assimble small victors into bigger one using for loop

what if I have vector a1= [1; -1] and a2= [ 1 ;-1 ] and so on ... the big matrix should be like F= [ 1; 0; 1] if the size was(2) how can I do that in a for loop ?

[abdelrahman alhammadi]

sorry I meant F = [ 1;0;-1]

[Walter Roberson]

What is the rule? Is it like

A1 followed by zeros, plus
0 followed by A2 followed by zeros, plus 
0 0 followed by A3 followed by zeros

And so on, with one more leading 0 for each variable?

If so are they all the same length?

Are the variables numbered consecutively and are there too many to write out by hand?

[Bruno Luong]

You should reply to Torsen and John on another thread, and probably better learn your lesson and FEM or learn to express clearly when ask people for help.

[Stephen23]

"what if I have vector a1 ... and a2 ... and so on ... "

then your code should be redesigned:

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

[abdelrahman alhammadi]

yeas if I have a vectors of the same length and I want to assemble them in bigger one

Answer 1

[Bruno Luong]

a1= [1; -1];
a2= [1 ;-1];

a = {a1 a2};
F = zeros(length(a)+1,1);
for i=1:2
  F(i+[0,1]) = F(i+[0,1]) + a{i};
end

Answer 2

[Image Analyst]

Lacking any specific and complete rules other than giving a1, a2, to use a for loop, and to give the desired F, this works:

a1 = [1; -1] 
a2 = [1 ; -1] 
for k = 1 : 3
    F(k) = 2 - k;
end