how to create a vector inside a loop?

i need to vector that saves mse final value and than plot it. how do i do that? how to create vector that saves all the answers?

if true
  % code
end
function [finalW, MSE, Numiterations] = gradientDescentLinearNeuron(x, t, lr, ErrorGoal, MaxIterations)
FinalW=(2*rand(1,(size(x,1)))-1)/10; 
MSE=1/(size(x,2)*((sum(t-FinalW*x).^2)));
%ErrorGoal=0.15;
%lr=0.1;
step=1;
while ((MSE>ErrorGoal)&&(step<=MaxIterations))
 y=FinalW*x;
 dMSEdw=-1/((size(x,2)*((t-y))*x'));
 FinalW=FinalW-lr*dMSEdw;
 MSE=1/(size(x,2)*((sum(t-FinalW*x).^2)));

   step=step+1;
end
vectorMSE=
plot(vectorMSE,step);

end

Answer 1

[madhan ravi]

a=1:10;    %an example
i = 1;
while i<=numel(a)

b(i) = a(i).^2;  %(i) in order to avoid overwriting
i=i+1;
end
b

[madhan ravi]

b is now a vector likewise adapt it to your case

[ariellewin11 ariellewin11]

will it work inside a while loop?

[madhan ravi]

see edited answer