Trying to get adjustment sliders to work in my code.

Its the Friedmann Equation. trying to add adjustable sliders any ideas would be helpful..

% Define the parameters

Omega_M = .31; % Assign the actual value for matter density parameter

Omega_A = .70; % Assign the actual value for dark energy density parameter

% Define the initial conditions

R0 = 1; % Initial value of R at t = t0

dRdt0 = 1; % Initial value of dR/dt at t = t0

% Define the time span for the solution

t0 = 0; % Start time

tf = 1; % End time

% Solve the system of ODEs using ode45

options = odeset('RelTol',1e-8,'AbsTol',1e-10); % Set tolerances if needed

[t, Y] = ode45(@(t, Y) cosmologyODEs(t, Y, Omega_M, Omega_A), [t0 tf], [R0; dRdt0], options);

% Extract the solution for R and dR/dt

R_solution = Y(:, 1);

dRdt_solution = Y(:, 2);

% Plot the solution for R as a function of time

plot(t, R_solution);

xlabel('Time');

ylabel('R(t)');

title('Evolution of R over time');

% Define the system of ODEs as a function

function dYdt = cosmologyODEs(t, Y, Omega_M, Omega_A)

R = Y(1);

dRdt = Y(2);

% First derivative of R

dRdt1 = dRdt;

% Second derivative of R

dRdt2 = -Omega_M/(2 * R^2) + Omega_A * R;

dYdt = [dRdt1; dRdt2];

end

Answer 1

[Ayush Modi]

Hi Kaleina,

I am assuming you are trying to add user interface control(Sliders).

You can achieve this using "uicontrol" function. Please refer to the following MathWorks documentation for more information on the “uicontrol” function:

https://www.mathworks.com/help/matlab/ref/uicontrol.html#:~:text=Option%201%27)%3B-,Create%20Slider%20Within,-Panel

Hope this helps!