Hello I'm getting this warning "Variable 'x1' might be set by a nonscaler operator".

This is a exercise to write a piece of code which would determine and plot the odd and even parts of a discontinuous time signal. It's not my code I just copied it from youtube. I would like to know why this code works just fine with continuous time signals and how can I rewrite the code to avoid this issue.

close; clear; clc;

n = -5:5;
A = 0.8;

x1 = A.^n;
x2 = A.^(-n);

if (x1 == x2)
    disp('"The given signal is even!"')
elseif (x1 == (-x2))
    disp('"the given signal is odd!"')
else
    disp('"The given signal in nither odd nor even!"')
end

"The given signal in nither odd nor even!"

xe = ( x1 + x2 )/2;
xo = ( x1 - x2 )/2;

tiledlayout(2,2); nexttile;
stem(n,x1);
xlabel("n");
ylabel("x1(n)");
title("signal x(n)")

nexttile;
stem(n,x2);
xlabel("n");
ylabel("x2(n)");
title("signal x(-n)")

nexttile;
stem(n,xe);
xlabel("n");
ylabel("xe(n)");
title("Even Part of x(n)")

nexttile;
stem(n,xo);
xlabel("n");
ylabel("xo(n)");
title("Odd Part of x(n)")

Answer 1

[Chunru]

close; clear; clc;
n = -5:5;
A = 0.8;
x1 = A.^n;
x2 = A.^(-n);
if all(x1 == x2)        % use all here to ensure all elements of x1 and x2 are same
    disp('"The given signal is even!"')
elseif all(x1 == (-x2))          
    disp('"the given signal is odd!"')
else
    disp('"The given signal in nither odd nor even!"')
end

"The given signal in nither odd nor even!"

xe = ( x1 + x2 )/2;
xo = ( x1 - x2 )/2;
tiledlayout(2,2); nexttile;
stem(n,x1);
xlabel("n");
ylabel("x1(n)");
title("signal x(n)")
nexttile;
stem(n,x2);
xlabel("n");
ylabel("x2(n)");
title("signal x(-n)")
nexttile;
stem(n,xe);
xlabel("n");
ylabel("xe(n)");
title("Even Part of x(n)")
nexttile;
stem(n,xo);
xlabel("n");
ylabel("xo(n)");
title("Odd Part of x(n)")

[AlireaA Mirrabie]

Thanks that was helpful

Answer 2

[KSSV]

You case x1, x2 are vectors and you cannot use the condition like that.

You have to use like shown below.

n = -5:5;
A = 0.8;

x1 = A.^n;
x2 = A.^(-n);

idx = x1 == x2 ;
[x1(idx)' x2(idx)'] 
[x1(~idx)' x2(~idx)']