numbering of matrices generation

hi if i have

for j=1:3;
B=[A(j,1); A(j,1)]
end;

then how i got the matrices B1 B2 B3 instead of only B .

[KSSV]

How we would know how you got it without telling what is A and what you wanted?

Answer 1

[Stephen23]

>> A = randi(9,3,1)
A =
 6
 5
 9
>> B1 = A([1,1],1)
B1 =
  6
  6
>> B2 = A([2,2],1)
B2 =
  5
  5
>> B3 = A([3,3],1)
B3 =
  9
  9

But almost always creating numbered variables is a really bad idea. Just use indexing instead, because indexing is faster, more reliable, neater, and easier to read and understand than trying to create variable names dynamically. Read these to know why:

http://www.mathworks.com/matlabcentral/answers/225435-save-variable-as-string-from-user-input

http://www.mathworks.com/matlabcentral/answers/267329-list-values-of-variables-with-wildcard

http://www.mathworks.com/matlabcentral/answers/196952-how-to-create-new-variables-in-batches-with-strcat

Or even better is to learn how to use MATLAB properly and avoid the loop altogether and use indexing:

>> A([1,1],1)
ans =
   6
   6
>> A([2,2],1)
ans =
   5
   5

Or if you really want to split A up into smaller matrices:

>> B = num2cell(A(:,[1,1]).',1);
>> B{1}
ans =
   6
   6
>> B{2}
ans =
   5
   5