無阻尼二自由系統固有頻率的程序

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% 無阻尼二自由系統固有頻率的程序 20180401A
' O4 q3 R/ `2 M. q0 L+ Rm1=100;m2=100;k1=200;k2=400;%
c1=0;c2=0;
% S" ?4 l4 W/ D/ U5 R' s4 _x0=[1;0];xd0=[0;0];tf=50;dt=0.1;
M=[m1,0;0,m2];k=[k1+k2,-k2;-k2,k2];
# B: D6 V  ^3 T9 Dc=[c1+c2,-c2;-c2,c2];
9 q; B. L- n0 A5 i& uA=[zeros(2,2),eye(2);-M\k,-M\c];
y0=[x0;xd0];
for i=1:round(tf/dt)+1
9 B* b$ `6 h$ v: o1 ]! m1 b    t(i)=dt*(i-1)
    y(:,i)=expm(A*t(i))*y0;
: D  S4 ^  B0 |6 _3 @, \1 p) W+ F7 Yend
subplot(2,1,1),plot(t,y(1,),grid  
$ W4 S4 g" `: X$ a4 Z' zsubplot(2,1,2),plot(t,y(2,),grid
6 B  X4 S! |: x: S2 x[p,lamda]=eig(A)
+ z- ~0 f* w1 d! o3 |: z/ W) k% \3 l


1 \) E8 B9 v7 Q* V( {
8 A4 }" S& R( @: clamda =
  Columns 1 through 2
  0.000000000000000 + 3.020447918044219i  0.000000000000000 + 0.000000000000000i
  0.000000000000000 + 0.000000000000000i  0.000000000000000 - 3.020447918044219i
  0.000000000000000 + 0.000000000000000i  0.000000000000000 + 0.000000000000000i
$ _3 @* }  }5 i0 r  0.000000000000000 + 0.000000000000000i  0.000000000000000 + 0.000000000000000i
. k% M1 {) O: d( u  Columns 3 through 4
  0.000000000000000 + 0.000000000000000i  0.000000000000000 + 0.000000000000000i
  0.000000000000000 + 0.000000000000000i  0.000000000000000 + 0.000000000000000i
-0.000000000000000 + 0.936426384924271i  0.000000000000000 + 0.000000000000000i
  0.000000000000000 + 0.000000000000000i -0.000000000000000 - 0.936426384924271i

2 `; |& y/ i* t  Q( D) N( k

' u. B& M+ s& i: K3 H7 S* [

鴻鵠重工

代碼中有個笑臉是啥意思，此處應該是什么代碼？