Sliders Not Appearing on Plot

I am working on a script for the Friedmann equation and I am trying to code a group of sliders to appear on the plot. I have a working function for the Friedmann equation plot and a separate working function for the sliders, but I am having trouble getting the sliders to appear on the figure with this resulting plot. Below is the code I am working with. I am not sure if I am missing any coding or I have some kind of error within the script that is preventing them from appearing, like a missing variable or possibly something I simply wrote incorrectly.

function friedmann

% Define figure, normalized position can be adjusted to fit individual
% monitors.
fig = figure('units','normalized',...
    'Position', [0.515 0.025 0.415 0.87],... %%%%
              'name','Friedmann');
% Define axes so that room is available in figure window for sliders
axis = axes('unit','normalized',...
          'position',[0.1 0.5 0.8 0.45]);

%%%% Actual Hubble value (m.Gyr^-1)
H0=67400/(3.09*10^(22))*(3600*24*365*10^(9));
%%%% Starting and ending time
t_begin(1) = 0.38;
t_final(1) = -15;
t_begin(2) = 0.38;
t_final(2) = 30;
%%%% Initial Omega parameters    
Omega1_m = 0.05;
Omega1_r = 10^-4;
Omega1_l = 0.95;
Omega1_k = 1-Omega1_m-Omega1_r-Omega1_l;
%%%% Initial scale factor and derivated scale factor
a1_0=1;
a1_prim_0=H0*(Omega1_m/a1_0+Omega1_r/(a1_0^2)+Omega1_k+Omega1_l*(a1_0^2))^(1/2);
init1=[ a1_0 ; a1_prim_0 ];
set(groot,'defaultLineLineWidth',1.0)
%%%% Solving in two parts : backwards and forwards
for i=1:2
 %%%% options for solver
 options = odeset('Events',@events,'RelTol',10^(-10),'AbsTol',10^(-10));
 %%%% Differential systems solving
 [t1,y1]=ode45(@(t1,y1) syseq(t1,y1,Omega1_m,Omega1_r,Omega1_l,Omega1_k),[t_begin(i) t_final(i)],init1,options);
 figure(1);
 hold on;
 %%%% Plot solutions
 plot(t1,y1(:,1),'black');
 box on;
 grid on;
 xlabel('Age');
 ylabel('Size');
 ylim([ 0 12]);
 %%%% Set label for each curve 
 posX = -13;
 posX1 = posX;
 posY1 = 3.6;
 title('Numerical Solution of the Friedmann Equation');
end
end
%%%% Differential system function
function dydt = syseq(t,y,Omega_m,Omega_r,Omega_l,Omega_k) 
%%%% Actual Hubble value
H0=67400/(3.09*10^(22))*(3600*24*365*10^(9));
dydt=[ y(2) ;
      (-(H0^(2)/2)*(Omega_m/y(1)^(3)+Omega_r/y(1)^(4)-2*Omega_l))*Omega_m*(1/(H0^(2))*y(2)^(2)-...
      Omega_r/y(1)^(2)-Omega_l*y(1)^(2)-Omega_k)^(-1);];
end
%%%% Integration stopping function
function [value,isterminal,direction] = events(t,y)
% Locate the time when height passes through zero in a
% decreasing direction and stop integration.
value = [y(1),4-y(1)]; % Detect height = 0
isterminal = [1,1];    % Stop the integration
direction = [-1,1];    % Negative and positive directions
end

function slider
% Omega variables
Omega_m = 0.05;
Omega_l = 0.95;
t_begin(1) = 0.38;

% Interval to end the function.
S.inter = 0:0.05:2;

