28.1 Merge events near in time ASSOCI

The program will check if two events are close together in time and merge the events if requested. This is partly an alternative to use append in EEV. The program asks for maximum time difference between events to associate. The user will then be asked if events should be physically associated or not. The program is useful when merging a large number of events.

NOTE: The times used for comparison is the origin time in an s-file and the data base file name for a data base. There be a large difference between the origin time and datta base s-file name, so if critical, do an update first with UPDATE and synchonize the file names.

The program has two alternatives for merging:

1. Merge events in same data base: One event is compared to the next event in the same data base. If they are close enough in time, the two events are merged and the program moves on to the next event. If 3 events are close in time, only the 2 first are merged. In order to also merge the third, the program has to be run again.
2. Merge events from a file into the data base: This option makes it possible to merge from another data base (use SELECT or COLLECT to create a file) without first completely mixing the two. The event from the file will be merged with as many files from the data base as fit the time difference criteria. So e.g. 2 events from the data base can both get the same event from the file included.

   At the end of the run, three files are output (associ_rest.out, associ_merg.out and associ_base.out) with events from file which were not merged, events that were merged and events from data base that were appended too, respectively. These can then be put into another data base with split, if desired. This function can also be used to separate the input file in two files.

   Note: When merging within one data base, the first event will get the next one merged into it. If merging from file into a data base, the event in the data base will by default always be the first and keep the main header. This thus a safe method when you want to keep the main header uncheged in the data base. Optionally you can decide to always put the header from the file first.

Putting new data in a data base where locations are available in one place and waveform files have to be merged in:

Use AUTOREG to make a data base with s-files with only waveform file names. This is done by using the option to copy or move waveform files to the WAV structure and the s-files will be made in a data base of the same name.

Use ASSOCI to merge in the s-files with locations and phases from a file and use the option to put the headers from the file first.

If the event files are put into the data base first, then the s-files from AUTOREG will also go into the data base (with opeion to move or copy waveform files the WAV data base) and ASSOCE will have to merge files which all are in the data base. Then there is no control whinch header comes first.