How to correct the invalid expression error when i have the correct delimiters and multiplication operator?

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I am trying to run this code, but i am getting the invalid expression error for line 6. All parathensis are correct:
xz(t)=e^(j*pi*m(t));
xp(t)=pi*m(t);
xI(t)=cos(pi*m(t));
xQ(t)=sin(pi*m(t));
Ts=50;
t=(0:Ts:3);
m(t)=((t>=0)f(t<1)).*(-1+2*t)+((t>=1)f(t<2)).*(2-t);
Invalid expression. Check for missing multiplication operator, missing or unbalanced delimiters, or other syntax error. To construct matrices, use brackets instead of parentheses.

Error in connector.internal.fevalMatlab

Error in connector.internal.fevalJSON
plot(t,pi*m(t));q0xp(t);
plot(t,cos(pi*m(t)));qoxz(t);
plot(t,sin(pi*m(t)));qoxQ(t);

Answers (1)

Benjamin Kraus
Benjamin Kraus on 22 Feb 2022
This is an invalid MATLAB expression:
(t>=0)f(t<1)
Specifically, this is invalid:
(t>=0)f
It is unclear what you intend for MATLAB to do? Should MATLAB multiply a logical vector with the value of f? What is the value of f? If you want MATLAB to do an element-by-element multiplication of the value of (t>=0) with the value of f then you need this:
(t>=0).*f
And this may be invalid, depending on the value of f and t.
f(t<1)
In this case (t<1) will be a logical vector and f can either be a function or index. If f is a function, then you are calling that function with a logical vector. If f is a variable, then you will get an invalid index for any value that is less than 1, becase 0 is not a valid index for a MATLAB vector (which is 1-based).

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