structure

Hello, I have a structure that has got 20 values :

temp_q(j)=struct('ff' ,{temp_Q});

I have something like this

>> temp_q(1,1).ff{1,1}

ans =

    0.0046    0.2417

>> temp_q(1,1).ff{2,1}

ans =

    0.0844    0.9421

>> temp_q(1,1).ff{3,1}

ans =

    0.2599    0.5752

>> temp_q(1,1).ff{4,1}

ans =

    0.1818    0.8212
>> temp_q(1,1).ff{5,1}

ans =

    0.1450    0.4509

>> temp_q(2,1).ff{1,1}

ans =

    0.5499    0.6477

>> temp_q(2,1).ff{2,1}

ans =

    0.3998    0.9561

>> temp_q(2,1).ff{3,1}

ans =

    0.8693    0.6491

But i want to make it like this label it as

>> temp_q.Q1

ans =

    0.0046    0.2417
    0.0844    0.9421
    0.2599    0.5752
    0.1818    0.8212
    0.1450    0.4509

>> temp_q.Q2

ans =

      0.5499    0.6477
      0.3998    0.9561
      0.8693    0.6491

Thanks in advance

[Fangjun Jiang]

You can't really do that as you try to make temp_q a cell array but has different field names for every element.

%%

clear temp_q

temp_q(1,1).ff={{0.0046,0.24171};{0.0844,0.9421};{0.2599,0.57522};{0.1450,0.45093};{0.1450,0.45094}};

temp_q(2,1).ff={{0.5499,0.6477};{0.3998,0.9561};{0.8693,0.64911}};

S_Name=strcat('Q',cellstr(num2str((1:2)','%d')));

S=cell2struct({temp_q.ff},S_Name,2)

You can reference S.Q1{1,1}, S.Q1{5,1}, S.Q2{1,1}, S.Q2{3,1}

[developer]

But for doing this i have to put some check to look into all 20 structure cells

temp_q(1,1).ff={{0.0046,0.24171};{0.0844,0.9421};{0.2599,0.57522};{0.1450,0.45093};{0.1450,0.45094}};

temp_q(2,1).ff={{0.5499,0.6477};{0.3998,0.9561};{0.8693,0.64911}};

or is there any easy method to do this ??

[Fangjun Jiang]

No!!! That is just for me to mimic your data structure.

What is your ORIGINAL data and what is its format? Did you use temp_q(j)=struct('ff' ,{temp_Q}) to construct your structure and then want to change the fieldname? Is temp_Q your original data? What is the size and class of your temp_Q data? Can you provide an example?

[developer]

Yes i am making temp_q the same as you have told and temp_Q is a cell and its coming each time from loop like first order is 5x1 time its has elements

0.0046 0.2417

0.0844 0.9421

0.2599 0.5752

0.1818 0.8212

0.1450 0.4509

second time its order changes as loop gives the values and order 3x1

0.5499 0.6477

0.3998 0.9561

0.8693 0.6491

and so on

[developer]

temp_Q=cell(r2,1);

for i=1:r2

temp_Q(i,:)=P(temporary_mat(i,2));

i=i+1;

end

temp_q(j)=struct('ff' ,{temp_Q});

temp_q=temp_q';

[Fangjun Jiang]

You've come a long way! If you have temp_Q in cell array already. We could have saved all those comments.

%%

temp_Q{1}=[0.0046 0.2417

0.0844 0.9421

0.2599 0.5752

0.1818 0.8212

0.1450 0.4509];

temp_Q{2}=[0.5499 0.6477

0.3998 0.9561

0.8693 0.6491];

S_Name=strcat('Q',cellstr(num2str((1:2)','%d')));

S=cell2struct(temp_Q,S_Name,2)

[developer]

but if you see temp_Q is of order(r2,1)means each time cell will update so yo cannot have

temp_Q{1} or temp_Q{2}

[Fangjun Jiang]

Please provide temp_Q here so I can copy and paste to use it. In your comment above, I don't have your variable P and temporary_mat.

A=cell(3,1) will result in 3x1 cell and can be referenced using A{1},A{2} and A{3}. There is no need to use A{1,1},A{2,1} and A{3,1}

[Fangjun Jiang]

replace this portion of the code

temp_Q=cell(r2,1);

for i=1:r2

temp_Q(i,:)=P(temporary_mat(i,2));

i=i+1;

end

temp_q(j)=struct('ff' ,{temp_Q});

temp_q=temp_q';

with

temp_Q=P(temporary_mat(:,2));

temp_q.(num2str(j,'Q%d'))=cell2mat(temp_Q);

And check the result of temp_q afterwards.

