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
& Q$ o5 ^0 J0 |1 y7 c1 Q, km1=100;m2=100;k1=200;k2=400;%
3 t. S) g& ?: \0 G* w3 P# ~$ Ec1=0;c2=0;
x0=[1;0];xd0=[0;0];tf=50;dt=0.1;
M=[m1,0;0,m2];k=[k1+k2,-k2;-k2,k2];
c=[c1+c2,-c2;-c2,c2];
A=[zeros(2,2),eye(2);-M\k,-M\c];
) U9 {6 n! w4 d9 K, n4 z& Py0=[x0;xd0];
for i=1:round(tf/dt)+1
    t(i)=dt*(i-1)
    y(:,i)=expm(A*t(i))*y0;
$ z* B( a: ]* p. g, [+ v: Tend
subplot(2,1,1),plot(t,y(1,),grid  
subplot(2,1,2),plot(t,y(2,),grid
2 [% y- R  E& l[p,lamda]=eig(A)



. j, ]( i& Y9 l' W( k# D' O5 {
lamda =
$ e( R3 K- A, H! q  Columns 1 through 2
$ U3 g6 `& h4 F" n  0.000000000000000 + 3.020447918044219i  0.000000000000000 + 0.000000000000000i
! E/ K- q' i. @( X9 d  0.000000000000000 + 0.000000000000000i  0.000000000000000 - 3.020447918044219i
) d0 G( p, g+ h' k' {2 M( Q  0.000000000000000 + 0.000000000000000i  0.000000000000000 + 0.000000000000000i
  0.000000000000000 + 0.000000000000000i  0.000000000000000 + 0.000000000000000i
  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



! e8 E7 _& Z9 l) q0 u' Q$ _" _2 b
( @  n9 w& }! m3 j4 b  D

鴻鵠重工

代碼中有個笑臉是啥意思，此處應該是什么代碼？