'Undefined function 'atan2' for input arguments of type 'sym'.'에러가 뜬는데 어떻게 해결해야되나요?

바터워즈 함수의 위상을 2~5차까지 구하기 위해서 다음과 같은 함수를 작성하였습니다.

syms w
clc;clear;
syms w
for m = 2:1:5
    for n = 1:1:m
      a(n)=(-1*sin(((2*n-1)*pi)/(2*m))+i*cos(((2*n-1)*pi)/(2*m)));
      if n==1
        F=1/(i*w-a(n));
      else
        F=F*1/(i*w-a(n));
      end
    end
    ezplot(angle(F),[0,2.5])
    hold on
    grid on
end

그리고 결과는

Undefined function 'atan2' for input arguments of type 'sym'.

Error in angle (line 14)
p = atan2(imag(h), real(h));

Error in Untitled4 (line 13)
    ezplot(angle(F)* 180/sym('PI'),[0,2.5])

다음과 같이 떳습니다. 어떻게 하면 위 문제를 해결할 수 있나요? 도와주시면 감사하겠습니다.

Answer 1

[Steven Lord]

The ANGLE and ATAN2 methods for symbolic objects were introduced in release R2013a according to the Release Notes. Are you using an earlier release?

[paul]

thanks about your help....

Answer 2

[Image Analyst]

Instead of sym('PI') simply use pi

ezplot(angle(F)* 180/pi, [0, 2.5])

[paul]

It's not work...... I think I misunderstand your answer. please teach me one more time.

[Image Analyst]

Why does your code say

ezplot(angle(F),[0,2.5])

while your error message says

ezplot(angle(F)* 180/sym('PI'),[0,2.5])

Please attach your actual script with the paper clip icon. Also, what value do you expect "w" to be?