Hi Soren! Thanks much for answering so quickly!! And so clearly!
2014-03-05 21:21 GMT+01:00 Sören Gebbert <[email protected]>: > Hi Veronica, > > 2014-03-05 20:49 GMT+01:00 Veronica Andreo <[email protected]>: > > Dear list > > > > I'm working with ocean color data set from MODIS and starting to use t.* > > modules... I'm trying now to register the strds and as i'm working with > > 8-day products i specified start date as 2003-01-01 and interval as 8 > days > > for a list of 506 maps. The time series should end by 2013-12-31 and > t.info > > says > > > > ... > > +-------------------- Absolute time > > -----------------------------------------+ > > | Start time:................. 2003-01-01 00:00:00 > > | End time:................... 2014-01-31 00:00:00 > > | Granularity:................ 8 days > > | Temporal type of maps:...... interval > > .... > > Using Python shows that in case of an 8 day's interval, the end date > is computed correctly: > > {{{ > import datetime > print datetime.datetime(2003,1,1) + datetime.timedelta(506*8) > 2014-01-31 00:00:00 > }}} > Actually, it is the same as with grass... it is mathematically correct, but it is not correct for this case... end date of my time series is *2013-12-31* and not 2014-01-31... as i mentioned earlier the problem arises in the last image of each year that covers a 5 or 6 days period (dependending on leap years) and not 8 days as the rest of images in each year... > > The problem arise because all products at the end of the year don't > really > > cover an 8-days period... So, i understand i should add starting and > ending > > date to each file in the list i use as input for t.register... Question > is: > > Is it possible to use DOY instead of dates?? or what would be a > (reasonably) > > easy way of transforming DOY in map names (for example: > > A20030732003080.L3m_8D_CHL_chlor_a_4km_arg) into the corresponding > dates???? > > So your time series has unequal time intervals? Sort of... most of it is every 8 day, excep for the last image of the year... > I would suggest to use > a single input file that lists all maps with time stamps as input for > a single t.register call. > DOY is not supported by t.register. I would suggest that you use the > following Python code to extract the exact start and end time from the > map names: > > {{{ > import datetime > > # 012345678901234567890123456789012345678901 > map_name = "A20030732003080.L3m_8D_CHL_chlor_a_4km_arg" > start_year = int(map_name[1:5]) > start_day = int(map_name[5:8]) > end_year = int(map_name[8:12]) > end_day = int(map_name[12:15]) > > start = datetime.datetime(start_year, 1, 1) + datetime.timedelta(start_day > - 1) > end = datetime.datetime(int(end_year), 1, 1) + datetime.timedelta(end_day > - 1) > > print map_name, "|", start, "|", end > > }}} > > Great!! I really need to learn python :) > Write each map name with start and end time into one file (a single > map name with start and end time each line) and register all maps at > once with "t.register input=my_strds file=my_maps.txt". > > Thanks again! Vero
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