Matrix storage and extraction inside a cell or a strucutre array.
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How do I store matrix and extract matrix from a cell or a structure by using a for loop??????
a=[1 2 3;4 5 6;7 8 9]
b=[11 12 13;14 15 16;7 8 19]
c=[121 212 213;14 15 16;27 28 29]
I created an cell array by following method
d=[{a},{b},{c}]
Suppose I have to retrive b from d. How do I retrive it????
Suppose a,b,c are images represented in matrix form. I need to know if these matrix can be stored in a structure or in a cell array by using a for loop and later retrived by a for loop.
1 Comment
Stephen23
on 3 May 2020
Simpler:
d = {a,b,c};
"Suppose I have to retrive b from d. How do I retrive it????"
Basic indexing:
b = d{2};
Accepted Answer
Ameer Hamza
on 3 May 2020
Edited: Ameer Hamza
on 3 May 2020
You can use curly bracket indexing with cell arrays. To extract the content of the second element from cell array 'd', run
b = d{2};
Also, note that you should never create a related variable with different names. So instead of creating a, b, c, and then using for loop to create cell array or struct. It is better to create the cell array to being with. There are ways to create cell array using for-loop using eval(), but it is highly unrecommended in MATLAB. See the reason here: https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval
2 Comments
Ameer Hamza
on 4 May 2020
Yes you can do that. For example
s = struct(); % empty struct
s(1).a = rand(1,10); % create field a in struct
s(2).b = rand(2,20); % create field b and assign value to second
% element in struct array
However, all the elements in the struct array will have the same field names. If you don't assign a value to a specific field of an element of struct array, then It will be an empty vector. Run the above code to see the value of fields 'a' and 'b' for both elements of struct array 's'.
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