Statistics

pyTRACK.stats_track(outdirectory=None, keep_all_files=False)

Workflow to compute statistics from features tracked using track_uv().

The statistics file are output inside the corresponding {hemisphere}_y{year} folder in the outdirectory.

Parameters:

• outdirectory (str) – Path to the output directory, same as that passed to track_uv()

• keep_all_files (bool) – Do you want to keep all the intermediate files? Default is no. Turn this on if you want to retreive these files, or during development.

The stats_track function computes the track statistics from track_uv() output. This workflow runs stats in every {hemisphere}_y{year} directory and writes two files - stats_ff_trs_pos.nc and stats_ff_trs_neg.nc, associated the statistics of the positive and negative vorticity anomalies.

These files have the following fields-

1. mstr - mean intensity (/s)

2. stdstr - std of intensity (/s)

3. msp - mean speed (m/s)

4. stdsp- std of speed (m/s)

5. fden - feature density (cyclones/ 5 degree spherical cap)

6. gden - genesis density (genesis/ 5 degree spherical cap)

7. lden - lysis density (lysis/ 5 degree spherical cap)

8. tden - track density (cyclones/ 5 degree spherical cap)

9. xvel - x component of mean velocity (m/s)

10. yvel - y component of mean velocity (m/s)

11. mlif - mean lifetime

12. mgdr - mean growth/decay rate (unitless)

13. miso - mean anisotropy

14. xor - x component of mean orientation vector

15. yor - y component of mean orientation vector

16. mten - mean tendency

17. marea - mean area (steradian, multiply by (Radius of earth)^2 to get units of km^2)

stats_track() also outputs other files - to see all of them, pass keep_all_files=True