Simultaneously numerically integrate multiple ODE's in MATLAB

1 Ansicht (letzte 30 Tage)
Rong Song
Rong Song am 5 Okt. 2019
Beantwortet: Pavel Osipov am 6 Okt. 2019
I was trying to solve a system of muptiple ODEODE at the same time in Matlab but wasn't sure how should I solve for that.
So if I have
dy1/dx=sum of yi , i from 1 to j
dy2/dx=y1^2-y2*sum of yi, i from 1 to j
dy3/dx=y1*y2+y2^2- y3*sum of yi, i from 1 to j
and given initial condition that y1(0)=1 other yi=0 (i>1)
Could anyone have me with this please? Thank you!
  2 Kommentare
Rong Song
Rong Song am 5 Okt. 2019
K=10;
% Initial Conditio
for k=1:K
if k==1
yi(k)=1;
else
yi(k)=0;
end
end
b=0;
d=20;
% y include y1 y2 y3 y4...to yK
y=zeros(1,100);
for k=1:K
if k==1
y=e(k);
dydd{k}=@(y,t) -y(k)*sum(y);
else
y=e(k);
for j=1:k-1
b=b+y(j)*y(k-j);
end
dydd{k}=@(y,t) 1/(2*y(k))*b-y(k)*sum(y);
end
end
interval=linspace(0,d,100);
[t,y]=ode45(dydd,interval,yi);

Melden Sie sich an, um zu kommentieren.

Antworten (2)

Pavel Osipov
Pavel Osipov am 5 Okt. 2019
"I was trying to solve a system of multiple orders at the same time in Matlab but wasn't sure how should I solve for that". "is that right?"
Then imagine the left part as a system of equations of the 1st order and solve in Matlab in vector form. Good luck!
  1 Kommentar
Rong Song
Rong Song am 5 Okt. 2019
Do you mean treat the y1 y2... yi as a vector ? But ode45 doesn't allow me to integrate a vector.

Melden Sie sich an, um zu kommentieren.


Pavel Osipov
Pavel Osipov am 6 Okt. 2019
ode45.PNG
odefun.PNG

Kategorien

Mehr zu Programming finden Sie in Help Center und File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by