无阻尼二自由系统固有频率的程序

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% 无阻尼二自由系统固有频率的程序 20180401A
. y2 }5 ^7 G  \m1=100;m2=100;k1=200;k2=400;%
' \" D1 T) g( `5 F- Pc1=0;c2=0;
x0=[1;0];xd0=[0;0];tf=50;dt=0.1;
/ Z) c% y) }/ ^7 \; Y. wM=[m1,0;0,m2];k=[k1+k2,-k2;-k2,k2];
c=[c1+c2,-c2;-c2,c2];
5 m5 o4 m; Y6 j# ~( |4 L' X6 j4 IA=[zeros(2,2),eye(2);-M\k,-M\c];
y0=[x0;xd0];
# C, X8 x( h$ O# g6 f" R1 ofor i=1:round(tf/dt)+1
6 ~8 h$ X8 }# v2 R+ ^  B/ X    t(i)=dt*(i-1)
4 m; B1 h/ h/ i9 r6 h& M* P9 A    y(:,i)=expm(A*t(i))*y0;
! Y) b- {$ m% nend
  g- q! A8 L$ F* E9 W9 {subplot(2,1,1),plot(t,y(1,),grid  
& \' W( h* z7 f7 b/ P( @subplot(2,1,2),plot(t,y(2,),grid
[p,lamda]=eig(A)




lamda =
2 x" C. U/ r1 W: o" j  Columns 1 through 2
# ], v" @1 U3 o) C, y( F  0.000000000000000 + 3.020447918044219i  0.000000000000000 + 0.000000000000000i
/ F4 a4 `7 w2 y9 H: K/ W" X  q  0.000000000000000 + 0.000000000000000i  0.000000000000000 - 3.020447918044219i
/ Q) U* B3 m5 n5 D/ x  0.000000000000000 + 0.000000000000000i  0.000000000000000 + 0.000000000000000i
! N2 U. n, H- g2 u" C- _; D  0.000000000000000 + 0.000000000000000i  0.000000000000000 + 0.000000000000000i
. g6 }; b$ v' k# G* v. X  Columns 3 through 4
$ y6 k+ h7 t7 O# w( H2 z  0.000000000000000 + 0.000000000000000i  0.000000000000000 + 0.000000000000000i
6 g" p! Y$ i; B; U: ^  0.000000000000000 + 0.000000000000000i  0.000000000000000 + 0.000000000000000i
-0.000000000000000 + 0.936426384924271i  0.000000000000000 + 0.000000000000000i
  0.000000000000000 + 0.000000000000000i -0.000000000000000 - 0.936426384924271i


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" Y: r) e; K. @0 I

鸿鹄重工

代码中有个笑脸是啥意思，此处应该是什么代码？