How can I pass a function to the GUIDE?

Good afternoon, I am starting to use GUIDE-MATLAB, I do not have much experience, I need help I have my functions performed in SCRIP, to calculate the trajectory of a reentry vehicle to the Earth's atmosphere, I want to pass the functions to GUIDE, and I have problems with the functions, please help.

My codes.

%==========================================================================
format long
clear all
clc

%==========================================================================
%Input data
V = 8200;                   %speed at re-entry into the atmosphere MIK-1
Gca = 9500;                 %macc MIK-1 
Cxa = 1.3424;               %resistencia MIK-1
Sp = 14;                    %capsule midsection area MIK-21
K=0.4721;                   %aerodynamic coefficient MIK-1

%--------------------------------------------------------------------------
rho0 = 1.225;               %density at sea level (kg/m3)
%V = 7800;                  %speed at re-entry into the atmosphere apollo
% V = 9000;                 %speed at re-entry into the atmosphere orion
H = 100000;                 %altitude range (meters)
z=0.5;
t = 0:z:900;                %time range
% Gca = 8060;               %mass apollo
% Gca = 12000;              %mass orion
% Cxa = 1.314;              %resistance coefficient apollo
% Cxa = 1.3884;             %resistencia orion
% Sp  = 16;                 %capsule midsection area apollo
% Sp = 19.9;                %capsule midsection area orion
theta = -2;                 %angle of entry atmosphere
L=1.68;                     %rango de superficie
%K=0.5;                     %aerodynamic coefficient apollo
%K=0.5054;                  %aerodynamic coefficient orion
miu = 3.986e+14;            %gravitational parameter of the earth
beta=1.395e-04;             %atmospheric density gradient
R3= 6.371*1000000;          %earth radius
R=R3+H;
g=miu./R.^2;
Px=Gca/(Cxa*Sp);

%--------------------------------------------------------------------------
f = @(t,y) myderiv(t,y,g,Px,R3,K,rho0,beta);

%--------------------------------------------------------------------------
%Set Initial Conditions
y0(1) = V;
y0(2) = theta;
y0(3) = H;
y0(4) = L;
% y0(5)=K;%
%--------------------------------------------------------------------------
% Allocate state vector matrix and initialize first state
n = numel(t);
y = zeros(4,n);
y(:,1) = y0;

%--------------------------------------------------------------------------
%RUNGE KUTTA 4 ORDER

% z = (t(2) - t(1))/2; % stepsize
for j=1:n-1
    k1 = f(t(j)      , y(:,j)         );
    k2 = f(t(j) + z/2, y(:,j) + k1*z/2);
    k3 = f(t(j) + z/2, y(:,j) + k2*z/2);
    k4 = f(t(j) + z  , y(:,j) + k3*z  );
    y(:,j+1) = y(:,j) + (z/6)*(k1 + 2*k2 + 2*k3 + k4);
end

plot(t,y(1,:) ,'b-', 'LineWidth',2);
grid on

function dydt = myderiv(t,y,g,Px,R3,K,rho0,beta) % added rho0 and beta
V = y(1);
theta = y(2);
H = y(3);
L = y(4);
% K=y(5);%
% got rid of y(5) and y(6) which don't exist
p = rho0*exp(-H*beta);                  %atmosphere density a function of H
R = R3+H; % you need to fill this in
dVdt = -(g.*sind(theta))-(p.*(V.^2)/(2.*Px)); 
dthetadt = (p*V*K)/(2*Px)+(V^2-g*R)/(R*V)*cosd(theta); % Need V here, not v
dHdt = V*sind(theta);
dLdt = R3*V*cosd(theta)./(R);
% dn=sqrt(1+K^2)/(2*Px*g)*p*V^2;%
dydt = [dVdt;dthetadt;dHdt;dLdt];
end