MATLAB: Error “Not enough input arguments” error in Line 5

equations of motionode23

Im fairly new to Matlab and im trying to write a program that solve the 3 Degrees of Freedom Equations of Motion for an aircraft using ode23. I have the following equations
X=Ucos(Theta) (Calculates Horizontal Distance)
h=Usin(Theta) (Calculates Height)
U=(-D-mgsin(theta))/m (Calculates Speed)
theta=(-L-mgcos(theta))/(mU) (Calculates angle)
I have the following code.
Hi= 10; %Initial Height
Ui= 7.5; %Initial Speed
THi= -4; %Initial Theta
D= 10; % Drag
L= 15; % Lift
m= 40; %mass
g= 9.81; %Gravity
TSpan = [0 100]; %Time Range
[time,y] = ode23('EoM',TSpan,[0 Hi Ui THi]);
plot(time, y);
The EoM Function is
function v = EoM(D,L,m,g)
v= zeros(4,1);
v(1)=v(3)*cos(v(4)); % Distance Equation
v(2)=v(3)*sin(v(4)); % Height Equation
v(3)=(-D-(m*g*sin(v(4))))/(m); % Speed Equation
v(4)=(-L-(m*g*cos(v(4))))/(m*(v(3))); % Angle Equation
end
Im getting the following error
Not enough input arguments.
Error in EoM (line 5)
v(3)=(-D-(m*g*sin(v(4))))/(m);
Error in odearguments (line 87)
f0 = feval(ode,t0,y0,args{:});   % ODE15I sets args{1} to yp0.
Error in ode23 (line 114)
    odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);
Error in AeroEqOfMotion (line 9)
[time,y] = ode23('EoM',TSpan,[0 Hi Ui THi]);

Best Answer

Hi= 10; %Initial Height
Ui= 7.5; %Initial Speed
THi= -4; %Initial Theta
D= 10; % Drag
L= 15; % Lift
m= 40; %mass
g= 9.81; %Gravity
TSpan = [0 100]; %Time Range
[time,y] = ode23(@(t,y)EoM(t,y,D,L,m,g),TSpan,[0 Hi Ui THi]);
plot(time,y(:,1));
function dv = EoM(t,v,D,L,m,g)
dv= zeros(4,1);
dv(1)=v(3)*cos(v(4)); % Distance Equation
dv(2)=v(3)*sin(v(4)); % Height Equation
dv(3)=(-D-(m*g*sin(v(4))))/(m); % Speed Equation
dv(4)=(-L-(m*g*cos(v(4))))/(m*(v(3))); % Angle Equation
end
Best wishes
Torsten.
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