Matlab GUI Tutorial - Basic Data Processing Tool

26 Nov 2007 Quan Quach 43 comments 16,663 views

Introduction

This tutorial outlines the basic skeleton for a data processing GUI. The tutorial provides you with the visual aspect of the GUI via download, and then goes on to provide the code to each component callback. This tutorial draws upon many of the basic GUI elements: adding files to a listbox, parsing data, plotting data onto the GUI, saving GUI plots, disabling/enabling buttons, exporting data to Excel format, and many other things.

If you just want to see the finished product, you can download the source files here. The source files include the GUI files, the m-files for the sub functions, and 3 sample data files. You can play around with this GUI to learn more about how GUIs are designed and coded. You can also use this GUI as a foundation for developing more advanced GUIs. I highly encourage that you take the time to look through the source code, and to hack it to your content. Feel free to modify it so that it suits your purposes.

This tutorial is written for those with a good amount of experience creating a Matlab GUI. If you’re new to creating GUIs in Matlab, you should visit this tutorial first. Basic/Advanced knowledge of Matlab is highly recommended. Matlab version 2007a is used in writing this tutorial. Both earlier versions and new versions should be compatible as well (as long as it isan’t too outdated). Let’s get started!

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43 Responses to “Matlab GUI Tutorial - Basic Data Processing Tool”

on 16 Dec 2007 at 9:41 pm 1zuri

Hi!
Thanks for a very clear tutorial. A lot of things I’ve learnt from this tutorial. Really appreciate it.
TQ,
zuri
on 13 Jan 2008 at 8:34 pm 2Jim

I just want to say thanks a bunch!!! All your tutorials will help me and others like me gain knowledge and confidence in our jobs and lives. I’ll be sure to “pay it forward” your generosity.
on 16 Jan 2008 at 10:02 am 3jack

Hello,

I’ve been working my way through these tutorials the last few days and they are excellent - far superior to the MATLAB manual on GUIs!

A question I have regarding the current tutorial. Is there a way to change the colours of the lines in the plots - ie a different colour for each testfile that is plotted.
on 16 Jan 2008 at 10:13 am 4Quan Quach

Hello Jack,

I’m glad you found this tutorial useful.

You can change plot line colors using the following method
```
plot(x,y,'g')  %plots the data in green
```
You should check the documentation on the plot command to get more details on this.

Quan
on 16 Jan 2008 at 10:47 am 5jack

Hello Quan,

Wow what a quick reply - impressive!

Yes I have tried putting this command in. What I would like to do is have a different colour for each testfile rather than have them the same colour. In that way is it easier to identify the runs.

So TESTFILEA - Blue.
TESTFILEB - Red
TESTFILEC - Green

It is straight forward to do this in MATLAB with the raw data but it would be nice to do it in the GUI.

I have never used GUI before but following your tutorials I have gained far more information than the detailed but not very instructive MATLAB manual.
on 16 Jan 2008 at 1:15 pm 6Quan Quach

One way to do this is to define a cell array as the following:
```
colors = {'b','g','r','y'}; %you can add as many colors as necessary
```
Then, if you use a for loop to generate your plot, you can do the following:
```
for x=1:4
     plot(data{x}(:,1),data{x}(:,2), colors{x});
end
```
Not sure if this is the best way, I’ll have to get back to you on this one.
on 24 Jan 2008 at 5:19 pm 7Quan Quach

If you’re using a for loop to cycle through data that you want to plot, and you want the curves to be different colors. You should use
```
hold all
```
instead of
```
hold
```
on 27 Jan 2008 at 6:36 pm 8Kate

Hi Quan,
thanks for the help on uigetfile.
One thing that is still not working for me is that after i obtain the file path, I can’t use it. ie i save the file path as myFile, (it saves myFile as ‘C:\ etc’), but then when i try and run xlsread like this: m = xlsread(myFile, ’sheet’, ‘range’), it tells me that the filename needs to be a string. I thought it was already a string!
What am I doing wrong?

A separate unrelated question, each time i load my figure, I get the following error:

??? Error using ==> feval
Undefined command/function ‘inputFiles_edit_CreateFcn’.
Error in ==> gui_mainfcn at 75
feval(varargin{:});
Error in ==> ClassificationModelOne at 45
gui_mainfcn(gui_State, varargin{:});
??? Error using ==> struct2handle
Error while evaluating uicontrol CreateFcn

I don’t have a function called: inputFiles_edit_CreateFcn. I did at one point, but I have since removed it from the m file and from the design of the GUI. Is it hiding somewhere else that i don’t know about?
on 07 Mar 2008 at 9:21 am 9Stephen Delaney

Hi Kate,
I have been scouting forums looking for an answer to the same question you posed above (2nd question). I have an error that seems to be the exact same as the one you described above in relation to a function ‘txt_CreateFcn.’ I have been developing this GUI for a few weeks so the only thing I can imagine that happened was that I accidentally typed in that name incorrectly at some stage for a text box and deleted it just as quickly. The problem seems to be that the GUI still looks for the CreateFcn for the deleted object. I inserted a ‘txt_CreatFcn’ at the end of my m file and the error disappeared.

