convert a matrix in a struct
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Hi,
I have a nested struct userTouristicTraj(i).touristicData(j).touristicTraj (attached) and I want to convert it in a matrix. I have used this code:
for i=1:25
for j=1:size(userTouristicTraj(i).touristicData,2)
A(i)=userTouristicTraj(i).touristicData(j).touristicTraj
end
end
but it doesn't do what I want, can you help me? thanks
采纳的回答
Guillaume
2017-3-21
You haven't attached your data. The following may do what you want:
datasize = numel(userTouristicTraj(1).touristicData);
touristicTraj = zeros(numel(userTouristicTraj), datasize);
for trajidx = 1:numel(userTouristicTraj) %don't hardcode end of loop when you can ask matlab for the actual value
assert(datasize == numel(userTouristicTraj(trajidx).touristicData), 'touristicData size is not consistent');
for dataidx = 1:numel(userTouristicTraj(trajidx).touristicData)
touristicTraj(trajidx, dataidx) = userTouristicTraj(trajidx).touristicData(dataidx).touristicTraj
end
end
Note: I'm not sure why you have size(userTouristicTraj(i).touristicData,2) in your code, which implies that the touristicData field is 2D. Yet you only iterate over one dimension. I have assumed that the field is 1D. I have also assumed that touristicTraj is scalar. And of course, all the touristicData fields must be the same size.
If any of these assumptions are broken, the code above won't work.
4 个评论
elisa ewin
2017-3-21
Guillaume
2017-3-21
Well, yes, two of the assumptions are broken:
- the number of elements in the field touristicData varies from 0 to 56 instead of being constant
- the number of elements in the field touristicTraj is not scalar, but 2D and the number of rows varies
userTouristicTraj(1) has 11 touristicData, while userTouristicTraj(3) has 37 of them. userTouristicTraj(1).touristicData(1).touristicTraj is 2x3, |userTouristicTraj(3).touristicData(10).touristicTraj is 6x3. Bearing in mind that a matrix must be rectangular, how are you planning to store these in a matrix?
elisa ewin
2017-3-21
编辑：elisa ewin
2017-3-21
Guillaume
2017-3-21
So you just want to concatenate them vertically, regardless of their index:
touristicTraj = zeros(0, 3);
originalindices = zeros(0, 2);
for trajidx = 1:numel(userTouristicTraj)
for dataidx = 1:numel(userTouristicTraj(trajidx).touristicData)
touristicTraj = [touristicTraj;
userTouristicTraj(trajidx).touristicData(dataidx).touristicTraj]; %#ok<AGROW>
originalindices = [originalindices;
repmat([trajidx, dataidx], size(userTouristicTraj(trajidx).touristicData(dataidx).touristicTraj, 1), 1)]; %#ok<AGROW>
end
end
I've also created a matrix originalindices which tells you which index of userTouristicTraj and touristicData corresponds to each row of the final array. If you don't need that simply removes the two relevant lines.
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