             Field&  field,
       const int  fieldnum,
       const int  gridnum,
       const String& header,
       const real time,
       const String& description,
       const int  component,
       const int  maxcomponent
      );

   void updateFieldIndex (const int fieldnum, const long address);

   void  open();          // opens output files
   void  close();         // closes output files

   // list of all datasets managed by all FieldWriter objects:
   static StringList dataset_names;
   bool datasetIsManaged (const String& dataset_name);
   void newDataset (const String& dataset_name);

 public:
   FieldWriter ();
   FieldWriter (const String& dataset_name,const bool append = false);
  ~FieldWriter();

   // it is possible to switch to another dataset:
   void setDatasetName (const String& dataset_name,
                        const bool append = false);

   void setStorageMode (Format_type field_format, Format_type grid_format);

   int writeField               // returns assigned field number in data set
      (
             Field&  field,
       const String& header,
       const real    time,
       const String& description,
       const int     component = 1,
       const int     maxcomponent = 1
      );

   int writeField               // version without description
      (
             Field&  field,
       const String& header,
       const real    time = DUMMY,
       const int     component = 1,
       const int     maxcomponent = 1
      );

   int writeField               // version without header or description
      (
             Field&  field,
       const real    time = DUMMY,
       const int     component = 1,
       const int     maxcomponent = 1
      );
 };

DESCRIPTION

This  class  is a low-level tool mainly used from classes SimRes­
File or SaveSimRes.

The storage format is binary or ASCII. In binary mode we  try  to
use the hardware-independent xdr format if possible (on some sys­
tems, problems might arise with xdr and then the FieldReader  and
FieldWriter  classes  can be compiled using a straight (binary) C
file - see the .cpp file for how you can steer the compilation in
case  there  are  problems  with  the  xdr  format  in Is_xdr and
Os_xdr.)

MEMBER FUNCTIONS

setDatasetName - Sets the name of the dataset. When a dataset  is
already  open,  it will be closed and the FieldWriter object will
connect to the new dataset instead. If the new dataset is already
existing, the append flag determines whether is will be overwrit­
ten or appended to.

setStorageMode - Sets the storage mode for the grids and  fields.

writeField  -  Stores  a specified field to the dataset. A header
and a time stamp must be specified. An optional  description  can
also  be given. The component number and the total number of com­
ponents (maxcomponent) must be specified when storing  components
of a vector field, otherwise the default values can be used.

EXAMPLES

See the information given in FieldReader.h.

SEE ALSO

Visualisering  av  skalar-  og  vektor-felt  by Fred Ivar Larsen,
1997.  (Thesis for the Cand.Scient. degree)

"Visualizing Scalar and Vector Fields  in  Diffpack  Hans  Petter
Langtangen / Fred Ivar Larsen

DEVELOPED BY

SINTEF Applied Mathematics, Oslo, Norway, and University of Oslo,
Dept. of Mathematics, Norway

AUTHOR

Fred Ivar Larsen, UiO