another method to calculate determinant

1 次查看（过去 30 天）

merwan behar 2021-7-23

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/884294-another-method-to-calculate-determinant

评论： darova 2021-7-25

i have this symbolic calculator code and it takes a lot of time to calculate the determinant at the end is there any other method to quickly calculate the determinant

my code

clear 
all  clc
%introduire des variable 
h=1e-9; 
L=10e-9; 
C11=132e9; 
e31=-4.1; 
mu=0; 
E11=5.841e-9; 
E33=7.124e-9;
 ro=7500; B=(pi/h); 
r1=49.5e-9; r2=50.5e-9;
 A=pi*((r2^2)-(r1^2));  
I=pi*(((r2^4)/4)-((r1^4/4))); 
fun1=@(x,r) e31.*(r.^2).*sin(x).*B.*sin(B.*r.*sin(x));
 fun2=@(x,r) E11.*r.*(cos(B.*r.*sin(x))).^2; 
fun3=@(x,r) E33.*(B^2).*r.*(sin(B.*r.*sin(x))).^2;
 F31 = integral2(fun1,0,2*pi,49.5e-9,50.5e-9,'method','iterated'); 
X11 = integral2(fun2,0,2*pi,49.5e-9,50.5e-9,'method','iterated'); 
X33 = integral2(fun3,15,2*pi,49.5e-9,50.5e-9,'method','iterated'); 
%introduire la matrice A 
syms w
 p1=((ro*A*w^2)/(C11*I)); 
p2=((-(mu^2*ro*A*w^2)+(F31^2/X11))/(C11*I)); 
p3=((F31*X33)/(X11*C11*I)); 
p4=(F31/X11); 
p5=(X33/X11);
a=[0 1 0 0 0 0;0 0 1 0 0 0;0 0 0 1 0 0;... (p1) 0 (p2) 0 (p3) 0;0 0 0 0 0 1;0 0 (p4) 0 (p5) 0]; 
H=eye(6);
 a=vpa(a); 
M=expm(a*L); 
%condition aux limite simplement appuyÃ©
 l1=H(1,:); 
l3=H(3,:);
 l5=H(5,:);
m1=M(1,:); 
m3=M(3,:); 
m5=M(5,:); 
%la matrice final
 K=[l1;l3;l5;m1;m3;m5]; 
DA=det(K); 
%frÃ©quence fondamental 
for n = 1:5 F = vpasolve(DA,w,[0.4 3],'Random',true) 
end