How do I add a column vector or matrix to a 6X6 original matrix?

I have a 6x6 matrix, say C_m, in which some entries are zero and all other entries are cloumn vector c11, c12 & c44 eg c11 = [a11,a12,a13...], c12 = [b11,b12,b13...], c13 = [d11,d12,d13...], c44 =[e11,e12,13...]. All column vectors are of the order of 142x1 matrix.

How do I define the column vectors in a 6x6 matrix (C_m), so that matlab recognizes it?

C_m = [c11 c12 c12 0 0 0

c12 c11 c12 0 0 0

c12 c12 c11 0 0 0

0 0 0 2*c44 0 0

0 0 0 0 2*c44 0

0 0 0 0 0 2*c44]

When i run the program, following problem occur? how do i solve this?

Error using horzcat
Dimensions of matrices being concatenated are not
consistent.

Error in bilal2 (line 287)
287      C_m =   [c11 c12 c12 0 0 0

[Stephen23]

If C_m is a numeric matrix then you can't: each element of a numeric matrix contains exactly one numeric value.

If C_m is not required to be a numeric matrix then you could try a cell array:

https://www.mathworks.com/help/matlab/cell-arrays.html

[M.Bilal]

numeric matrix means square matrix?

If C_m is numeric matrix, then how do matlab recognize it?

Does specifying the position of entries in the C_m matrix helpful, so that matalb understands it?

[M.Bilal]

When i run the program, this problem occur? how do i solve this?

Error using horzcat
Dimensions of matrices being concatenated are not
consistent.

Error in bilal2 (line 287)
287      C_m =   [c11 c12 c12 0 0 0

[Stephen23]

"numeric matrix means square matrix?"

No, its size is totally irrelevant. A numeric matrix has numeric type, e.g. double, single, uint8, etc.:

https://www.mathworks.com/help/matlab/numeric-types.html

which means that a numeric array/matrix is NOT char, cell, structure, table, duration, or any other type:

https://www.mathworks.com/help/matlab/matlab_prog/fundamental-matlab-classes.html

"When i run the program, this problem occur?"

Read my first comment.

"how do i solve this?"

Read my first comment.

[M.Bilal]

"If C_m is a numeric matrix then you can't: each element of a numeric matrix contains exactly one numeric value."

Well, C_m is a numeric matrix, now how to proceed further?

And all i need, is the resultant matrix C_m should be of the order of 142x1.

[M.Bilal]

Hello, Stephen Cobeldic Kindly suggest me on following, as i am new to Matlab.

how i use a cell array in this problem. If you can learn me through an example, it will realy help me.

"If C_m is not required to be a numeric matrix then you could try a cell array:"

Thanks in advance

[Guillaume]

Before blindly trying things without understand what the implications are, please explain why you want to store several somethings that have size 142x1 into something that is size 6x6? Shouldn't the container be big enough to store the containee?

What are you planning to do afterward with C_m ? Yes, you could make C_m a cell array, but you won't be able to perform mathematical operations on the cell array itself, only on individual cells.

[M.Bilal]

Thanks Guillaume for your response

Well, C_m is a stiffness matrix, in which c11,c12,c44 etc are stiffnesses.

c11, c12,c44 are column matrix , not a single value. I am planning to develop C_m matrix which contains c11,c12,c44.

Answer 1

[Philippe Lebel]

here is an example:

clear all
zeros_col = zeros(142,1);
c11 = (1:142)';
fantastic_matrix = [c11 zeros_col zeros_col zeros_col zeros_col zeros_col;
                    zeros_col zeros_col zeros_col zeros_col zeros_col zeros_col;
                    zeros_col zeros_col zeros_col zeros_col zeros_col zeros_col;
                    zeros_col zeros_col zeros_col zeros_col zeros_col zeros_col;
                    zeros_col zeros_col zeros_col zeros_col zeros_col zeros_col;
                    zeros_col zeros_col zeros_col zeros_col zeros_col zeros_col]
                

That is if you want to have a matrix in order to compute some things with matrix multiplications.

