Mercurial > hg > ltpda
comparison m-toolbox/classes/@time/datenum.m @ 0:f0afece42f48
Import.
| author | Daniele Nicolodi <nicolodi@science.unitn.it> |
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| date | Wed, 23 Nov 2011 19:22:13 +0100 |
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| -1:000000000000 | 0:f0afece42f48 |
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| 1 % DATENUM Converts a time object into MATLAB serial date representation | |
| 2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
| 3 % DESCRIPTION: Converts a time object into MATLAB serial date number. A serial | |
| 4 % date number of 1 corresponds to Jan-01-0000. The year 0000 is merely a | |
| 5 % reference point and is not intended to be interpreted as a real year. | |
| 6 % | |
| 7 % NOTE: time objects formatting routines use the timezone specified in the LTPDA | |
| 8 % toolbox preferences, while MATLAB time routines always work in the local time | |
| 9 % zone, as specified by the operating system. This conversion routine is built | |
| 10 % so that the time string representation obtained by time.format() and the one | |
| 11 % obtained from datestr(datenum(time)) are equivalent: | |
| 12 % | |
| 13 % >> t1 = time(); | |
| 14 % >> datestr(datenum(t1)) === t1.format('dd-mmm-yyyy HH:MM:SS') | |
| 15 % | |
| 16 % However, except in the cases where the timezone is set to UTC in the LTPDA | |
| 17 % toolbox preferences, this implies that: | |
| 18 % | |
| 19 % >> datenum(time()) ~= now() | |
| 20 % | |
| 21 % VERSION: $Id: datenum.m,v 1.2 2010/07/29 18:07:55 nicolodi Exp $ | |
| 22 % | |
| 23 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% | |
| 24 | |
| 25 function num = datenum(obj) | |
| 26 | |
| 27 % number of seconds since 1970-01-01 00:00:00.000 UTC | |
| 28 num = double(obj); | |
| 29 | |
| 30 % take care of timezone offset | |
| 31 num = num + time.timezone.getOffset(num * 1000)/1000; | |
| 32 | |
| 33 % divide by 60*60*24 to convert into days and add offset computed in local time | |
| 34 num = num / 86400 + datenummx(1970,01,01,00,00,00); | |
| 35 | |
| 36 % NOTE: the MEX function datenummx() is used instead of the datenum() MATLAB | |
| 37 % function to save time of the expensive input arguments checks performed by | |
| 38 % the later | |
| 39 | |
| 40 end | |
| 41 |