NCAGGREGATE

Basic Information

Name of Program

NCAGGREGATE

Version-Date

July 2022

Description-Date

September 2022

Catchwords

data analysis
postprocessor
synoptic data sets
tidal characteristic numbers
tide-independent characteristic numbers
differences for synoptic data sets
differences for tidal characteristic numbers
differences for tide-independent characteristic numbers
CF NetCDF format for 2D/3D data
aggregated data for control volumes and exchanges
orthogonal unstructured grid model
support of computational results based on sub-grid bathymetry
parallelization using OpenMP
support of DMQS metadata and variables
automatic quality assurance (value range)
automatic adjustment of number of data READ to chunk size of input data
automatic computation of chunk sizes for result variables to support orthogonal data access
Storage of the content of the ASCII input control files in netcdf.nc (as a variable)
Storage of MD5 hash values ​​of input files in netcdf.nc (as a variable)
optional use of Message Passing Interface (MPI, MPI Forum)

Acknowledgment: This project took advantage of netCDF software developed by UCAR/Unidata (www.unidata.ucar.edu/software/netcdf/).

Short Description of Functionality

Program NCAGGRGATE may be useful in different situations which are listed in the following. For each type of application a list of programs (with sequence of execution) is given:

• aggregation of synoptic transport data for control volumes aiming at a precise balance of transports (water volume, salt, etc.):
  Attention: To get an input file suitable for INSPECT_CONTROL_VOLUMES, the simulation must be performed at least with salt or temperature. Even if you are only interested in the hydrodynamics, NCAGGREGATE also has to aggregate the salt or temperature values. The aggregated synoptic water volume is otherwise not calculated. However, this physical quantity is required for the calculations performed in INSPECT_CONTROL_VOLUMES.
  1. UNTRIM2007 or UNTRIM2,
  2. NCAGGREGATE,
  3. INSPECT_CONTROL_VOLUMES (check results),
  4. NCANALYSE, and
  5. DISPLAY_CONTROL_VOLUMES.
• aggregation of synoptic data (water level, current velocity, salinity, etc.) aiming at the reduction of data complexity:
  1. UNTRIM2007 or UNTRIM2,
  2. NCAGGREGATE, and
  3. NCPLOT.
• aggregation of characteristic numbers aiming at the reduction of data complexity:
  1. UNTRIM2007 or UNTRIM2,
  2. NCANALYSE,
  3. NCPLOT (check characteristic numbers),
  4. NCAGGREGATE, and
  5. NCPLOT.
• aggregation of differences for characteristic numbers or synoptic data aiming at the reduction of data complexity:
  1. UNTRIM2007 or UNTRIM2 (experimentally also for DFlow FM),
  2. NCANALYSE (computation of characteristic numbers),
  3. NCPLOT (check characteristic numbers),
  4. NCDELTA,
  5. NCPLOT (check differences),
  6. NCAGGREGATE, and
  7. NCPLOT.

During aggragation of classical data land binary masks (LBM) are automatically added to the result file. LBMs are used to describe the distribution of land and water at aggregation time. LBMs therefore empower visualization programs like NCPLOT to optimally present aggregated data in combination with a meaningful land-water-distribution.

Optionally the user is able to generate percentiles (0.01, 0.05, 0.50, 0.95 and 0.99) as well as probability distributions in addition to those aggregated data which are usually created. For further advice see ncaggregate.dat.

Picture control volumes and exchanges.

Input-Files

1. general input data (file type ncaggregate.dat);
2. file with classifications for probability distributions (file type bounds.cfg.dat)
   Hint: (Recommended) Local configuration file or file from the directory $PROGHOME/cfg/.
3. synoptic data sets (file type cf-netcdf.nc);
4. control volumes (file type ipds.dat);
5. for automatic quality assurance (file type bounds_verify.dat).

Output-Files

1. data analysis result files (file type cf-netcdf.nc); see NetCDF aggregation for unstructured grids for details about the aggregational grid.
2. (optional) informative printer file of program execution (file type ncaggregate.sdr)
3. (optional) trace of program execution (file type ncaggregate.trc)

Methodology

Physical data, suitable for aggregation, are collected for different control volumes as well as exchanges between adjacent control volumes.

Just in case HDF error is detected during read of a data record, the program tries to reconstruct the wanted data set from adjacent (in time) records for the same variable. This type of repair works for time dependent variables only.

Program(s) to run before this Program

NCANALYSE, NCCHUNKIE, NCCUTOUT, NCDELTA, NCDVAR, NCMERGE, UNTRIM2007, UNTRIM2, INSEL2IPDS

Program(s) to run after this Program

DAVIT, INSPECT_CONTROL_VOLUMES, NCANALYSE, NCAUTO, NCCHUNKIE, NCDELTA, NCDVAR, NCMERGE, NCPLOT, NC2TABLE, PLOTPROFILZEIT

Additional Information

Language

Fortran95

Additional software

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Original Version

G. Lang

Maintenance

Working group POS

Documentation/Literature

• Presentations (available in German only):
  • 2014-03-12: Aggregation von Daten.
• IZW-Campus (Podcast, available in German only)
  • 2020-12-07: Aggregation und NCAGGREGATE.
• Template Files:
  • template files available in $PROGHOME/examples/ncaggregate

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