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Basic Information




April 2020


April 2020

Significance of the File

contains general steering data for the program NCDVAR.

File-Contents (in Catchwords)

steering data

  • Block Program_Parameters: Allgemeine Steuerdaten
    1. Max_Read_Storage: Maximum number of data values ​​that can be read for each input variable in a copy cycle. Default = 125000000.
    2. (optional) Create_Missing_Variables: Generate additional variables
      • 0 = do not create additional variables (default)
      • 1 = generate additional variables (in combination with DFlow FM)
    3. (optional) NC_Deflate_Level: Compression of the result data
      • 0 = no compression
      • 1 ... 8 = compression (default = 3)
      • 9 = maximum compression
    4. (optional) END_After_Define: Abort after generating the metadata of the output file
      • .false. = Program runs through to the end (default)
      • .true. = Program ends after definition of the result file (metadata)
    5. (optional) Delete_Coordinate_Variables: Delete coordinate variables of a certain type
      • X-Y = all x and y coordinate variables (projected coordinates) are not transferred
      • LON-LAT = all lon and lat coordinates (geographic coordinates) are not transferred
      • If this key is not specified, all coordinate variables are transferred
  • Block Input_File: Input-Datei
    1. Data_File: Name and type of the input file (file of type
- File must exist
  • Block Output_File: Output-Datei
    1. Data_File Name and type of the output file (file of type
- File cannot exist
  • (optional) Block Mesh_Variables_Action: Actions on all variables of a grid (mesh)
    1. Action Name of the mesh variable and action (COPY, DELETE) to be carried out on the variables of this grid
- Not all files have mesh variables;
- If ALL is specified for Mesh, all variables are set to the corresponding action;
- The line may be specified more than once.
  • (optional) Block Single_Variable_Action: Actions for individual variables
    1. Action: Name of the variable and action (COPY, DELETE) to be carried out for this variable.
- Line may be specified more than once;
- Overrides the global action in Block Mesh_Variables_Action;
- The user may only list variables that he can influence. These are also known as geophysical variables. Coordinate variables, measure variables, etc. must not be specified by the user.
  • (optional) Block Time_Coordinate_Thinning: Thinning out of equidistant time coordinates
    1. Time_KV_Name: Name of a time coordinate variable
    2. Start_Time: Start time and time zone in format DD.MM.YYYY-hh:mm:ss.nnnnnnnnn zone
    3. End_Time: End time and time zone in format DD.MM.YYYY-hh:mm:ss.nnnnnnnnn zone
    4. Time_Step: Time step in format dddddd-hh:mm:ss.nnnnnnnnn
- Only works for temporally equidistant input data;
- The start and end times must be present in the input data;
- The time step must be an integer multiple of the input data.

General Remarks

  1. Used dictionary files from directory $PROGHOME/dic/:
    • ncdvar_dico.dat.
  2. Applications:
    • Case 1: deleting coordinate variables of a certain type;
    • Case 2: deleting/copying variables present on a certain grid;
    • Case 3: deleting/copying selected variables;
    • Case 4: deleting/copying selected dates in the time direction of equidistant data.

Programs using this Type of File


Additional Information













Original Version

G. Lang


G. Lang, S. Spohr



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