How do you split up a matrix into 2 matrices where the rows are made up of the rows from the initial matrix containing certain numbers?

How do you split up a matrix into 2 matrices were the rows are made up of the rows from the initial matrix containing certain numbers?

For example if I have the matrix,

J = [1 2 3 77 5; 77 1 2 77 3; 1 2 3 4 5; 1 2 3 4 5; 1 77 3 4 5; 1 2 3 4 5]

and I want,

A = [1 2 3 77 5; 77 1 2 77 3; 1 77 3 4 5]

and,

B = [1 2 3 4 5; 1 2 3 4 5; 1 2 3 4 5]

So far I have the code shown below, but I am not 100% sure if this is correct?

if true
  % rows=size(J,1);
cols=size(J,2);
for i=1:1:rows
  for u=1:1:cols
      if J(i,u)==77
          B=[
end

Any help would be appreciated, thanks!

[Joel Meyer Espinoza]

does this help

J = [1 2 3 77 5; 77 1 2 77 3; 1 2 3 4 5; 1 2 3 4 5; 1 77 3 4 5; 1 2 3 4 5]

A(1,:)=J(1,:);

A(2,:)=J(2,:);

A(3,:)=J(5,:);

A

B(1,:)=J(3,:);

B(2,:)=J(4,:);

B(3,:)=J(6,:);

B

[Adam Danz]

So the rule you're following is to extract all rows that have 77 in them into matrix A and then but the remaining rows into matrix B?

[Zabih Siddiqi]

I done that initially Joel, but I want the code where it would work for any matrix regardless of size. Thanks for the help anyway!

[Zabih Siddiqi]

Yes Adam that is the rue I am following.

Answer 1

[Fangjun Jiang]

Contain77InRow=any(J==77,2);
A=J(Contain77InRow,:)
B=J(~Contain77InRow,:)

[Zabih Siddiqi]

That's exactly what I was looking for! Thanks!

Answer 2

[Adam Danz]

If your goal is to extract rows from J that contain 77 and place them in A while placing all other rows in B,

rowIdx = any(J==77,2); 
A = J(rowIdx, :); 
B = J(~rowIdx, :);

[Zabih Siddiqi]

Yeah that's exactly what I wanted. Thanks!