[MATLAB基础] 矩阵求特征值的问题

[qy469110098]

syms x b
digits(4)
n=10
c=1/180*pi
d=5
z=sqrt(2)/(c^2)
%A=[0 -1 -2
%1 0 -1
%2 1 0]
A=1
Y1=besselj(0,A)
Y2=0
%Y2=zeros(3)
for i=1:n
Y2=Y2+besselj(2*i,A).*(cos(2*i*b)*(z+4*i^2*pi*exp(-pi*z))/(z^2+(2*i)^2))
end
Y3=Y1+2*Y2
Y4=0
%Y4=zeros(3)
for i=1:n
Y4=Y4+besselj(2*i+1,A).*(sin((2*i+1)*b)*(z-(2*i+1)^2*pi*exp(-pi*z))/(z^2+(2*i+1)^2))
end
Y5=2*Y4
Y6=sqrt(Y3.^2+Y5.^2)
Y7=d.*Y6
Y71=vpa(Y7)
B=2
Y8=besselj(0,B)
Y9=0
%Y9=zeros(3)
for i=1:n
Y9=Y9+besselj(2*i,B).*(cos(2*i*b)*(z+4*i^2*pi*exp(-pi*z))/(z^2+(2*i)^2))
end
Y10=Y8+2*Y9
Y11=0
%Y11=zeros(3)
for i=1:n
Y11=Y11+besselj(2*i+1,B).*(sin((2*i+1)*b)*(z-(2*i+1)^2*pi*exp(-pi*z))/(z^2+(2*i+1)^2))
end
Y12=2*Y11
Y13=sqrt(Y10.^2+Y12.^2)
Y14=d.*Y13
Y141=vpa(Y14)
S=[1 Y71 Y141
Y71 1 Y71
Y141 Y71 1]
E=eig(S)
%E=eig(Y7)
e1=E(1)
e2=E(2)
e3=E(3)
y=1/2*(e1^2*(1-sqrt(e1/(1+e1)))/(e1-e2)/(e1-e3)+e2^2*(1-sqrt(e2/(1+e2)))/(e2-e1)/(e2-e3)+e3^2*(1-sqrt(e3/(1+e3)))/(e3-e2)/(e3-e1))
ezplot(b,y)
grid
报错

??? Error using ==> sym.eig at 56
Error, (in evala/preproc3) floats not handled yet

Error in ==> JZ_test3 at 47
E=eig(S)
哪位高手帮帮忙，谢谢