Why Does My Listbox Output Keep Replacing the Previous One in Matlab?

[jaclyn89]

hi, i am facing some problem when i want to display several output in a listbox.

i have a for loop to load the images from a folder, after the images loaded, it will gone through some calculation to get the average. if the images average <=10, then i want to display the images name in a listbox. when i have 5 images' average<=10, then i should display 5 images name in the list box. but now my problem is, the current output will keep replace the previous output.

anyone can help me? here is some part of my code:

sdirectory = 'D:\recognition system\database'; %specific the file directory
filess = dir([sdirectory '/*.png']);
for k = 1:length(filess)
filename = [sdirectory '\' filess(k).name];
I = imread(filename);

...
aveg(k)=abs((standev/mean1)*100);

if( aveg(k)<= 10 )


newText=sprintf('the percentage of diffrence for <<%s>> is %0.0f \n ',filename,aveg(k));
set(handles.listbox1,'String',newText);

else

set(handles.listbox1,'String','');
end
end

 

[jedishrfu]

well first question is what programming language are you using? is this matlab?

 

[jaclyn89]

yes, i am using matlab...

 

[jaclyn89]

anyone please...

 

[alphy]

One possible solution to your problem is to use the "add" function for the listbox instead of the "set" function. This will add the new output to the list instead of replacing the previous output. Your code could look something like this:

sdirectory = 'D:\recognition system\database'; %specific the file directory
filess = dir([sdirectory '/*.png']);
for k = 1:length(filess)
filename = [sdirectory '\' filess(k).name];
I = imread(filename);

...
aveg(k)=abs((standev/mean1)*100);

if( aveg(k)<= 10 )
newText=sprintf('the percentage of diffrence for <<%s>> is %0.0f \n ',filename,aveg(k));
% use "add" function to add new output to the list
add(handles.listbox1, newText);
else
% use "add" function to add blank line to list
add(handles.listbox1, '');
end
end

Alternatively, you could also store the output in a cell array and then use the "set" function to display the entire array in the listbox. This way, each new output will be added to the existing array instead of replacing it. Your code could look something like this:

sdirectory = 'D:\recognition system\database'; %specific the file directory
filess = dir([sdirectory '/*.png']);
output = {}; % initialize empty cell array
for k = 1:length(filess)
filename = [sdirectory '\' filess(k).name];
I = imread(filename);

...
aveg(k)=abs((standev/mean1)*100);

if( aveg(k)<= 10 )
newText=sprintf('the percentage of diffrence for <<%s>> is %0.0f \n ',filename,aveg(k));
% add new output to cell array
output{end+1} = newText;
else
% add blank line to cell array
output{end+1} = '';
end
end
% display entire cell array in listbox using "set" function
set(handles.listbox1, 'String', output);