% First Slider:
Omega_l.slider = uicontrol('style','slider',...
               'unit','normalized',...
               'position',[0.2 0.1 0.7 0.01],...
               'min',0,'max',1,'value', Omega_l,...
               'sliderstep',[0.05 0.05],...
               'callback', {@SliderCB, 'Omega1_l'}); 
% Add a text uicontrol to label the slider.
txtl = uicontrol('Style','text',...
     'unit','normalized',...
               'position',[0.2 0.11 0.7 0.02],...
     'String','Vacuum Density');
% Second Slider:
t_begin.slider = uicontrol('style','slide',...
               'unit','normalized',...
               'position',[0.2 0.15 0.7 0.01],...
               'min',-1,'max',1,'value', t_begin(1),...
               'sliderstep',[0.01 0.01],...
               'callback', {@SliderCB, 't_begin'});
% Add a text uicontrol to label the slider.
txtb = uicontrol('Style','text',...
     'unit','normalized',...
               'position',[0.2 0.16 0.7 0.02],...
     'String','Present Time, t_begin');       
% Third Slider:
Omega_m.Slider = uicontrol('style','slide',...
               'unit','normalized',...
               'position',[0.2 0.2 0.7 0.01],...
               'min',0,'max',3,'value', Omega_m,...
               'sliderstep',[0.01 0.01],...
               'callback', {@SliderCB, 'Omega1_M'});
% Add a text uicontrol to label the slider.
txtm = uicontrol('Style','text',...
     'unit','normalized',...
               'position',[0.2 0.21 0.7 0.02],...
     'String','Matter Density, Omega_M');
guidata(fig, S);  % Store S structure in the figure
end
% Callback for all sliders defined above.
function SliderCB(aSlider, EventData, Param)
S = guidata(aSlider);  % Get S structure from the figure
S.(Param) = get(aSlider, 'Value');  % Any of the 'a', 'b', etc. defined
update(S);  % Update the plot values
guidata(aSlider, S);  % Store modified S in figure
end
% Vector with new plot.
function update(S)
y = a1_prim_0(S.inter,[Omega_l,t_begin(1),Omega_m]);   % function
set(plot(t1,y1(:,1),'black'), 'YData', y);  % Replace old plot with new plotting values
end

Below is the figure that I get from running the file. The figure leaves open a space below the plot for the three sliders to fit (for the variables OmegaL, OmegaM, and tbegin), but the sliders are not appearing with the figure as I need them. What should I do or what should I add to get the sliders to appear with the plot on the figure?

Any and all help is greatly appreciated. Thank you very much in advance.

[Jonas]

withoit digging through your code, are you even calling the slider() function which creates the sliders? can't find the call in your main function

[Jordan Watts]

Thank you for your response and for pointing this out, Jonas. You are likely correct that that is the problem I am having. I am new with writing complex scripts in MATLAB, and I have not used the program often for several months, so I had forgotten I needed to call the slider() function to the main function. Just for clarification, where should I put and with what variables do I need to write the slider function within the main function? I wrote it on line 3, as

function friedmann

slider(Omega_l.aSlider, t_begin.bSlider, Omega_m.cSlider)

and it gave me this error:

Unable to resolve the name 'Omega_l.aSlider'. Error in friedmann (line 3)

slider(Omega_l.aSlider, t_begin.bSlider, Omega_m.cSlider)

Thank you again.

[Jan]

Your slider function does not have any inputs. In addition the variables Omega_m, Omega_l and t_begin are scalar constants. What is the purpose of using them a structs with the fields "aSlider", "bSlider" and "cSlider"?

[Jonas]

without knowing what are you exactly you want to do with in your gui, here is a cleaned up version which has a single update function, which pulss its parameters directly from the sliders. Since I never used ode45 or similar, you have to adjust it to make it working with sence

function friedmann
close all
% Define figure, normalized position can be adjusted to fit individual
% monitors.
fig = figure('units','normalized',...
    'Position', [0.515 0.025 0.415 0.87],... %%%%
    'name','Friedmann');
% Define axes so that room is available in figure window for sliders
ax = axes('unit','normalized',...
    'position',[0.1 0.5 0.8 0.45]);

%%%% Actual Hubble value (m.Gyr^-1)
H0=67400/(3.09*10^(22))*(3600*24*365*10^(9));
%%%% Starting and ending time
t_begin(1) = 0.38;
t_final(1) = -15;
t_begin(2) = 0.38;
t_final(2) = 30;
%%%% Initial Omega parameters
Omega1_m = 0.05;
Omega1_r = 10^-4;
Omega1_l = 0.95;
Omega1_k = 1-Omega1_m-Omega1_r-Omega1_l;