If you want to just store things:

clear all
c11 = (1:142)';
fantastic_cell_array = {c11 0 0 0 0 0;
                    0 0 0 0 0 0;
                    0 0 0 0 0 0;
                    0 0 0 0 0 0;
                    0 0 0 0 0 0;
                    0 0 0 0 0 0}

[Stephen23]

Note that [] is a concatenation operator, and is totally superfluous on these lines:

c11 = [1:142]';

which is why it is highlighted by the MATLAB Editor, together with the recommended solution:

[Philippe Lebel]

ancient matlab version does not show me the righteous path. I appologize for my sins for i am only mortal.

:P

i eddited my answer

[M.Bilal]

Thanks you very much Philippe Lebel, for your timely anticipation to my query.

Thanks Stephen Cobledick as well.

It will really work for me. I am working on it.

[Philippe Lebel]

all right! mark the answer as accepted if it works for you!

[M.Bilal]

Hello, Philippe Lebel, i have 1 more question. Kindly help me.

I am trying to solve equation (eq. is written below). I am facing many problems in order to get final result. What i need is S_eff at the end as 6x6 cell array. if you can suggest me possible ways of solving such equations.

Thanks in advance

S_eff = S_d + (((S_d - S_m) * I6 * (S_d - S_m))/(phi*(I2*S_m*I2' - 1/k_f) - I2*(S_d - S_m)*I2'));
% Here, S_d,S_m, are 6x6 cell array while phi and 1/k_f are single values say phi=0.2, k_f=2
 % I2 =[1 1 1 0 0 0]; 1x6 matrix
 % I6 = I2'*I2; 6x6 matrix

[Guillaume]

As I wrote as a comment to your question, "Yes, you could make [..] a cell array, but you won't be able to perform mathematical operations on the cell array itself"

You haven't really answered my question and until you do, any answer you're given is probably not going to work. In the above equation, S_eff, S_d, etc. must be matrices. If they are 6x6 matrices, then you need to explain why you're trying to store over 142 elements in something that can only store 36 elements.

Note that at this point, this is not even a matlab issue. In mathematics, each element of a matrix is a single number, not itself a matrix or a vector. So, I'm sorry but "C_m is a stiffness matrix, in which c11,c12,c44 etc are stiffnesses. c11, c12,c44 are column matrix , not a single value" makes no sense mathematically.

[Philippe Lebel]

Guillaume is right. We don't know what you are trying to do. Also, we attempt to provide help on matlab problems. Your problems now seem to be more on the mathematics/physics side.

[M.Bilal]

Guillaume, Thank you for your detailed reply..

Your question:

"explain why you're trying to store over 142 elements in something that can only store 36 elements. "

Well, S_eff can be solved by using single value in elements of all matrices.( means without 6x6 cell array).

But I DON'T NEED IT.

I am not using single vlaues at this time. I have to used whole wellog file at this time which consist of 1 cloumn and 142 rows, means a column vector. And this wellog file say c11 should be store in C_m matrix as element, similarly c12, c13, c44. My problem is that how can i solve S_eff by using S_d,S_m which consist of elements of column vectors like c11, c12, c13, c44.

"What are you planning to do afterward with C_m ? Yes, you could make C_m a cell array, but you won't be able to perform mathematical operations on the cell array itself, only on individual cells."

I got a clue from last line of yours which means i can perform mathematical operations on individual cells. This sentence is saying that i can use only those elements of array which consist of c11,c12,13,c44 for further caluculation like for the solution of S_eff.

[Guillaume]

Again, forget about matlab for now. In mathematics you don't store vectors as elements of a matrix. This bit makes no sense.

[M.Bilal]

Right.so nice of you. Thanks for time.

Answer 2

[Steven Lord]

C_m =        [c11 c12 c12 0 0 0
                   c12 c11 c12 0 0 0
                   c12 c12 c11 0 0 0
                    0 0 0 2*c44 0 0
                    0 0 0 0 2*c44 0
                    0 0 0 0 0 2*c44]

If all of the c* variables are 142-by-1 vectors, you need to concatenate them with zero vectors that are also 142-by-1. Consider a smaller example:

V = [1; 2; 3];
D1 = [V, 0] % Fails
D2 = [V, zeros(size(V))] % Works

If you want to concatenate together 0's and vectors, you may want to make a variable that contains a zero vector of the appropriate size to make the sizes match.

V = [1; 2; 3];
Z = zeros(size(V));
A = [V Z Z; Z V Z; Z Z V]

[M.Bilal]

Steven Lord, thankyou v.much for impressive answer. I am working on it.