ODE solver problem with input

I'm new to matlab so please be lenient :)

So I'm trying to solve a differential equation with the ode45 solver. The problem is the differential equation contains a function which is dependent by the differential equation itself.

I'm trying to calculate the air-density in dependence of the height. The heigth ist the solution of the differential equation.

I hope my problem is understandable.

function ypunktpunkt = Flug_DGL(t,y)
 function rohx = Dichte(y)
            if y(1) <= 11000
                T(y(1)) = 15.04-0.00649*y
                p(y(1)) = 101.29*((T(y(1))+273.1)/288.08)^5.256
    
            elseif y(1) > 11000 & y(1) <= 25000
                T(y(1)) = -56.46
                p(y(1)) = 22.65*exp(1.73-0.000157*y(1))
            else y(1) > 25000
                T(y(1)) = -131.21+0.00299*y(1)
            p(y(1)) = 2.488*((T(y(1))+273.1)/216.6)^(-11.388)
            end
    

     rohx(y(1)) = p(y(1))/(0.2896*(T(y(1))+273.1))
 end
     
u = 1500;
m_null = 10000;
m_punkt = 120;
alpa = 45;
R = 8000;
cw = 0.7;
A_front = 8;
roh=Dichte(y)
g_null = 9.81;


ypunktpunkt = [y(2) ; u*sin(alpa)*m_punkt/(m_null-m_punkt*t)-R^2*g_null/(R+y(1))^2-y(2)^2*roh*cw*A_front/2];
    
end

[t,y] = ode45('Flug_DGL',[1,300],[0;0]);
plot(t,y(:,1));

Answer 1

[Torsten]

function main
  [t,y] = ode45(@Flug_DGL,[1,300],[0;0]);
  plot(t,y(:,1));
end

function ypunktpunkt = Flug_DGL(t,y)  
  u = 1500;
  m_null = 10000;
  m_punkt = 120;
  alpa = 45;
  R = 8000;
  cw = 0.7;
  A_front = 8;
  roh = Dichte(y)
  g_null = 9.81;

  ypunktpunkt = [y(2) ; u*sind(alpa)*m_punkt/(m_null-m_punkt*t)-R^2*g_null/(R+y(1))^2-y(2)^2*roh*cw*A_front/2];
end

function rohx = Dichte(y)
  if y(1) <= 11000
    T = 15.04-0.00649*y(1);
    p = 101.29*((T+273.1)/288.08)^5.256;
  elseif y(1) > 11000 & y(1) <= 25000
    T = -56.46;
    p = 22.65*exp(1.73-0.000157*y(1));
  else y(1) > 25000
    T = -131.21+0.00299*y(1);
    p = 2.488*((T+273.1)/216.6)^(-11.388);
  end
  rohx = p/(0.2896*(T+273.1))
end