Add matrix to matrix

Let's say: A=zeros(7,2):

 A=[ 0  0         
     0  0        
     0  0     
     0  0        
     0  0         
     0  0 
     0  0]

 B=[4 1 3] ; C=[1 1 1] ;
 D=[2 5 7 6]; E=[2 2 2 2]

How can I add two matrix B,C,D,E to matrix A to get the result as follows:

 F=[ 4  1        ......add B, C.......    
     1  1        ......add B, C.......
     3  1        ......add B, C.......
     2  2        ......add D, E.......
     5  2        ......add D, E......
     7  2        ......add D, E......
     6  2]       ......add D, E......

In general, let's say :

A=zeros(1000,2)

B1=[1; 2; 3;....100]   ;  index_B1= [1;1;1;.....1]  {100 element 1}
B2=[101;102;103....300];  index_B2= [2;2;2;.....2]  {200 element 2}
B3=[301;302;303....600];  index_B3= [3;3;3;.....3]  {300 element 3}
..................................................................
B7=[801;802;803....850];  index_B7= [7;7;7;.....7]  {50 element 7}
...................................................................
Bi=[921;922;923....1000];  index_Bi=[i;i;i;.....i]  {80 element i}

1/ How to create matrix index_Bi according to the number of element in matrix Bi? (If possible please use while or for ...loop to do)

2/ After that, How to add two matrices (Bi & index_Bi) to matrix A, we will have the result:

 F=[ B1  index_B1         
     B2  index_B2        
     B3  index_B3     
     ..............      
     B7  index_B7        
     .............
     Bi  index_Bi]

[Stephen23]

"if possible please use while or for ...loop to do" It is possible, but it is not a good way to write code. You should read this to know why, and what the better alternatives are (hint: indexing):

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

Answer 1

[Andrei Bobrov]

B = {B1;B2;B3;B4...;Bi}; % Please create B array.

n = cellfun(@numel,B);
A = [cell2mat(B),repelem((1:numel(n))',n)];

[ha ha]

In your code, you don't use "the initial matrix A=zeros(1000,2) " , right?

[Andrei Bobrov]

The stupid question.

Where is the source data?

[ha ha]

Sorry. Because I run your your code with my example. I need to use the matrices B1,B2...Bi... data only. I don't use the input matrix A=zeros(1000,2). It also show the result. So, that's why I ask you?

clear; clc;

 B1=[4; 1; 3] ;
 B2=[2; 5; 7; 6];
 B = {B1;B2}; % Please create B array.
 n = cellfun(@numel,B);
 RESULT = [cell2mat(B),repelem((1:numel(n))',n)];

or

 clear; clc;

 B1=[4 1 3] ;
 B2=[2 5 7 6];
 B = {B1';B2'}; % Please create B array.
 n = cellfun(@numel,B);
 RESULT = [cell2mat(B),repelem((1:numel(n))',n)];

I try to run this code, and the the result is the same as my expectation---> GOOD CODE

But actually, I wanna assign matrix B1,B2,B3...Bi to the first colum of matrix A (beacause i can not create the array B={B1;B2;B3;..;Bi} in my algorithm.

[Guillaume]

You should never have matrix B1, B2, ... Bn in your workspace. As soon as you start numbering matrices, you should stop and change the way you work. These numbered matrices are obviously relatedm they should therefore be stored together into a single container variable such as the cell array that Andrei used.

[ha ha]

Hi Guillaume,

Please see this post for "clear question"

https://jp.mathworks.com/matlabcentral/answers/354722-add-index-matrix-to-matrix?s_tid=email_ans_new_ans_ans_h#answer_279839

Answer 2

[KL]

   N = [B.' C.';
       D.' E.'];
   F = A+N

Why E has only 3 elements? I'd assume you missed out something there.

[ha ha]

Yes. E should have 4 element (sorry I omitted it). please see my edit question

Answer 3

[Guillaume]

In your particular example, and assuming that E is supposed to have 4 elements instead of the 3 you've written:

 F =  A + [B.', C.'; D.', E.']

I have no idea where you're going with this question, so can't answer in a generic way.

[ha ha]

please see my edit question