Convert ordered date to formal matlab date
조회 수: 1 (최근 30일)
이전 댓글 표시
How to convert the following sequence of date to formal y/m/d or Matlab date format
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/145721/image.png)
댓글 수: 0
채택된 답변
José-Luis
2014년 10월 14일
Note that you'd still need the year. But if you know that then:
your_date = datenum(your_year-1, 12, 31, 0, 0, 0) + ordinal_day;
Ordinal_day goes from 1 to 365.
댓글 수: 2
dpb
2014년 10월 14일
What about leap years? OP shows multiple years possible in his listing w/o a starting year hint. Of course, he may be ignoring them...
추가 답변 (3개)
Kelly Kearney
2014년 10월 14일
syear = 1900; % Year corresponding to first set of numbers
x = repmat(1:365, 1, 3)'; % Your data
yr = cumsum(x == 1) + (syear - 1);
dn = datenum(yr, ones(size(yr)), x); % datenumbers
If you want to format the date, you can use datestr:
>>datestr(dn(1))
ans =
01-Jan-1900
댓글 수: 0
dpb
2014년 10월 14일
편집: dpb
2014년 10월 15일
Don't try to "convert", just create. Given the first year and length of the list, the date number vector would simply be
ystrt=2000; % or whatever
dn=datenum(ystrt,1,[1:length(dates)].',1);
datenum is smart enough to roll over the days by month and year including leap years.
댓글 수: 0
Sean de Wolski
2014년 10월 14일
Or in R2014b you can do this with the new and improved datetime class:
datetime(2014,1,1:365,0,0,0)'
댓글 수: 4
dpb
2014년 10월 15일
OK, so you were merely intending to emphasize the class as a class rather than some really enhanced functionality.
Wonder how the class implementation compares to "deadahead" array function performance-wise. Altho datenum is notoriously slow for all it's checking perhaps TMW has cleaned up a bunch of that and it's as fast or even faster...my machine here is limited and R2012b brings it to just barely tolerable performance so I've not tried the later revisions and I'm not at all eager to change UI.
Sean de Wolski
2014년 10월 15일
The class does have some enhanced functionality, especially when it comes to plotting and time zones.
I haven't measured the performance of it. Maybe Peter will chime in.
참고 항목
카테고리
Help Center 및 File Exchange에서 Dates and Time에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!