Matlab: sum for two time series dataset? - matlab

Question

I like to sum up the observations of two time series datasets when both of them have observations based on YEAR and DOY. I also like to skip the sum when either dataset has 0 and only do the sum for the maximum observation in that DOY.
Here is the example: data_1 and data_2.
data_1
% YEAR DOY OBS_1
1994 109 0.42
1994 110 0.73
1994 111 0.69
1994 113 0.8
1994 114 0.43
1994 115 0.75
1994 123 0.6
1994 127 0.2
1994 131 0.44
1994 131 0.43
1994 131 0.63
1994 132 0.99
1994 132 0.51
1994 133 0.71
1994 133 0.99
1994 134 0.65
1994 134 0.69
1994 134 0.97
1994 134 0.03
1994 134 0
1994 134 0
1994 135 0.68
1994 135 0.72
1994 136 1.22
1994 136 0
1994 136 0
1994 136 1.28
1994 136 1.34
data_2:
% YEAR DOY OBS_2
1994 110 0.92
1994 111 0.34
1994 113 0.42
1994 114 0.37
1994 115 0.38
1994 122 0.22
1994 127 0.32
1994 131 0.34
1994 131 0.2
1994 132 0.51
1994 132 0.43
1994 132 0.4
1994 133 0.4
1994 134 0.32
1994 134 0.39
1994 135 0.35
1994 135 0.38
1994 135 0.34
1994 135 1.83
1994 135 0.22
1994 135 0.36
1994 135 0.39
1994 135 0.24
1994 135 0.39
1994 136 0.42
1994 136 0.29
1994 136 0.3
1994 136 0.4
1994 136 0.54
1994 136 0.4

Answer 1

Here is a first attempt:
%# maximum day of year
sz = max(max(data_1(:,2)),max(data_2(:,2)));
doy = (1:sz)';
%# get max value for each DOY in each dataset
v1 = accumarray(data_1(:,2), data_1(:,3), [sz 1], #max);
v2 = accumarray(data_2(:,2), data_2(:,3), [sz 1], #max);
%# compute the sum
v = v1 + v2;
%# keep entries where none of the values were zeros
idx = (v1~=0 & v2~=0);
v = [doy(idx(:)) v(idx(:))];
The result:
>> v
v =
110 1.65
111 1.03
113 1.22
114 0.8
115 1.13
127 0.52
131 0.97
132 1.5
133 1.39
134 1.36
135 2.55
136 1.88
I didn't take the year field into account, since its 1994 across all your data...