Symbolic computaion of complex number and using eval function doesnot

syms a real;
syms b real;
syms x;
l=a+b*1i;
m=2*a+b*1i;

x=[l m; -m l];
 for i= 1:5
a=i;
b=i+1;
eval(x)
end
When I use eval function for this symbolic computation I get output as some real numbers. This just a sample code. Similar logic I am using it in for some problem but the ouput is not coming as desired.
The output eval(x) should come as complex numbers.
Can any one help in this small issue? I would be highly thankful.

Answer 1

[Walter Roberson]

Do not use eval() on symbolic expressions. Symbolic expressions have a different syntax and semantics then MATLAB expressions do.

You should be using subs() instead of eval()