Grouping matrices under a

Hi,

So it is straight forward to do the following,

A = [2; 6; 7; 8; 6] 
B = [7; 1; 6; 3; 4; 9; 8]

C= [A;B] = [2; 6; 7; 8; 6; 7; 1; 6; 3; 4; 9; 8]

Assume that I have several of these matrices that I need to "group". How can I write some code which will do the above but be flexible enough to recognise how many matrices I need to group (the number will vary).

Hope that makes sense.

Craig

Answer 1

[Azzi Abdelmalek]

vertcat(A,B)

If you have many arrays. For example

a=[]  
for k=1:10
    x=(1:k)'
    a=vertcat(a,x)
end

%or

vertcat(a,b,c,d)

[Craig]

perfect thanks!

[Jan]

While loop suffers from a missing pre-allocation, using VERTCAT is clean and clear.

Answer 2

[Image Analyst]

If you use a function to do the stitching, then look at nargin - it will tell you how many input arguments you have, and then varargin will be a cell array with however many arguments you passed in. Then you can loop over that, extracting and stitching as needed.

[Image Analyst]

For example

stitched1 = myStitch(a,b); % Stitch 2 matrices.
stitched2 = myStitch(a,b,c,d,e,f,g,h); % Stitch 8 matrices.