[developer]

Yes it works now thanks alot :)

[Fangjun Jiang]

Great! Now since the question has been answered. Please consider reading this post for hints on how to ask a better question. Please also accept the question to indicate that the solution is valid. Many of your questions were answered but not accepted.

http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

Answer 1

[Fangjun Jiang]

You mean like this?

temp_Q=1:20;
temp_q=struct('ff',mat2cell(temp_Q,1,repmat(1,20,1)))

[developer]

actually temp_q has order <20x1>, i have given it name as the first value has got the variable name as Q1 ,second value as Q2 and so on.

[Fangjun Jiang]

temp_q above is a 20x1 structure. What do you mean 'name it'?

[developer]

Yes i want name the 20 values of structure temp_q from Q1 to Q20 instead of 'ff'

[developer]

With help of a loop

[Fangjun Jiang]

You mean rename the fieldname of the structure, as change from temp(1,:).ff to temp(1,:).Q1?

[developer]

Yes

[Fangjun Jiang]

rmfield() and setfield() can be used to change the field name of a structure. But you have a strcture array. You can't have temp_q as a 20x1 structure array but has different fieldname for each element of the array.

clear T;

T.ff=1;

T=setfield(T,'Q1',T.ff);

T=rmfield(T,'ff');

clear S;

S=struct('ff',{1,2});

>> S(1)=setfield(S(1),'Q1',S(1).ff)

??? Subscripted assignment between dissimilar structures.

[Fangjun Jiang]

What I suggest is this:

S_Name=strcat('Q',cellstr(num2str((1:20)','%d')));

S_Data=mat2cell(temp_Q,1,repmat(1,20,1));

S_Temp=[S_Name';S_Data];

S=struct(S_Temp{:})

[developer]

But i have to assign it to all values Q1 to Q20 to make the code generic instead of renaming the values one by one

X=rand(20,1);

Y=rand(20,1);

p = mat2cell([X Y],ones(20,1),2);

f=cellstr(strcat('p',strjust(num2str((1:20)'),'left')));

temp=[f p]';

P=struct(temp{:})

But here i have temp_q structure of order 20x1, instead of matrix X and Y

[developer]

If you run the above code you will get to know what i actually meant

[Fangjun Jiang]

Okay,

%%

temp_q=struct('ff',mat2cell(rand(20,2),repmat(1,20,1),2));

S_Name=strcat('Q',cellstr(num2str((1:20)','%d')));

S_Temp=[S_Name';{temp_q.ff}];

S=struct(S_Temp{:})

[developer]

But i am getting this error

>>Array dimensions of input 4 must match those of input 2 or be scalar.

As in above example you can see that the elements of the structure are 1x2 matrix of type double but in my case the the values of temp_q are cell values of different sizes like first value is 5x1 second is 4x1 etc

[Fangjun Jiang]

In that case, use a for-loop like Wlater provided below might be easier. The point of using struct() without loop is to construct the proper 'fieldname'/data pairs. If your data is in cell array, the above won't work. I'll play with it, but, what's wrong with using a for-loop?!

[Fangjun Jiang]

All right, hope this one provides a satisfying answer. In fact, all the code above could use cell2struct(). It's easier than constructing the fieldname/data pairs.

%%

temp_q(1).ff={1,2,3,4,5};

temp_q(2).ff={1,2,3,4};

temp_q(3).ff=magic(2);

S_Name=strcat('Q',cellstr(num2str((1:3)','%d')));

S=cell2struct({temp_q.ff},S_Name,2)

S =

Q1: {[1] [2] [3] [4] [5]}

Q2: {[1] [2] [3] [4]}

Q3: [2x2 double]

[developer]

its also not working in my case , is it possible that i can sent u my structure temp_q so that u can understand what i want?

[Fangjun Jiang]

Please update your question. I think you need to update it anyway as it didn't describe what you want anyway. Use three elements of temp_q should be sufficient. Make the data representative.

[developer]

Please check it again if it makes some sense.

[Fangjun Jiang]

See comments in your question.

Answer 2

[Walter Roberson]

for K = 1:length(temp_q)
  temp_Q.(sprintf('Q%d', K)) = temp_q(K).ff;
end