transform matrices into a single matrix?

how I can transform matrices into a single matrix? I have 20 - 6x6 matrices, and I need to create 1 matrix for cluster analysis. Thanks!

[KSSV]

what dimension of matrix you want at the end?

[luca buonocore]

20 rows and 6 columns, so 20x6!

[Marc Jakobi]

If you have 20 6x6 matrices, that's a total of 20*6*6 values = 720 values. In an output with 20 rows and 6 columns, you can only fit 120 values. Are you sure you want a 20x6 matrix?

[luca buonocore]

I need to do a hierchical clustering on 20 values, but each values is a 6x6 matrix, so in the end I must clustering returning all 20 values. How I can do that?

[KSSV]

Whats is the criteria for hierchical clustering..

Answer 1

[Massimo Zanetti]

You need to assign each variable to only one row of all_data matrix.

A= [ 1 2 3; 4 5 6; 7 8 9]; 
B= [10 11 12; 13 14 15; 16 17 18]; 
C= [19 20 21;22 23 24; 25 26 27]; 
D= [28 29 30; 31 32 33; 34 35 36]; 
E= [37 38 39; 40 41 42; 43 44 45]; 
F= [46 47 48; 49 0 51; 52 53 54];
all_data = [A(:)';B(:)';C(:)';D(:)';E(:)';F(:)']
Y= pdist(all_data);
Z = linkage(Y,'ward'); 
H = dendrogram(Z,'Orientation','left','ColorThreshold','default'); 
set(H,'LineWidth',1)

[luca buonocore]

thanks massimo! :)

Answer 2

[elias GR]

Make a 3D matrix. If your 6x6 matrices are in the variables A1,A2,...,A20, then:

A=zeros(6,6,20);
A(:,:,1)=A1;
A(:,:,2)=A2;
...
A(:,:,20)=A20;

At the end all the matrices are inside 1 matrix as you wished, A.

[luca buonocore]

very elegant... but I need to do hierarchical clustering with this matrix, how I can convert into a 2D matrix?

[elias GR]

Give us a specific numerical example of what you need

[luca buonocore]

      I have 3 matrices:
        A= [ 1 2 3; 4 5 6; 7 8 9];
        B= [10 11 12; 13 14 15; 16 17 18];
        C= [19 20 21;22 23 24; 25 26 27];
I need to do hierarchical clustering on this variables, and i tried this:
        all_data = [A;B;C];
        Where (A,B,C) are variables

        Y= pdist(all_data)
            Z = linkage(Y,'ward');

         H = dendrogram(Z,'Orientation','left','ColorThreshold','default');
        set(H,'LineWidth',1)
         but MATLAB give me more than 3 values, but I need 3 values back, and no more... 
        How I can do this?