%%%% Initial scale factor and derivated scale factor
a1_0=1;
a1_prim_0=H0*(Omega1_m/a1_0+Omega1_r/(a1_0^2)+Omega1_k+Omega1_l*(a1_0^2))^(1/2);
init1=[ a1_0 ; a1_prim_0 ];
set(groot,'defaultLineLineWidth',1.0)

options = odeset('Events',@events,'RelTol',10^(-10),'AbsTol',10^(-10));
%%%% Solving in two parts : backwards and forwards
for i=1:2
    %%%% options for solver
    %%%% Differential systems solving
    [t1,y1]=ode45(@(t1,y1) syseq(t1,y1,Omega1_m,Omega1_r,Omega1_l,Omega1_k),[t_begin(i) t_final(i)],init1,options);
    figure(1);

    %%%% Plot solutions
    plotLine(i)=plot(t1,y1(:,1),'black');
    hold on;
    box on;
    grid on;
    xlabel('Age');
    ylabel('Size');
    ylim([ 0 12]);
    title('Numerical Solution of the Friedmann Equation');
end


interval = 0:0.05:2;

%% create sliders
% First Slider:
Omega_lslider = uicontrol(fig,'style','slider',...
    'unit','normalized',...
    'position',[0.2 0.1 0.7 0.01],...
    'min',0,'max',1,'value', Omega1_l,...
    'sliderstep',[0.05 0.05],...
    'callback', @update);
% Add a text uicontrol to label the slider.
txtl = uicontrol('Style','text',...
    'unit','normalized',...
    'position',[0.2 0.11 0.7 0.02],...
    'String','Vacuum Density');
% Second Slider:
t_beginslider = uicontrol('style','slide',...
    'unit','normalized',...
    'position',[0.2 0.15 0.7 0.01],...
    'min',-1,'max',1,'value', t_begin(1),...
    'sliderstep',[0.01 0.01],...
    'callback', @update);
% Add a text uicontrol to label the slider.
txtb = uicontrol('Style','text',...
    'unit','normalized',...
    'position',[0.2 0.16 0.7 0.02],...
    'String','Present Time, t_begin');
% Third Slider:
Omega_mSlider = uicontrol(fig,'style','slide',...
    'unit','normalized',...
    'position',[0.2 0.2 0.7 0.01],...
    'min',0,'max',3,'value', Omega1_m,...
    'sliderstep',[0.01 0.01],...
    'callback', @update);
% Add a text uicontrol to label the slider.
txtm = uicontrol(fig,'Style','text',...
    'unit','normalized',...
    'position',[0.2 0.21 0.7 0.02],...
    'String','Matter Density, Omega_M');


    function update(~,~)

        delete(plotLine)

        for i=1:2
            %%%% options for solver
            %%%% Differential systems solving
            [t1,y1]=ode45(@(t1,y1) syseq(t1,y1,Omega1_m,Omega1_r,Omega1_l,Omega1_k),[t_begin(i) t_final(i)],init1,options);
            %%%% Plot solutions
            plotLine(i)=plot(ax,t1,y1(:,1),'black');
        end


    end




end


%%%% Differential system function
function dydt = syseq(t,y,Omega_m,Omega_r,Omega_l,Omega_k)
%%%% Actual Hubble value
H0=67400/(3.09*10^(22))*(3600*24*365*10^(9));
dydt=[ y(2) ;
    (-(H0^(2)/2)*(Omega_m/y(1)^(3)+Omega_r/y(1)^(4)-2*Omega_l))*Omega_m*(1/(H0^(2))*y(2)^(2)-...
    Omega_r/y(1)^(2)-Omega_l*y(1)^(2)-Omega_k)^(-1);];
end
%%%% Integration stopping function
function [value,isterminal,direction] = events(t,y)
% Locate the time when height passes through zero in a
% decreasing direction and stop integration.
value = [y(1),4-y(1)]; % Detect height = 0
isterminal = [1,1];    % Stop the integration
direction = [-1,1];    % Negative and positive directions
end

[Jordan Watts]

Thank you both for your help in solving this problem.

I apologize for not having clarified further; I needed some sliders on the plot to control the OmegaM, OmegaL, and tBegin variables for the line, and with the sliders this should be feasible to solve from here. I should also be able to figure out the ODE and I assume that these will probably require similar solutions.