Hope this helps,
Best of luck with the GUI.
Steve.
on 09 Mar 2008 at 12:44 pm 10Isabel

Hello,

I’ve a problem with the function savePlotWithinGUI when I save the plot with the extension *.fig. I can save the figure without problems, but when I’m going to open it, Matlab give me the next error:
Error using ==>open
Output argument “valid” (and maybe others) not assigned during call to “C\Archivos de programa\MATLAB71\toolbox\matlab\datatypes\isprop.m (isprop)”.

If I don’t save the legend, there ins’t any problem. But I need save the figure with the legend and extension *.fig.

I hope that you can help me.

Thanks.
on 09 Mar 2008 at 12:49 pm 11Quan Quach

Hi Isabel,

I just tried to recreate your error but I couldn’t. I saved the figure WITH the legend and it was able to open up fine on it’s on. I’m sorry I cannot help you here.

Quan
on 11 Mar 2008 at 2:25 pm 12Isabel

Thanks for your answer Quan.

Can you save the plot with the legend in a file *.fig? I’m continue with the same error, I can’t use twice the function copyobj, maybe, we are working with differents version of Matlab. I’m working with matlab 7.1.

Thanks
on 11 Mar 2008 at 4:05 pm 13Quan Quach

Hi Isabel,

I’m working with version 2007a. That might be the problem

Quan
on 15 May 2008 at 11:26 am 14Nathan

Is there a way to recall the directory where the files were selected from if the working directory is elsewhere?

Thanks
on 29 May 2008 at 4:19 pm 15Brendan Owen

Thank you for this tutorial.
on 26 Jun 2008 at 12:30 pm 16Ana Molina

Thank youuuuuuuuuuuuuuuuuuuuuuuuuuuuu!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
on 26 Jun 2008 at 12:36 pm 17Ana Molina

Quan, do you know how to make a Java wrapper for a GUI and put it on the web? I’ve seen that you need the Matlab compiler for Java (https://tagteamdbserver.mathworks.com/ttserverroot/Download/47137_91126v02_MATLAB_Build_JA.pdf), but I was wondering if there’s a way without having to buy the compiler.

Thank you very much!

Ana.
on 23 Jul 2008 at 7:33 am 18Stefanus

Halo Quan Quach
Wow amazingggg, it is very helpful for me in learning GUI……..You are such generous person in sharing your knowledge with others……
Btw I still have question concerning data processing. My boss asked me to do an animation of measurement data with matlab. I do it in simple way, just write it in Mfile. To make it more interactive, I decided to make it in GUI. But there is still one element that is not exist in your explanation. In my my animation I want to make a pause button, so someone can stop the animation for a while, and can continue again after pressing the button. I would be very thankful if you could give me a hint how to do that.

Thank you very much for your kindly help

Stefanus
on 23 Aug 2008 at 10:33 pm 19Nr

Thank you for the tutorial. This example seems rather hard for me. If it is possible to publish the data process in seperate lessons again, like each .m file as a different class, it would be very nice.
on 08 Sep 2008 at 2:47 pm 20Murph1a

Quan Quach

Wonderful tutorial! I’m learning alot from you excellent code and style.
I found as I was working through the export to Excel portion of you code that the magnitude was being output to both the magnitude and phase sheets. Scratching my head, I put a breakpoint in and found two places where the code needed to be changed to get the phase numbers output. I’ve copied your code below with the corrections and noted what the change is with a comment. I suspect that you put these “errors” in to see if people were really paying attention.

for x = 1:length(fileNames)
magnitudeData = [magnitudeData data{x}(:,2)];
phaseData = [phaseData data{x}(:,3)]; % ([phaseData data{x}(:,2)];)
magDB{x} = ‘Mag (dB)’;
phaseDegrees{x} = ‘Phase(Degrees)’;
end

saveFileName = fullfile(pathname, filename);
xlswrite(saveFileName,['Data File' fileNames],’Magnitude Data’,'A1′);
xlswrite(saveFileName,['Frequency (GHz)' magDB],’Magnitude Data’,'A2′);
xlswrite(saveFileName,magnitudeData,’Magnitude Data’,'A3′);
%Was (xlswrite(saveFileName,phaseData,’Magnitude Data’,'A3′);

Intended only to help and to demonstrate that I really am learning from your Tutorial.

