use "for loop" to create pattern

I would like to know how to modify my "second for loop" to obtain the "a" result as below picture.

Thank you very much!

clc
clear

plynumber=3;
stackply=3;
plysym=1;
total=plynumber*stackply*plysym;

for i=1:plynumber   % first for loop
     a(1,i)=input('a=')
end

for i=1+plynumber:total % second for loop

[Image Analyst]

OK, so that is your desired final a, but is supposed to depend on your a from loop 1 at all? Or you just want that a regardless of what a was from the first loop? Because I think to get your desired a, it's basically going to totally ignore the a from your first loop.

[Mark]

Yes, I would like to depend on my loop 1 because I need to analyze my plynumber first in my program. I would like to create a input for my program so that's why I create the first for loop to store my input. The purpose is to make the every input I enter can follow the pattern as the picture I posted.

Answer 1

[David Hill]

Why not just use repmat() instead of a for-loop?

a=repmat(a,1,3);

[Mark]

Thanks David! repmat is more easier to use! How about creating a symmetric pattern as below picture. Could I also use repmat founction?

[David Hill]

a=[45 -45 0 0 -45 45];
a=[repmat(a(1:3),1,2),repmat(a(4:6),1,2)];

[Mark]

Could you generate a=[45 -45 0 0 -45 45] by using repmat as well? Or is there any other way to generate this pattern? Thanks!

[David Hill]

a=[45 -45 0];
a=[a,flip(a)];

[Mark]

Got it! Thanks!