MATLAB: Converting Day of Year to month and day

Question

Dear All

I have the following data:

epoch=    '96318.74847837'
      '96319.62211352'
      '96319.62351606'
      '96319.62356237'
      '96320.05952563'
      '96320.49676119'

the firs 2 elements of the data is year '96' and rest is the day of year '318.74847837'. I got the following code to separate them.

year=cellfun(@(y) y(1:2),epoch,'uni',false);
day=cellfun(@(y) y(3:5),epoch,'uni',false);

And the following code to convert day of year to date and month.

doy=318;
dayspermonth = [0 31 28 31 30 31 30 31 31 30 31 30 31];
mm = ones(size(doy))*NaN;
dd = ones(size(doy))*NaN;
for im = 1:12
   I = find(doy > sum(dayspermonth(1:im)) & doy <= sum(dayspermonth(1:im+1)));
   mm(I) = ones(size(I)).*im;
   dd(I) = doy(I) - ones(size(I))*sum(dayspermonth(1:im));
end

I would like to take the input of day into doy so that I have a single array of doy with all the results from day.

I know this code is not taking care of leap year. but if someone can help me with that I would be grateful.

Thanks!!

Answer 1

% Let y - our year
y = 1996;
doy = 318.25;
[yy mm dd HH MM] = datevec(datenum(y,1,doy));

variant of full solution

x=    {'96318.74847837'
      '96319.62211352'
      '96319.62351606'
      '96319.62356237'
      '96320.05952563'
      '96320.49676119'} % initial array
a = str2double(x);
y = fix(a/1000);
[yy mm dd HH MM SS] = datevec(datenum(y,0,a - y*1000)); % corrected