Data from array struct in corresponding shape - arrays

Question

Say, we have an array of structs
data = struct('position',[]);
data(1,1).position = 11;
data(1,2).position = 12;
data(2,1).position = 21;
data(2,2).position = 22;
I learned that to get the entries from a field from all structs in the array, we can use
>> [data.position]
ans =
11 21 12 22
But this gives the data in a row. How can we get it in the original shape of the array, without looping the array in MCode?
Desired output:
position =
11 12
21 22

Answer 1

Use reshape. This will restructure an input vector / matrix into another vector / matrix of a desired shape. Specifically, you can specify the dimensions of data into reshape as well as the row vector produced by [data.position] and it'll reshape the vector with the right dimensions for you.
data = struct('position',[]);
data(1,1).position = 11;
data(1,2).position = 12;
data(2,1).position = 21;
data(2,2).position = 22;
position = reshape([data.position], size(data))
position =
11 12
21 22
Note that the elements are shaped in column-major format so the values are stacked column-wise. As you can see, the first two elements become the first column of the output matrix, while the last two elements become the second column of the output matrix.

Answer 2

If you are working with empty entries, you can use struct2cell to convert the struct data into cell array that enables us to store empty entries as empty cells -
data_cell = permute(struct2cell(data),[2 3 1])
out = data_cell(:,:,strcmp(fieldnames(data),'position'))
So, if you have something like this with the (2,2) missing -
data = struct('position',[]);
data(1,1).position = 11;
data(1,2).position = 12;
data(2,1).position = 21;
You would have -
out =
[11] [12]
[21] []
Based on #CitizenInsane's nice observation and which might be very close to #rayryeng's answer, but one that deals with cell arrays instead of numeric arrays, would be this -
out = reshape({data.position}, size(data))