How to incorporate a push button into GUI so that data indexes from a slider are saved to an array when the push button is clicked

Hi,

I have code that plots walking kinematic data from a person that is on a treadmil. I am trying to determine when heel strike takes place and so I have plotted the lower leg using a GUI. I would now like to incorportate a push button into the code so that I can select the frames where heel strike takes place through the various gait cycles. I would like to click the marker (Heel marker) every time the person reaches heel strike and I would like the frame number to be stored in a new array so that I have a list of where heel strike took place.

My exisiting code is as follows, please help.

close all
clear all

H = ["H05"];
sH = size(H,1);
% This file uses "walking data - raw marker data.xlsx"
[filename,pathname]= uigetfile('*.mat','Select the data file');
cd(pathname);
disp('Loading data');
%all_data  = xlsread(filename,'Trial 1','A2:AS7314');
load(filename);
%[r,c] = size(all_data);

%Determine which side leg the data is collected from
SensorPosition = readtable('C:\Users\lexil\Documents\PhD\Patient_Study\CRF Trial\Healthy Participants\SensorPosition.xlsx');
for j = 1:sH   
    for i = 1:size(SensorPosition,1)
            if strcmp(cellstr(H(j)),SensorPosition{i,1}) == 1
               sensorside = SensorPosition(i,2);%issue with this line of code
            end
        end
end

% read in anthropometrics
%A = xlsread(filename,'Anthropometrics','A1:A19');

frame = trim{1,1}.frame;
time  = trim{1,1}.time;
%time  = frame * 0.01;

dt = time(2,1) - time(1,1);


yn = input('Do you want to filter the data [y/n]? ','s');
if isempty(yn)
     yn = 'y';
end

if strcmp(yn,'y') == 1
        
    %Filter the data using a butterworth 4th order filter

    fs = 1/dt; % sampling frequency
    % Ask to choose a cutoff frequency
    fc = input('Cut off frequency [8Hz]: ');
    if isempty(fc)
        %default to fc = 8Hz
        fc = 8;
    end
end
   

r = size(frame,1); 

if strcmp(sensorside{1,1},cellstr('left'))
    disp('left!');
    Toe   = trim{1,1}.LToe;
    Heel  = trim{1,1}.LHeel;
    Ankle = trim{1,1}.LAnkle;
    Knee  = trim{1,1}.LKne;
    Thigh = trim{1,1}.LThigh;
    Foot  = Toe - Heel;
    Calf = Ankle - Knee;
    UpLeg = Knee - Thigh;

elseif strcmp(sensorside{1,1},cellstr('right'))
    disp('right!');
    Toe   = trim{1,1}.RToe;
    Heel  = trim{1,1}.RHeel;
    Ankle = trim{1,1}.RAnkle;
    Knee  = trim{1,1}.RKne;
    Thigh = trim{1,1}.RThigh;
    Foot  = Toe - Heel;
    Calf = Ankle - Knee;
    UpLeg = Knee - Thigh;

else
    error('Help!');
end


f = figure;
ax = axes(f);
ax.Units = 'normalized';
ax.Position = [0.1 0.2 0.8 0.7];

a=1;
% subplot(2, 1, 1)
plot3(ax,Thigh(a,1),Thigh(a,2),Thigh(a,3),'o');
hold on
plot3(ax,Knee(a,1),Knee(a,2),Knee(a,3),'o');
plot3(ax,Ankle(a,1),Ankle(a,2),Ankle(a,3),'o');
plot3(ax,Toe(a,1),Toe(a,2),Toe(a,3),'o');
plot3(ax,Heel(a,1),Heel(a,2),Heel(a,3),'o');
axis equal
% subplot(2, 1, 2);
% plot3(Ankle(:,:));
%xlim([min(Ankle(:,1)) max(Ankle(:,1))]);
%ylim([-100 100]);
%ylim([min(Ankle(:,2)) max(Ankle(:,2))]);
%zlim([min(Ankle(:,3)) max(Ankle(:,3))]);
grid on
minx = [min(Toe(:,1)) min(Heel(:,1)) min(Ankle(:,1)) min(Knee(:,1)) min(Thigh(:,1))];
maxx = [max(Toe(:,1)) max(Heel(:,1)) max(Ankle(:,1)) max(Knee(:,1)) max(Thigh(:,1))];
xlim([min(minx) max(maxx)]);
miny = [min(Toe(:,2)) min(Heel(:,2)) min(Ankle(:,2)) min(Knee(:,2)) min(Thigh(:,2))];
maxy = [max(Toe(:,2)) max(Heel(:,2)) max(Ankle(:,2)) max(Knee(:,2)) max(Thigh(:,2))];
ylim([min(miny) max(maxy)]);
minz = [min(Toe(:,3)) min(Heel(:,3)) min(Ankle(:,3)) min(Knee(:,3)) min(Thigh(:,3))];
maxz = [max(Toe(:,3)) max(Heel(:,3)) max(Ankle(:,3)) max(Knee(:,3)) max(Thigh(:,3))];
zlim([min(minz) max(maxz)]);

