define time period for each year

Hi all,

I wish to re-define my time period.

The initial time period is as following:

The time period ranges from 01-10 (1st of Oct.) till 30-04 (30th of Apr.).

The range is defined by months only. The array 'Date' contains datetime value that is in yyyy-MM-dd format.

% starting month
sm = 5;
% ending month
em = 9;
% starting day
fd = 1;
% ending day
ld = 30;

PERIOD_1 = find(month(Date)<sm) | month(Date)>em)
PERIOD_2 = find(month(Date)>(sm-1) & month(Date)<(em+1))

As for a new time period, I wish to use both day values ('starting day' and 'ending day') as well, because if not...

i won't be able to define period that does not start on the 1st of a month (e.g. 04-10 till 27-04).

Thank you!

Answer 1

[Walter Roberson]

[y, m, d] = ymd(YourDataTable.Date);
mask = m >= sm & m <= em & (m > sm | d >= fd) & (m < em | d <= ld);

selected_entries = YourDataTable(mask,:);

[Peter Perkins]

I was gonna say that it should also be possible to simplify this logical test by using 'dayofyear'. That makes it just

d = day(YourDataTable.Date,'dayofyear');
mask = d < 120 | d >= 274

but then ... stupid leap years! Still, you could modify that a bit to work.

[Walter Roberson]

Though the poster did say that the range was defined by month only, so

m = month(YourDataTable.Date);
mask = m <= 4 | m >= 10;
selected_entries = YourDataTable(mask,:);

I think my earlier code was selecting in the opposite sense, as I did not notice that they wanted October to April.