solving differential equations with ode 45

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Guillaume Ryelandt
评论： Ameer Hamza 2020-4-5
Hi everyone,
I have a little problem using ode45 to solve this equation with initial conditions . But every time i try to run my script, i get this message of error
Error in Ryelandt_288861_Assignment2>@(t,z)EX_3_ode(z,t,M(1),c,c3,J)
Error in odearguments (line 90)
f0 = feval(ode,t0,y0,args{:}); % ODE15I sets args{1} to yp0.
Error in ode45 (line 115)
odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);
Error in Ryelandt_288861_Assignment2 (line 33)
[t_out1,Z_out1] = ode45( @(t,z) EX_3_ode(z,t,M(1),c,c3,J), xx, IC1, opts);
Could someone help me with this ?
%% Initiate the script
clc; clear; close all
xx = linspace(0,10,1e3).';
%% Define the parameters
Ct= 200; %[J/K]
ht=140; %[W/m^2K]
At=0.02; %[m^2]
he=200; %[W/m^2K]
Ae=pi; %[m^2]
Te= 298; %[K]
V=6*pi; %[m^3]
rho=1; %[kg/m^3]
cp=4200; %[J/kgK]
J=300; %[kgm^2]
c=2; %[Nms]
c3=0.1; %[Nms^3]
cq=0.09; %[Ws^4]
M=[5,15,20,25,55]; %[Nm]
%% Question 3
%initial conditions
IC1=[0; 0];
opts= odeset('RelTol',1e-8,'AbsTol',1e-10);
[t_out1,Z_out1] = ode45( @(t,z) EX_3_ode(z,t,M(1),c,c3,J), xx, IC1, opts);
%% Function definition
function dzdt1 = EX_3_ode(z,M,c,c3,J)
dzdt1(1,1) = z(2) ;
dzdt1(2,1) =(M-c.*z(2)-c3.*z(2)^3)./J ;
end

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采纳的回答

Ameer Hamza
Ameer Hamza 2020-4-5
You need to change it like this
[t_out1,Z_out1] = ode45( @(t,z) EX_3_ode(t,z,M(1),c,c3,J), xx, IC1, opts); % first input of EX_3_ode is t
%% Function definition
function dzdt1 = EX_3_ode(t,z,M,c,c3,J) % first input should be t, if it is not used, replace it with ~
dzdt1(1,1) = z(2) ;
dzdt1(2,1) =(M-c.*z(2)-c3.*z(2)^3)./J ;
end

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