Hi,
I understand that you want to create a vector b with the conditions as defined using for / if / else statements.
There are two ways to create the vector b as specified.
%way 1 using loop and other statements
x = [0:0.5:5.0]
b = [];
for i=1:numel(x)
if(x(i)<1)
b = [b,x];
elseif(x(i)>=1 && x(i)<=4)
b = [b,x(i)^2];
else
b = [b,4];
end
end
b
%way 2
x = [0:0.5:5.0];
b = [X(X<1), (X(X>=1 & X<=4)).^2 ];
k = x(x>4);
k(:,:) = 4;
b = [b,k]