ode45 Not enough input agruments

Hey guys,

Ive been having a problem with my code and cant seem to fix it. Every time I run my f_count.m function i receive the error message:

>> f_count(Disp_Error,10,1,0.0001)

Not enough input arguments.

Error in Disp_Error (line 8)
[t,y]=ode45(@f_freefall,[t0, t_release],Disp0,options);"

The code is:

function [result,count] = f_count(DE,t_release,dx,tol)

count=0;

while norm(dx)>tol

      t0=0;
      tf=50;
      Disp0=[0;1500;0;0];
      Dispf=[650,-6.50];
      tspan=[t0 t_release];
      options=odeset('RelTol',0.0001,'AbsTol', 0.0001);
      [~,y]=ode45(@f_freefall,tspan, Disp0,options);
      size2=y(end,:);
      tspan2=[t_release tf];
      [~,y]=ode45(@f_parachute,tspan2,size2,options);
      y=real(y);
      size3=size(y,1);
      for i=1:size3;
          if y(i,2)>=Dispf(2);
              size4(i,:)=y(1,:);
          end
      end

      t0=t_release;
      f=@Disp_Error;
      f0=f(t0);
      t0=t_release+dx;
      f=@Disp_Error;
      f1=f(t0);
      new_dt=(f1-f0)/dx(1);
      size5=new_dt'+eps;
      t_release=t_release+dx;
      size5=size5(:);

      dx=(-size5\f0 - dx);
      result=t_release;
      count=count+1;
  end
  fprintf('Count=%d\n,Result=%d\n',count,t_release)
  end

And:

function Displacement = f_freefall(t,y)

m=90;
gravity=9.81;
c1=0.27;

sx=y(1);
sy=y(2);
ux=y(3);
uy=y(4);

u=10*((sy+sx*0.01)/(1500+sx*0.01))^0.14;

ut=sqrt(((ux-u)^2)+uy^2);

ax=(-c1*(ux-u)*ut)/m;

ay=(-c1*(uy*ut))/m - gravity;
Displacement=[ux;uy;ax;ay];
end

Any help would be greatly appreciated!!!

Answer 1

[Walter Roberson]

Probably you need

f_count(@Disp_Error,10,1,0.0001)

[Rick J]

Thanks for quick response! Ive been trying that as well, but it seems to go into an infinite loop, and then output:

"Warning: Failure at t=-9.022404e+00. Unable to meet integration tolerances without reducing the step size below the smallest value allowed (2.842171e-14) at time t.

> In ode45 (line 308)

In Disp_Error (line 8)

In f_count (line 27)

Subscript indices must either be real positive integers or logicals.

Error in Disp_Error (line 20)

DispErr=Dispf-(size2(end,1:2)');

Error in f_count (line 27)

    f1=f(t0);

[Walter Roberson]

We will need to see Disp_Error