Azzera filtri
Azzera filtri

Ode45 returns NaN, Why?

2 visualizzazioni (ultimi 30 giorni)
Halil
Halil il 4 Apr 2018
Commentato: Halil il 5 Apr 2018
Having a system of three odes
I put the odes in a function and the script to solve the given function
I'm getting NaN for output of ode45
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function dx=funF7(t,x)
ft_to_m=0.3048;
lb_to_kg=0.45359273;
S=213.8264*ft_to_m^2;
m=22900*lb_to_kg;
CD=1.34721248450636;
CL=0.387532621392346;
phi1=0;
rho_0=1.226;
beta=0.1387/1000;
R_Earth=6378000;
%State variables
r=x(1);
V=x(2);
gamma=x(3);
h=r-R_Earth;
rho=rho_0*exp(-beta*h);
%Nonlinear equations with recpect to time
q=(V^2*rho)/2;
L=q*S*CL/m;
D=q*S*CD/m;
%Equations of motion
dx=zeros(3,1);
dx(1)=V*sin(gamma);
dx(2)=-D/cos(phi1) - sin(gamma)/r^2;
dx(3)=L/V + V*cos(gamma)/r - cos(gamma)/r^2/V;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Solver
clc; clear all
step_size1=0.0004;
r0=0.3256;
V0=2.4741;
gamma0=-0.1027;
x0=[r0 V0 gamma0];
tspan=[0 0.1];
options = odeset('MaxStep',step_size1);
[tt xx]= ode45(@funF7,tspan,x0,options);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Any help would be much appreciated. Thanks in advance!

Risposta accettata

Torsten
Torsten il 5 Apr 2018
rho = 1.226*exp(-1.387e-4*(0.3256-6378000)) ~ 1.226*exp(885) !!!
Best wishes
Torsten.
  1 Commento
Halil
Halil il 5 Apr 2018
I saw what my mistake is.
Thank you so much.

Accedi per commentare.

Più risposte (0)

Tag

Community Treasure Hunt

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

Start Hunting!

Translated by