Output

Output

MODE Tool: Output

The output of MODE typically consists of 4 files: 2 ASCII statistics files, 1 NetCDF object file, and 1 PostScript summary plot. The output of any of these files may be disabled using the appropriate MODE command line argument. In this example, the output is written to the current mode directory, as we requested on the command line.

The MODE output file naming convention is similar to that of the other MET tools. It contains timing information about the forecast being evaluated (forecast valid, lead, and accumulation times).

If MODE is rerun on the same fields but with a slightly different configuration, the new output will override the old output, unless it is redirected to a different directory using the -outdir command line argument. Users can also edit the output_prefix in the MODE configuration file to customize the output file names.

The 4 MODE output files are described briefly below:

  • The PostScript file ends in .ps and is described below.
  • The NetCDF object file ends in _obj.nc and contains the object indices.
  • The ASCII contingency table statistics file and ends in _cts.txt.
  • The ASCII object statistics file ends in _obj.txt and contains all of the object and object comparison data.
You can use ghostview (gv) to look at the postscript file output from each of these three forecasts.
gv mode_240000L_20050808_000000V_240000A.ps &
If ghostview is not available, use display to view the files.  Click on the image to get a command box, then use File -> Next to move to the next page of the image.

 

There are multiple pages of output. Take a moment to look them over:

 

  1. Page 1 summarizes the entire MODE run. Thumbnail images show the input data, resolved objects, and numbers identifying each object for both the forecast and observation fields. The color indicates object matching between the forecast and observation fields. Royal blue indicates an unmatched object. The object definition information is listed at the bottom of the page, and a sorted list of total object interest is listed on the right side.

  2. Page 2 is an expanded view of the forecast thumbnail images.
  3. Page 3 is an expanded view of the observation thumbnail images.
  4. Page 4 has images showing the forecast objects with observation object outlines overlaid, and vice-versa.
  5. Page 5 shows images and statistics for matching object clusters (i.e. one or more forecast objects matching one or more observation objects). These statistics also appear in the ASCII output from MODE.
  6. When double-thresholding or fuzzy engine merging is enabled, additional PostScript pages are added to illustrate those methods.
You may view the output NetCDF file using ncview. Execute the following command to view the NetCDF object output of MODE:
ncview mode_120000L_20050807_120000V_120000A_obj.nc &
Click through the 2D variable names in the ncview window to see plots of the four object fields in the file (NOTE: if a window pops up informing you "the min and max are both...", just Click "OK" and then the field will render). The fcst_obj_id and obs_obj_id contain the indices for the forecast and observation objects defined by MODE. The fcst_clus_id and obs_clus_id contain indices for the matched cluster objects.

What are the benefits of spatial methods over traditional statistics? The weaknesses? What are some examples where an object-based verification would be inappropriate?

cindyhg Tue, 06/25/2019 - 08:04