How to convert decimal hour and calculate the average every 5 min?
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Marcelo Duarte
on 15 Nov 2013
Commented: Marcelo Duarte
on 18 Nov 2013
Hello all! I'm a beginner at Matlab and I need to solve a problem. First, I need to convert the UT columm from decimal hour to hour:minute:seconds. Then, I need to calculate every 5 minutes on average the ROT collumn and show the reply in a new matrix (hour:min:sec,rot mean).
Example:
e.g. UT (5.404)=0.404*60=24.252; 0.252*60=15.12 ,then UT(5.404)=5:24:15 hours:min:sec
Thanks in advance
Marcelo
2 Comments
Doug Hull
on 15 Nov 2013
Why are you dropping the 0.004 in the first step?
>> [Y, M, D, H, MN, S] = datevec(5.404/24)
Y =
0
M =
0
D =
0
H =
5
MN =
24
S =
14.4000
Accepted Answer
Walter Roberson
on 16 Nov 2013
sprintf('%02d:%02d', H, MN)
In order to show this "together" with the ROT, you will need to indicate the mechanism you wish to use to "show" it. Are you referring to a uitable() for example?
Ordinary numeric matrices cannot hold a combination of strings and numbers.
3 Comments
Walter Roberson
on 17 Nov 2013
bin_num = 1 + floor(ut(:) * 60 / 5) - floor(ut(1) * 60 / 5);
max_bin_num = max(bin_num);
rot_quad = rot.^2;
rot_quad_mean5 = accumarray(bin_num, rot_quad(:), [], @mean);
rot_mean5 = accumarray(bin_num, rot(:), [], @mean);
rot_mean_quad5 = rot_mean5 .^ 2;
ROTI_5 = sqrt(rot_quad_mean5 - rot_mean_quad5);
first_date_vec = datevec(ut(1) * 24);
first_date_hour = first_date_vec(4);
first_date_min5 = floor(first_date_vec(5) ./ 5) .* 5;
first_date_ser = datenum([0 0 0 first_date_hour first_date_min5 0]);
bin_date_vecs = datevec(addtodate(first_date_ser, 5 * (0:max_bin_num-1), 'minute'));
ROTI_matrix = [bin_date_vecs(:,4), bin_date_vecs(:,5), ROTI_5];
Now, ROTI_matrix will be an array, first column the hour of each 5 minute interval, second column the minute of each 5 minute interval, third column the corresponding ROTI for the 5 minute interval.
More Answers (1)
Andrei Bobrov
on 17 Nov 2013
k = rem(UT,1)*60;
tms = fix([UT,k]);
m = ceil(k/5)*5;
[~,b,ii] = unique(m);
out = [tms(b,:), accumarray(ii,ROT,[],@mean)];
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