syms t x y z Fx=cos(t);y=sin(t);z=2*sin(t)^2-1;F=[x^2*y , (1/3)*x^3,x*y ]  ; %场函数V=[diff(x,t),diff(y,t),diff(z,t)];r= int(dot(F,V),t,0,pi*2) %点积后积分double(r)