matlab含贝塞尔函数的方程

hyfang

为什么每次解出来的都是 empty sym

clear all;                             % 清理
clc;
clf;
syms a b arfa m a b u
m=1;
a=90;
b=300;
u=0.3;
H11 =besselj(m,arfa*b);
H12 =besseli(m,arfa*b);
H13 =bessely(m,arfa*b);
H14 =besselk(m,arfa*b);

H21=m/(arfa*b)*besselj(m,arfa*b)-besselj((m+1),arfa*b);
H22=m/(arfa*b)*besseli(m,arfa*b)+besseli((m+1),arfa*b);
H23=m/(arfa*b)*bessely(m,arfa*b)-bessely((m+1),arfa*b);
H24=m/(arfa*b)*besselk(m,arfa*b)-besselk((m+1),arfa*b);

H31 =besselj(m,arfa*a)-(1-u)*(m*(m-1)/(arfa*a)^2*besselj(m,arfa*a)+1/(arfa*a)*besselj((m+1),arfa*a));
H32 =-(besseli(m,arfa*a)+(1-u)*(m*(m-1)/(arfa*a)^2*besseli(m,arfa*a)-1/(arfa*a)*besseli((m+1),arfa*a)));
H33 =bessely(m,arfa*a)-(1-u)*(m*(m-1)/(arfa*a)^2*bessely(m,arfa*a)+1/(arfa*a)*bessely((m+1),arfa*a));
H34 =-(besselk(m,arfa*a)+(1-u)*(m*(m-1)/(arfa*a)^2*besselk(m,arfa*a)+1/(arfa*a)*besselk((m+1),arfa*a)));

H41 =m*besselj(m,arfa*a)-(arfa*a)*besselj((m+1),arfa*a)+m^2*(1-u)/(arfa*a)^2*((m-1)*besselj(m,arfa*a)-(arfa*a)*besselj((m+1),arfa*a));
H42 =-(m*besseli(m,arfa*a)+(arfa*a)*besseli((m+1),arfa*a)-m^2*(1-u)/(arfa*a)^2*((m-1)*besseli(m,arfa*a)+(arfa*a)*besseli((m+1),arfa*a)));
H43 =m*bessely(m,arfa*a)-(arfa*a)*bessely((m+1),arfa*a)+m^2*(1-u)/(arfa*a)^2*((m-1)*bessely(m,arfa*a)-(arfa*a)*bessely((m+1),arfa*a));
H44 =-(m*besselk(m,arfa*a)-(arfa*a)*besselk((m+1),arfa*a)-m^2*(1-u)/(arfa*a)^2*((m-1)*besselk(m,arfa*a)-(arfa*a)*besseli((m+1),arfa*a)));
A=[H11 H12 H13 H14; H21 H22 H23 H24; H31 H32 H33 H34; H41 H42 H43 H44]
A=det(A)
solve(A,arfa)

[ 本帖最后由 hyfang 于 2010-7-4 11:22 编辑 ]