Hip = Thigh; % comment out when fixed

line([Hip(a,1) Knee(a,1)],[Hip(a,2) Knee(a,2)],[Hip(a,3) Knee(a,3)],'Color','k');
line([Knee(a,1) Ankle(a,1)],[Knee(a,2) Ankle(a,2)],[Knee(a,3) Ankle(a,3)],'Color','k');
line([Ankle(a,1) Toe(a,1)],[Ankle(a,2) Toe(a,2)],[Ankle(a,3) Toe(a,3)],'Color','k');
line([Ankle(a,1) Heel(a,1)],[Ankle(a,2) Heel(a,2)],[Ankle(a,3) Heel(a,3)],'Color','k');
line([Heel(a,1) Toe(a,1)],[Heel(a,2) Toe(a,2)],[Heel(a,3) Toe(a,3)],'Color','k');



sl = uicontrol(f,'Style','slider','Min',1,'Max',r,'Sliderstep',[1/(r-1) 10/(r-1)],...
     'Callback',{@plot_leg,f,ax,Hip,Knee,Ankle,Toe, Heel});
%sl = uicontrol(f,'Style','slider','Min',1,'Max',r,'Sliderstep',[1 10],...
%    'Callback',{@plot_leg,f,ax,Hip,Knee,Ankle});
sl.Units = 'normalized';
sl.Position = [0.1 0.1 0.8 0.05];
sl.Value = a;

    

function a = plot_leg(sl,~,f,ax,Hip,Knee,Ank,Toe, Heel)

        cla(ax);
        val = get(sl,'Value')
        a = round(val);
        %Get time from slide?
        %currentIndex = round(get(src, 'Value'));

        figure(f);
        %subplot(2, 1, 1);
        plot3(ax,Hip(a,1),Hip(a,2),Hip(a,3),'o');
        hold on
        plot3(ax,Knee(a,1),Knee(a,2),Knee(a,3),'o');
        plot3(ax,Ank(a,1),Ank(a,2),Ank(a,3),'o');
        plot3(ax,Toe(a,1),Toe(a,2),Toe(a,3),'o');
        plot3(ax,Heel(a,1),Heel(a,2),Heel(a,3),'o');
        axis equal
        % Idea is to plot graph same time
        %subplot(2, 1, 2);
        %plot(r, Ankle(:,:));

        minx = [min(Toe(:,1)) min(Heel(:,1)) min(Ank(:,1)) min(Knee(:,1)) min(Hip(:,1))];
        maxx = [max(Toe(:,1)) max(Heel(:,1)) max(Ank(:,1)) max(Knee(:,1)) max(Hip(:,1))];
        xlim([min(minx) max(maxx)]);
        miny = [min(Toe(:,2)) min(Heel(:,2)) min(Ank(:,2)) min(Knee(:,2)) min(Hip(:,2))];
        maxy = [max(Toe(:,2)) max(Heel(:,2)) max(Ank(:,2)) max(Knee(:,2)) max(Hip(:,2))];
        ylim([min(miny) max(maxy)]);
        minz = [min(Toe(:,3)) min(Heel(:,3)) min(Ank(:,3)) min(Knee(:,3)) min(Hip(:,3))];
        maxz = [max(Toe(:,3)) max(Heel(:,3)) max(Ank(:,3)) max(Knee(:,3)) max(Hip(:,3))];
        zlim([min(minz) max(maxz)]);
        grid on

        % 
        line([Hip(a,1) Knee(a,1)],[Hip(a,2) Knee(a,2)],[Hip(a,3) Knee(a,3)],'Color','k');
        line([Knee(a,1) Ank(a,1)],[Knee(a,2) Ank(a,2)],[Knee(a,3) Ank(a,3)],'Color','k');
        line([Ank(a,1) Toe(a,1)],[Ank(a,2) Toe(a,2)],[Ank(a,3) Toe(a,3)],'Color','k');        
        line([Heel(a,1) Ank(a,1)],[Heel(a,2) Ank(a,2)],[Heel(a,3) Ank(a,3)],'Color','k');
        line([Heel(a,1) Toe(a,1)],[Heel(a,2) Toe(a,2)],[Heel(a,3) Toe(a,3)],'Color','k'); 
end

Answer 1

[Voss]

Create a pushbutton, after creating the slider:

btn = uicontrol(f, ...
    'Style','pushbutton', ...
    'String','Mark Heel Strike', ...
    'Units','normalized', ...
    'Position',[0.8 0.15 0.1 0.05], ...
    'Callback',{@capture_index,sl});

Its callback can be something like this:

function capture_index(src,~,sl)
idx = get(src,'UserData');
idx(end+1) = get(sl,'Value');
set(src,'UserData',idx);
end

That will store all the indices (i.e., the current slider Value when the button is pressed) in the UserData property of the button. So at any time you can get the stored indices by doing:

idx = get(btn,'UserData');

[alexandra ligeti]

Thank you so much. This works!!

If I want to store the indices as the button is pressed, is there a way for the array to be populated with values and updated with each button press and the values being stored?

At the moment I need to get the values when I feel I have collected enough HS, is there a way to store these values continuosly?

Thank you once again.

[Voss]

You're welcome!

"is there a way for the array to be populated with values and updated with each button press and the values being stored?"

Yes, that is exactly what the code does. Each time you press the button the current index is appended to the User data of the button, which contains all indices stored previously.

[alexandra ligeti]

Thank you.

I had it below a function so it was not being updated. It all works now. Thank you again for your help!

[Voss]

You're welcome!