Step 28: Delete “unsafe” (or unwanted) GPS benchmarks from your dataset(s)

There might be several reasons for wanting to edit some GPS benchmarks out of your NeoKinema input dataset .gps:

· You received a list of “unsafe” benchmarks from NeoKinema in Step 27.

· You noticed strong coseismic or postseismic velocity anomalies in Step 18 (and were not able, or not willing, to fix these in Step 19).

· Some of the benchmarks are so far away that they could never be within the area of your (current or future) .feg grid area.

If you are NOT using a GPS-velocity covariance matrix (.gp2 file), then you can manually delete GPS benchmarks from your .gps file
at any time.  (You can also sort their order within the .gps file, based on any criterion you like.)
My utility program Delete_Cracked_Benchmarks might save you some time if you received a long list of “unsafe” benchmarks.

If you ARE USING a GPS-velocity covariance matrix (.gp2 file), then you can never delete any benchmarks manually!
This would destroy the connections between the .gps file and the .gp2 file, making the .gp2 file worse than useless—actually misleading!
In such cases, it is necessary to use my utility program Delete_Cracked_Benchmarks to modify both files in parallel!

Delete_Cracked_Benchmarks will read in:

· Your current .gps file

· Your current .gp2 file (if any)

· A list of benchmarks to be deleted.

The list-to-be-deleted should be copied (with any plain-ASCII text editor, such as NotePad or EditPad Pro)
from the table of “unsafe” benchmarks provided by NeoKinema in its log-file t*.nko (e.g., see Step 27).
Don’t copy any of the header lines or trailer lines; just the essential list of benchmarks.
This list should be copied-and-pasted into a small ASCII file, whose name you will provide to the Delete_Cracked_Benchmarks utility program.
If you wish, you can add more benchmarks to the list which is to be deleted;
the critical identifier of each benchmark will be its (longitude, latitude) coordinates, which must be supplied with 0.001° precision (or better).

Delete_Cracked_Benchmarks will end by writing:

· A new .gps file of benchmarks to be kept, and

· A new .gps file of benchmarks that were segregated (deleted), and perhaps

· A new .gp2 file (if an old .gp2 file was provided).

Remember to tell NeoKinema about these changes by changing the name of the .gps file (and .gp2 file?) in its parameter file!

OPTION: At this point, you might want to re-run NeoKinema, which will probably succeed in finishing the calculation.

OPTION: You might also want to try making some plots of the output with NeoKineMap.
            However, if you create a map of the azimuths of most-compressive principal strain-rate directions (Overly #11),
            you might notice that they do not look regionally-consistent, or even dynamically reasonable!
            We will fix this in the next Step.