simulation of dde problem

4 次查看（过去 30 天）

mallela ankamma rao 2022-8-9

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1776610-simulation-of-dde-problem

评论： mallela ankamma rao 2022-8-10

Good evening sir i am trying to find simulation of dde model problem but i got error. I. request you sir please help me by resolving this error

beta = 1.9;

a1 = 0.3;

a2 = 0.2;

gamma1= 0.01;

gamma2= 0.01;

gamma3= 0.05;

mu= 0.05;

tau =14;

N=1;

d1 = 0.04;

d2 = 0.02;

ddeSEIQR = @(t,y,Z)[N-beta*y(1)*y(3)/N-mu*y(1);...

(beta*y(1)*y(3)/N)-beta*exp(-mu*tau)*Z(1,1)*Z(3,1)/N-a1*y(2)-gamma1*y(2)-mu*y(2);...

beta*exp(-mu*tau)*Z(1,1)*Z(3,1)/N-a2*y(3)-gamma2*y(3)-d1*y(3)-mu*y(3);...

a1*y(2)+a2*y(3)-d2*y(4)-gamma3*y(4)-mu*y(4);...

gamma1*y(2)+gamma2*y(3)+gamma3*y(4)-mu*y(5)];

sol = dde23(ddeSEIQR,[14,1],[0.999,0,0.001,0,0],[0,200] ) ;

figure;

plot(sol.x,sol.y(1,:))

hold on

plot(sol.x,sol.y(2,:),'-')

hold on

plot(sol.x,sol.y(3,:),'--')

hold on

plot(sol.x,sol.y(4,:),'--')

hold on

plot(sol.x,sol.y(5,:),'--')

hold off

title('Equilibrium points for SEAIQR Model');

label ('time(days)');

Unrecognized function or variable 'label'.

label('solution y');

legend('S', 'E','I', 'Q','R');

ERROR:

Error using vertcat

Dimensions of arrays being concatenated are not consistent.

Error in

SEIQR_dde>@(t,y,Z)[N-beta*y(1)*y(3)/N,-mu*y(1);(beta*y(1)*y(3)/N)-beta*exp(-mu*tau)*Z(1,1)*Z(3,1)/N-a1*y(2)-gamma1*y(2)-mu*y(2);beta*exp(-mu*tau)*Z(1,1)*Z(3,1)/N-a2*y(3)-gamma2*y(3)-d1*y(3)-mu*y(3);a1*y(2)+a2*y(3)-d2*y(4)-gamma3*y(4)-mu*y(4);gamma1*y(2)+gamma2*y(3)+gamma3*y(4)-mu*y(5)]

(line 15)

ddeSEIQR = @(t,y,Z)[N- beta*y(1)*y(3)/N -mu*y(1);

Error in dde23 (line 228)

f0 = feval(ddefun,t0,y0,Z0,varargin{:});

Error in SEIQR_dde (line 21)

sol = dde23(ddeSEIQR,[14,1],[0.999,0,0.001,0,0],[0,200] ) ;

4 个评论
显示 2更早的评论隐藏 2更早的评论

Torsten 2022-8-10

what is [14,1] and how did i take ?

Did you read the documentation of dde23 ?

14 and 1 are the lags in your differential equations.

I wonder why you specified two lags because in your equations, you only refer to the first (14) with the terms

Z(1,1) (which means y1(t-14)) and

Z(3,1) (which means y3(t-14)).

mallela ankamma rao 2022-8-10

Thank you very much sir Sir this is not my model code. I want to do a paper on delay differential equations.so while i am searching for code,i got this code. Sir if you dont mind,can you refer some codes on dde models

请先登录，再进行评论。

请先登录，再回答此问题。