Moving from scnlobject to channeltag

New capabilities for channeltag

####create using a string.

old usage scnl = scnlobject('STA','CHA','NW', 'LOC')

new usage chaTag = channeltag('NW.STA.LOC.CHA')

multiple channeltags can be initialized with either a cell of strings, or an NxM char array via channeltag.array().

cellArray = {'AV.OKCF..EHZ', 'AV.RSO..EHZ', 'AV.OKER..EHZ'}; % good for arbitrary lists
chaTag = channeltag.array(cellArray);

Working with a char array is often messy, but sometimes it keeps your code simpler.

charArray = ['AV.OKCF..EHZ';'AV.RSO..EHZ ';'AV.OKER..EHZ']; % 3x12 char array
chaTag = channeltag.array(charArray);

Why do I need to use channeltag.array() instead of channeltag()?

By specifying channeltag.array() you are explicitly saying that your code expects one or more channeltags. Conversely, using channeltag() means that the code will error with multiple inputs, which makes for easier debugging.

Additionally, having a separate array constructor means that channeltag() can be streamlined. This is important, since the copy constructor will likely be called many, many times internally.

Parsing routines

channeltag.parse - can return a network, station, location and channel from either a period-delimited string or a channeltag.

s = 'IU.ANMO.00.BHZ'; ct = channeltag('IU.ANMO.00.BHZ');
[N, S, L, C] = channeltag.parse(s);
[N, S, L, C] = channeltag.parse(ct);
% both work and provide the same answer, where N='IU' S='ANMO' L='00' C='BHZ'