How can I insert row into matrix without deleting its values?

Hello all! I want to insert row into the matrix, for example I have a=[1,2;4,9;11,12;3,6], and b=[0,0] ; now I want to insert b into a in the third position like this a=[1,2;4,9;0,0;11,12;3,6]. Any ideas?

[Hikaru]

Is there a condition to be satisfied before performing this operation? Is it always going to be the 3rd position?

[Giorgi]

Well its always going to be 3rd position

Answer 1

[Matz Johansson Bergström]

The only way I know of is to create a new matrix consisting of A and the row and then append the three matrices together, for instance

A = [1,1; 2,2; 3,3]; 
b = [6,7]; 
k = 0; %row position, can be 0,1,2 or 3 in this case
A = [A(1:k,:); b; A(k+1:end,:)]

[Matz Johansson Bergström]

It seems that I was actually the first to give the answer, is my solution wrong?

When I did my research I found another solution that works for all kinds of matrices, check it out: insertrows "pick of the week".

[Giorgi]

Well both answers are correct, I also see the link and everything is clear now for me thanks for your response :)

[Matz Johansson Bergström]

Ok, good.

[Guillaume]

Yes, both answers are correct, but the OP can only pick one. FWIW, I voted for yours as it is better formatted than Stalin's.

[Asif Newaz]

nice one mate

[Jayasudha]

Thak you!

Answer 2

[Stalin Samuel]

   a=[1,2;4,9;11,12;3,6],
  b=[0,0] ;
  row_no=3 %%where wants to insert

a(1:row_no-1,:) = a(1:row_no-1,:) 
tp =a(row_no:end,:)
a(row_no,:)=b
a(row_no+1:end+1,:) =tp

[Riyadh Muttaleb]

Hi Stalin,

I would like to insert rows by using loop, your help would be so appreciated,

Riyadh

Answer 3

[Anil Kamat]

Just in case the insert position is variable.

emt_lpfc=[]; emt_rpfc = []; emt_lpmc =[]; emt_rpmc =[]; emt_sma=[];
A = rand(3,3)
emt_lpfc = 1;
emt_sma = 5;
emt_reg = [emt_lpfc emt_rpfc emt_lpmc emt_rpmc emt_sma];
temp = [];
if isempty(emt_reg) == 0
    for i = 1:size(emt_reg,2)
        %for filling rows
        temp = A(emt_reg(i):end,:);
        A(emt_reg(i),:)= zeros(size(A,1),1);
        A (emt_reg(i)+1:end,:) = [];
        A = [A ; temp];
        %for filling columns
        temp = [];
        temp = A(:,emt_reg(i):end);
        A(:,emt_reg(i))= zeros(1,size(A,1));
        A (:,emt_reg(i)+1:end) = [];
        A = [A  temp];
    end
end