How to extract a column from cell arrays matrix?

Dear MATLAB users,

I wish I got your help for this problem. I have built a cell arrays as a matrix as follow

for k=1:5
out{k}(1,:}=
out{k}(2,:}=
out{k}(3,:}=
end

I am trying to extract the the first element in first array from each cell. i have tried this out{1:5}(1,1) but it does not work however if i type out{1}(1,1) this give the first element but in specific cell also out{1:5} shows all cell matrices. The error I saw when i tried out{1:5}(1,1) was Expected one output from a curly brace or dot indexing expression, but there were 5 results.

Thank you in advance. Best Aziz

[Stephen23]

You should consider simplifying how your data is arranged. Simpler data means simpler code. Simpler code means code is easier to write, and has fewer bugs.

For example this data might be better stored in an ND cell array, or perhaps even a simple numeric array (vector/matrix/ND).

[Abdulaziz Abutunis]

Thank you Stephen, you are totally right. I just do some adjustment to an old code. I will consider your advice in the future. Appreciate it

[Walter Roberson]

Abdulaziz Abutunis comments to Stephen:

He did not solve the problem but he did give a good advice to avoid this problem in the future. he even gave more than one option.

Answer 1

[per isakson]

One way

>> cellfun( @(a) a(1,1), out )
ans =
    0.9572    0.0357    0.7060    0.0344    0.7094

however, a for-loop might be a better choice

[Abdulaziz Abutunis]

Thank you per isakson this is exactly what i am looking for... appreciate it

[Walter Roberson]

Abdulaziz Abutunis comments to per isakson

I could not find similar answer to my question and he provided it in an easy way

[Abdulaziz Abutunis]

Hi per isakson, I am a little greedy :) and looking for extra assistance. Do you know if it is possible to write a number say 1 to the column we read earlier. Thank you in advance.

[Image Analyst]

It might be easier is you save your data out to a .mat file and attach it. Then he could write code using your actual data.

[per isakson]

@Abdulaziz Abutunis, Create some sample data

for ii = 1:5
    for jj = 1:3
        out{ii}(jj,:) = ii*100 + jj*10 + (1:3)';
    end
end

Inspect the value of the first cell

>> out{1}
ans =
   111   112   113
   121   122   123
   131   132   133

Inspect one specific element of the value of the first cell

>> out{1}(3,2)
ans =
   132
>>

Caveat: I'm not sure I understood your question.

[Abdulaziz Abutunis]

I should have said thanks again a long time ago:). I already used your suggestions

Thanks a lot

Answer 2

[Image Analyst]

You can't have out{k}(1,:} because you got two closing braces and no closing parenthesis. Maybe you meant out{k}(1,:). See the FAQ: http://matlab.wikia.com/wiki/FAQ#What_is_a_cell_array.3F and try to avoid cell arrays in most cases, definitelyif you have rectangular numerical array of constant dimensions, it just complicates things.

[Abdulaziz Abutunis]

you right it was a typo sorry and thanks for pointing this out

Answer 3

[Juvinch Vicente]

I'm not sure if this would work for the older version, but for version above 2016b, this line works.

cellMatrix = {'A', 'B', 'C'; 'A', 'B', 'C';'A', 'B', 'C'};

if you want the first column,

firstCol = cellMatrix(:,1);

and so forth.

[Abdulaziz Abutunis]

Thank you Juvinch for the suggestion. I will consider when I use the cell array again