Easy Noob Indexing Question

I'm sure this answer is looming in front of me but I am missing it somehow. I have an array

A = [0 0;1 -1; -1 1;1 -1; -1 1];

and

B = [2 -2; -2 2;2 -2; -2 2;2 -2; -2 2;2 -2;0 0];

and I'm concatenating these two in the vertical direction but I only want rows 4:7 of my concatenated output.

I am doing this in two steps.

C = cat(1,A,B); % or some other calculation of vectors A and B

C = C(4:7,:);

How can I reduce this to one command by directly indexing the equation of "cat(1,A,B)" directly into C?

I know that I could do this by C = cat(1,A(end-1:end,:),B(1:2,:)). A and B are of variable length and I only want C to hold the concatenation +/-2 indices vertically. Is there another way in a single line?

[KALYAN ACHARJYA]

Is there any issue with that, simplest and easiest?

C=[A;B];
C=C(4:7,:)

[Image Analyst]

My programs have thousands of lines of code. Why does yours have to be just one line of code instead of 2? Your last way of using end will work for variable sizes arrays.

Answer 1

[Rishabh Mishra]

Hi,

Use the code below for resolving your issue:

C=[A;B]; 
C=C(4:7,:); 

This is the simplest way to code the solution for the issue you are facing.

Hope this helps !

[Richard Keniuk]

I guess I already had this to the "cleanest" implementation. I thought maybe I was missing something here.

Thanks for your help.