MET Online Tutorial

MET Online Tutorial for METv3.0

Wavelet-Stat Tool: Run

Next, run Wavelet-Stat on the command line using the following command:

    bin/wavelet_stat \
    tutorial/out/pcp_combine/sample_fcst_24L_2005080800V_12A.nc \
    tutorial/out/pcp_combine/sample_obs_2005080800V_12A.nc \
    tutorial/config/WaveletStatConfig_tutorial \
    -outdir tutorial/out/wavelet_stat \
    -v 2

Wavelet-Stat is now performing the verification task we requested in the configuration file. It should take several seconds to run. Generally, the Wavelet-Stat tool runs pretty quickly.

When Wavelet-Stat is finished, it will have created 4 files: 2 ASCII statistics files, a NetCDF scale decomposition file, and a PostScript summary plot. Open up the PostScript summary plot using the PostScript viewer of your choice, gv, or Ghostview, for example:

    gv tutorial/out/wavelet_stat/wavelet_stat_240000L_20050808_000000V.ps

This PostScript summary plot contains 5 pages. The first page summarizes the definition of the tile(s) in the domain. The remaining pages show the difference field (f-o) for each decomposed scale and the statistics for each scale.

Now, let's modify the configuration file and rerun this case. Again, open up the tutorial/config/WaveletStatConfig_tutorial file and edit it as follows:

  • Set grid_decomp_flag = 0;
    To let the Wavelet-Stat tool automatically define the largest 2^n by 2^n tile that fits in the center of the domain.

Now, rerun the Wavelet-Stat command listed above, and when it is finished, reload the PostScript plot. On the first page of the PostScript plot, note the following:

  • A tile of dimension 128 by 128 was chosen in the center of the domain. Since the dimension increased from 64 (= 2^6) to 128 (= 2^7) the number of scales has increased by 1.
  • The tile chosen includes a large amount of missing data in the observation field. You should try to avoid including missing data when running the Wavelet-Stat tool as it will cause misleading results.

Close that PostScript file.