How can I split a table at given rows?

I have an n by m table, A, and a vector of indices, idx.

Is there a way to split my table into smaller tables, each beginning with the row indicated in idx?

For example:

A = ['str1', 'str2';
          1,      2;
          3,      4;
     'str3', 'str4';
          5,      6]

idx = [1; 4]

I would like:

A1 = ['str1', 'str2';
           1,      2;
           3,      4]

A2 =  'str3', 'str4';
           5,      6]

Many thanks.

Answer 1

[Sad Grad Student]

Try:

A1 = A(idx(1):idx(2)-1,:);
A2 = A(idx(2):end,:);

you can make that into a loop too if you have more values.

Answer 2

[funkadelala]

Thank you. For looping, I have:

B = zeros(1,length(idx));  

for i = 1:1:length(idx)

    B(i) = A(idx(i):idx(i+1)-1,:);

end

But, this returns the error:

"The following error occurred converting from table to double: Error using double. Conversion to double from table is not possible."

I assume that this is because of mixed data types. How might I correct this?

[Sad Grad Student]

I'm not too familiar with table in Matlab. But I believe the error is because you're declaring variable B as a vector (datatype: double) and trying to pass the table in it. Try using: table2array for conversion but since you have strings as your first row, it might give you issues. So along with table2array , look up: Access Data In Table

Some fidgeting around those commands might help you. Let me know what works! :)

[funkadelala]

Curly indexing did the trick. The working code is:

B = cell(length(idx),1); %preallocates dimensions  

for i = 1:1:length(idx)

    %creates cell array that contains tables; each cell beginning with 
    %index idx(i) of table A, ending on index idx(i+1)-1

    if i ~= length(idx) %if not last pass
        B{i,:} = A(idx(i):idx(i+1)-1,:);

    else
        B{i,:} = A(idx(i):end,:);

    end

end

Thanks!

[Sad Grad Student]

Cool! Congrats :)

Answer 3

[Sad Grad Student]

Solution to this question:

B = cell(length(idx),1); %preallocates dimensions  
for i = 1:1:length(idx)
    %creates cell array that contains tables; each cell beginning with 
    %index idx(i) of table A, ending on index idx(i+1)-1
    if i ~= length(idx) %if not last pass
        B{i,:} = A(idx(i):idx(i+1)-1,:);
    else
        B{i,:} = A(idx(i):end,:);
    end
end

[Sad Grad Student]

Had to write it that way so someone having the same question can access the actual working solution! :)