Error: Invalid text character. Check for unsupported symbol, invisible character, or pasting of non-ASCII characters.

clc;
close all;
clear all;
mass=[140 140 185 135 180 165 240 170 130 160 118 148 140 150 115 130 ]; % lbs
for part=1:16 %participants
    for c=1:4 %conditions: squat vs stoop and close vs far
        
        clear markers shoulder elbow wrist L5/S1 object
        if c==1
            cond='_squat_close';
        else if c==2
                cond='_squat_far';
        else if c==3
                cond='_stoop_close';
        else
            cond='_stoop_far';
        end
        end
        end
        mass1(part)=mass(part)*4.44822; % to newtons
        filename=['P' num2str(part),cond]; % reads in files
        load([filename, '.mat']);
        trial=['P' num2str(part), cond];
        condition=[cond, num2str(part)];
        
        Markers=eval([condition, '.Trajectories.Labeled.Data'])./1000;
        markernames=eval([condition, '.Trajectories.Labeled.Labels']);
        markernames(5)={'L5S1'};
        
        Markers=permute(Markers,[3,1,2]);
        Markers=Markers(:,:,1:3);
        num_marks=length(markernames); % dynamically assess number of markers
        
        fs.video=eval([condition, '.FrameRate']); % extract sampling frequency of camera system
        
        [butter_b,butter_a] = butter(4,2*10/fs.video); % Video at 10 Hz
        for i = 1:3 
            Markers(:,1:num_marks,i) = filtfilt(butter_b,butter_a,Markers(:,1:num_marks,i));
        end
        clear markers
        % Name Markers 
        for p = 1:num_marks
            eval(['markers.', markernames{p} '= squeeze(Markers(:,p,1:3));']);
            %                 eval(['markers.', markernames{pa} '= squeeze(Markers(:,pa,1:3));']);
        end; clear Markers
        
        
        
        
        percent_initial = (0:1/fs.video:(size(markers.shoulder(:,1))-1)/fs.video);
        percent_initial = (percent_initial/percent_initial(end))*100;
        percent_final = (0:100);
        
        markers.r_shoulder=markers.r_shoulder';
        markers.l_shoulder=markers.l_shoulder';
        markers.elbow=markers.elbow';
        markers.wrist=markers.wrist';
        markers.L5S1=markers.L5S1';
        markers.object=markers.object';
        
        normalized_marker_r_shoulder=interp1(percent_initial, markers.r_shoulder(1,:), percent_final);
        normalized_marker_l_shoulder=interp1(percent_initial, markers.l_shoulder(1,:), percent_final);
        normalized_marker_elbow=interp1(percent_initial, markers.elbow(1,:), percent_final);
        normalized_marker_wrist=interp1(percent_initial, markers.wrist(1,:), percent_final);
        normalized_marker_l5S1=interp1(percent_initial, markers.L5S1(1,:), percent_final);
        normalized_marker_object=interp1(percent_initial, markers.object(1,:), percent_final);
        
        xlswrite('data4.xlsx', mass1(part), [num2str(part)], 'KK3');
        if c==1
            xlswrite('data4.xlsx', normalized_marker_r_shoulder', [num2str(part)], 'B3');
            xlswrite('data4.xlsx', normalized_marker_l_shoulder', [num2str(part)], 'C3');
            xlswrite('data4.xlsx', normalized_marker_elbow', [num2str(part)], 'D3');
            xlswrite('data4.xlsx', normalized_marker_wrist', [num2str(part)], 'E3');
            xlswrite('data4.xlsx', normalized_marker_l5S1', [num2str(part)], 'A3');
            xlswrite('data4.xlsx', normalized_marker_object', [num2str(part)], 'F3');
        else if c==2
                xlswrite('data4.xlsx', normalized_marker_r_shoulder', [num2str(part)], 'L3');
                xlswrite('data4.xlsx', normalized_marker_l_shoulder', [num2str(part)], 'M3');
                xlswrite('data4.xlsx', normalized_marker_elbow', [num2str(part)], 'N3');
                xlswrite('data4.xlsx', normalized_marker_wrist', [num2str(part)], 'O3');
                xlswrite('data4.xlsx', normalized_marker_l5S1', [num2str(part)], 'K3');
                xlswrite('data4.xlsx', normalized_marker_object', [num2str(part)], 'P3');
        else if c==3
                xlswrite('data4.xlsx', normalized_marker_r_shoulder', [num2str(part)], 'V3');
                xlswrite('data4.xlsx', normalized_marker_l_shoulder', [num2str(part)], 'W3');
                xlswrite('data4.xlsx', normalized_marker_elbow', [num2str(part)], 'X3');
                xlswrite('data4.xlsx', normalized_marker_wrist', [num2str(part)], 'Y3');
                xlswrite('data4.xlsx', normalized_marker_l5S1', [num2str(part)], 'U3');
                xlswrite('data4.xlsx', normalized_marker_object', [num2str(part)], 'Z3');
        else
            xlswrite('data4.xlsx', normalized_marker_r_shoulder', [num2str(part)], 'FF3');
            xlswrite('data4.xlsx', normalized_marker_l_shoulder', [num2str(part)], 'GG3');
            xlswrite('data4.xlsx', normalized_marker_elbow', [num2str(part)], 'HH3');
            xlswrite('data4.xlsx', normalized_marker_wrist', [num2str(part)], 'II3');
            xlswrite('data4.xlsx', normalized_marker_l5S1', [num2str(part)], 'EE3');
            xlswrite('data4.xlsx', normalized_marker_object', [num2str(part)], 'JJ3');
        end
        
        end
        end
    end
end

Error using load
Unable to find file or directory 'P1_squat_close.mat'.

[James Tursa]

Which line has the error? Simply examine all the characters on that line.

[Walter Roberson]

Please read http://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval for information about why we strongly recommend against creating variable names dynamically.

[Josh Riesenberg]

When I click "Run" I get a pop up box that says "syntax error: Data_Collection_4 cannot run as it appears"

Data_Collection_4

[Walter Roberson]

@Josh Riesenberg

Please attach the actual file Data_Collection_4.m -- not just copy-and-paste but attach, so that we will get an exact copy of the contents.

[Josh Riesenberg]

Here is the file

[Walter Roberson]

My system does not find any invalid characters for it.

There are a number of improvements suggested, such as changing xlswrite to writetable() or writematrix(), or changing the

else if CONDITION

to

elseif CONDITION

or getting rid of the eval() --- but no complaints about invalid characters

[Josh Riesenberg]

I have been retyping the program out and it will run without that syntax error until I get to the following 3 lines:

Markers=eval([condition, '.Trajectories.Labeled.Data'])./1000;

markernames=eval([condition, '.Trajectories.Labeled.Labels']);

markernames(5)={'L5S1'};

If those are commented out, the program will run without the syntax error, but if even one of the is uncommented, it gives the syntax error

[Walter Roberson]

@Josh Riesenberg

You ran into a problem using eval() when you tried to dynamically generate variable names. Now start to get an idea why we have been telling you that you should not dynamically generate variable names.

After you have done

filename=['P' num2str(part),cond]; % reads in files

please show us the output of

whos('-file', filename)

Answer 1

[Dheeraj]

Hi,

It is a good practice to generate variable names at the compile time as generating them at the run time is not advised as it creates untraceable bugs. You could refer to this link for better understanding.

http://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval