Error: In an assignment A(:) = B, the number of elements in A and B must be the same.

Question

Monserrat Olvera 2023-6-22

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1986799-error-in-an-assignment-a-b-the-number-of-elements-in-a-and-b-must-be-the-same

回答： Torsten 2023-6-22

I have been trying to get all the code to run but it keeps giving me the same error "In an assignment A(:) = B, the number of elements in A and B must be the same".

I managed to calculate w but the operations below are not performed automatically even though I already have the variables I need.

Please, help me!

A=[-1 -2 1 2;-2 3 0 -2;1 0 2 1;2 -2 1 4];
n=4;
v=eye(n,n);
HAH=A;
for k=1:n-2
  x=A(:,n-k+1);
  a2=x.^2;
  alpha2=sum(a2(1:n-k));
  sg=-sign(x(n-k));
  alpha=sg*sqrt(alpha2);
  w=zeros(n-k+1,1);
  for i=1:n-k-1
    w(n-k)=sqrt((1/2)*(1-(x(n-k)/alpha)));
    wnk=w(n-k);
    W(i)=-((1/2)*(x(i)/alpha*wnk));
  end
  w(i)=w;
end
Unable to perform assignment because the left and right sides have a different number of elements.
u=HAH*w;
h=w.'*u;
q=u-(h*w);
HAH=HAH-2*w*q.'-2*q*w.';
H=eye(length(w*w.'))-2*w*w.';
v=v*H;