Questions about data types and tables

Data types is not strong side in Matlab, so i'm hoping that someone can help me. See comments in code

%% I'm storing data types of different lenghts as a table. Is a table a good idea?
X1=[9 6 9;3 2 7];
X2=[0 2;4 0];
X3=[3 1 2; 8 9 7];
X=table(X1,X2,X3)

X = 2×3 table
        X1           X2          X3     
    ___________    ______    ___________

    9    6    9    0    2    3    1    2
    3    2    7    4    0    8    9    7

%% The code bellow finds the longest entity in the table and writes out any entities shorter, 
% X2 in this case.
len=table2array(varfun(@(x) size(x,2),X));
lmax=max(len);
idrest=find(len<lmax);
X(:,idrest)

ans = 2×1 table
      X2  
    ______

    0    2
    4    0

%% Now i wish to "fill-out" the shorter enteties by adding 'Nan' as seen bellow. 
% I now wish to store this new strucutre in the place of the original. This
% is the problem that I can't solve. 

for i=idrest(1):idrest(end)
    temp=table2array(X(:,i));
    temp(:,end+1:lmax)=nan
    X.X(:,i)=temp %% Here's the issue
end

temp = 2×3

0 2 NaN 4 0 NaN

Unable to perform assignment because the size of the left side is 2-by-1 and the size of the right side is 2-by-3.

Answer 1

[Dave B]

In your loop, X(:,i) is the contents of the table variable, and you're using it with dot indicating it as the name of the variable.

I believe this is the code you're looking for (I added another variable to make it a slightly more robust test)

X1=[9 6 9;3 2 7];
X2=[0 2;4 0];
X3=[3 1 2; 8 9 7];
X4=[0;2];
X=table(X1,X2,X3,X4)

X = 2×4 table
        X1           X2          X3         X4
    ___________    ______    ___________    __

    9    6    9    0    2    3    1    2    0 
    3    2    7    4    0    8    9    7    2 

len=table2array(varfun(@(x) size(x,2),X)); % or varfun(@(x)size(x,2),X,'OutputFormat','uniform')
lmax=max(len);
idrest=find(len<lmax);

for i = idrest
    temp=X.(i);
    temp(:,end+1:lmax)=nan;
    X.(i)=temp;
end
X

X = 2×4 table
        X1               X2               X3               X4       
    ___________    _______________    ___________    _______________

    9    6    9    0      2    NaN    3    1    2    0    NaN    NaN
    3    2    7    4      0    NaN    8    9    7    2    NaN    NaN