How to filling a blank matrix with designated patterns using a single for loop?

Hello everyone,

I am wondering how to fill a 17x17 all zeros matrix with a specific pattern. Specifically, I intially created a 17x17 zero matrix and I have a matrix whose size is 1x289 where 289 is a result of 17x17. In here, I want to fill in the all zero 17x17 matrix with the existed matrix(1x289) using the code below such that:

Matrix_A = zeros([17 17]);

ii = 1:17:289;

jj = 1:1:17;

for kk = 1:length(ii)

a = ii(kk);

b = jj(kk);

Matrix_A(17,b) = existed_matrix(:,a);

end

The logic of this algorithm above is that I start to fill in the matrix from bottom to top. As a result, the column 1 and column 2 in the 17th row will seperated by 16 numbers in the existed matrix. Please see the diagram below. However, by using the code above, I only can fill in the blank in the 17th row. This means that I have to create 17 different for loops in order to fill in all 17 rows with the exsited_matrix.

Is there anyway to fill in all 289 blanks using only 1 for loop? I know the only place we need to modify in the code is "Matrix_A('another variable',b) = existed_matrix(:,a). This is where I got stuck.

Please help,

Thank you

Answer 1

[Steven Lord]

reshape your vector into a matrix of the appropriate size then flip the matrix. No for loop required.

If you're required (by a homework assignment, for example) to use a for loop, you could reshape then reverse each column in turn.

Answer 2

[Anahi Bermudez]

Matrix_A = zeros([17 17]);

ii = 17:-1:1;

for kk = 1:length(ii)

existed_matrix(:,kk) = ii;

ii=ii+17;

end

[Taoooooooooooo]

Hi Anahi Bermudez,

I guess I did not make myself clear while I was asking questions. Basically, I want to fill in a 17x17 blank matrix by using the number from the existed_matrix in a way as shown in the diagram above in the question window. I am not trying to modify the exisited_matrix.

Sincerely,

Tao

[Anahi Bermudez]

Oh, so you need to define existed matrix

Matrix_A = zeros([17 17]);

ii = 1:17:289;

jj = 17:17:289;

existed_matrix=1:length(Matrix_A)^2;

for kk = 1:length(ii)

Matrix_A(:,kk) = existed_matrix(jj(kk):-1:ii(kk));

end

good luck :)