MET Online Tutorial

MET Online Tutorial for METv3.0

Point-Stat Tool: Output

The output of Point-Stat is one or more ASCII files containing statistics summarizing the verification performed. In this example, the output is written to the tutorial/out/point_stat directory as we requested on the command line. That output directory should now contain 8 files, one each for the CTC, CTS, MCTC, MCTS, CNT, SL1L2, and VL1L2 line types (.txt), and an eighth one for the STAT file (.stat). The STAT file contains all of the output statistics while the other ASCII files contain the exact same data, but sorted by line type.

arrow Since the lines of data in these ASCII files are so long, we strongly recommend configuring your text editor to NOT use dynamic word wrapping. The files will be much easier to read that way.

Open up the tutorial/out/point_stat/point_stat_360000L_20070331_120000V_ctc.txt CTC file using the text editor of your choice and note the following:

  • This is a simple ASCII file consisting of several rows of data.
  • Each row contains data for a single verification task.
  • The first 21 header columns contain data applicable to all line types, such as timing information, variable and level information, verifying message type, masking region applied, interpolation method applied, and threshold values applied.
  • The twenty-first column, labeled LINE_TYPE, indicates the type of statistics contained in this line. In this file, the LINE_TYPE column contains CTC indicating that the columns to follow contain contingency table counts.
  • The remaining columns after LINE_TYPE are labeled FY_OY, FY_ON, FN_OY, and FN_ON and contain the contingency table counts.

Close this file, open up the tutorial/out/point_stat/point_stat_360000L_20070331_120000V_cts.txt CTS file, and note the following:

  • The first 21 columns contain the same type of header data as in the previous file.
  • The LINE_TYPE column is set to CTS which indicates that the columns to follow contain contingency table statistics. Refer to the MET Users's Guide for a thorough description of this output line type.
  • Confidence intervals are given for each of these statistics, computed using either one or two methods. The columns ending in _NCL and _NCU give lower and upper confidence limits computed using assumptions of normality. The columns ending in _BCL and _BCU give lower and upper confidence limits computed using bootstrapping. If you re-ran the Point-Stat example with bootstrapping turned off, the _BCL and _BCU will contain the missing data value of NA.

Open up the tutorial/out/point_stat/point_stat_360000L_20070331_120000V_mctc.txt MCTC file, and note the following:

  • This file contains 6 lines of multi-category contingency table counts.
    These 6 lines are a result of: 3 masking regions * 2 interpolation methods.
  • Since we only provided multiple thresholds for 2-meter temperature, this file only contains MCTC output for that field. Point-Stat used the 3 thresholds we provided to define 4x4 contingency tables. The corresponding statistics are written out in the MCTS file. This functionality is new for METv3.0.

Open up the tutorial/out/point_stat/point_stat_360000L_20070331_120000V_vl1l2.txt VL1L2 file, and note the following:

  • This file contains 24 lines of VL1L2 partial sums.
    These 24 lines are a result of: 3 masking regions * 2 interpolation methods * 4 wind speed thresholds.
  • For the VL1L2 line, the contents of the FCST_THRESH and OBS_THRESH header columns indicate the thresholds that were applied to the wind speed values to determine which U/V points would be included in the sum.

The other output text files contain data specific to their individual line types. Refer to tables 4-2 through 4-19 in the MET Users Guide for a description of their contents.

Lastly, the tutorial/out/point_stat/point_stat_360000L_20070331_120000V.stat STAT file contains all of the same data we just viewed but in a single file. The Stat-Analysis tool, which we'll use later in this tutorial, only reads the STAT output of the Point-Stat, Grid-Stat, Wavelet-Stat, and Ensemble-Stat tools, not the ASCII (.txt) files.