Thanks again,

Dave
on 10 Sep 2008 at 10:26 am 21Quan Quach

Great catch Dave! With all this code flying around I’m bound to make silly mistakes.

Quan
on 11 Sep 2008 at 6:06 am 22Rajan Sharma

ya Great job……….thanks

but can u provide me the MATLAB source code for Penrose Tiling………
its very urgent……..plz help……..
on 14 Oct 2008 at 4:59 am 23tasya

guys,

i’m using GUI matlab for my project
i’ve created 2 editbox (user input) + 1 staticbox (sum) as interface, and a ‘calculate’ button..
i wanted to write a function in ‘calculate_callback’ so that the 2 editbox will add together and give result to the ’sum_box’.

what should i write under the ‘calculate_callback’??
on 20 Oct 2008 at 2:59 pm 24Anonymous

Tasya,
you can use

val1=get(handles.edit1,’String’)
val2=get(handles.edit2,’String’)
valnum1=str2num(val1);
valnum2=str2num(val2);
total=valnum1+valnum2;
set(handles.sum,’String’,total)
on 24 Nov 2008 at 12:54 am 25San

hey,
Thank u very much for ur tutorial.its really helped me to get a knowledge about matlab.
hey I need help from u.I\\\’m University student.doing final year project(FYP) from matlab.I\\\’m going to do a \\\”Voice stress analyzer\\\” as my FYP.
I have some doubts about my matlab code.can u help me to figure it out?
take care
San
on 05 Dec 2008 at 9:49 am 26Amino

Hi Quan,

Excellent tutorial Sir .. It really opened my eyes to many hidden details.

My question: I keep getting an error mssg
“??? Cell contents assignment to a non-cell array object.”
when running a similar GUI as yours. After tracing the issue, I found that the code breaks when assiging fullfile (pathname, input_file) to inputFileNames{19} which is the evaluation of length(inputFileNames)+1 in addFiles_pushbutton_Callback function.

Summary:
code breaks here ..
“inputFileNames{length(inputFileNames)+1} = fullfile(pathname,input_file);”

Debug:
- fullfile(pathname,input_file) returns a valid location of path and file… Not the problem.
- inputFileNames = inputFiles_listbox .. No problem here either
- inputFileNames{length(inputFileNames)+1} evaluates to inputFileNames{19} .. Good to go
- inputFileNames{19} = ‘C:\path\file.ext’ … Problem!!

Any ideas why? Thanks in advance for your time.

Regards
Amino

on 05 Dec 2008 at 12:19 pm 27Quan Quach

Hi Amino,

The problem could be that when you use uigetfile, if you only select one file, it will be in the format of string. If you choose more than one file, it will be contained in a cell array.

%gets the current data file names inside the listbox
inputFileNames = get(handles.inputFiles_listbox,'String');
 
%if they only select one file, then the data will not be a cell
if iscell(input_file) == 0
 
    %add the most recent data file selected to the cell containing
    %all the data file names
    inputFileNames{length(inputFileNames)+1} = fullfile(pathname,input_file);
 
%else, data will be in cell format
else
    %stores full file path into inputFileNames
    for n = 1:length(input_file)
        inputFileNames{length(inputFileNames)+1} = fullfile(pathname,input_file{n});
    end
end

Hopefully that answers the question.

Quan

on 14 Dec 2008 at 6:32 pm 28Tayyar

Thank you for simple and useful tutorial Sir ..

Regards
Tayyar
on 18 Jan 2009 at 12:50 pm 29vasi

Hi nice program . I have a question how i can get an extra column in my txt data that i have parsed using the function parsing data. I’ve tried a lot cant figure out please help.

thanks!
on 12 Feb 2009 at 5:08 am 30Ali

hii.
i want to add two value in Edit Text
for example ( 20 60)
thank
on 05 Mar 2009 at 11:21 am 31Arthur

Hi, thanks for the great tutorial it has been very handy, however i am also trying to perform something else that i couldn’t find in any of the tutorials, wondering if you could end my sleepless nights

i am trying use a dataset called “trainIN” which i have imported into the workspace in a callback function like this
```
 
function trainbutton_Callback(hObject, eventdata, handles)
 
inputset = trainIN';
```
i need to feed it into a neural network but it is giving me an error

??? Undefined function or variable ‘trainIN’.

Error in ==> Credit_Score_Tool>trainbutton_Callback at 220
inputset = trainIN’;

Error in ==> gui_mainfcn at 96
feval(varargin{:});

Error in ==> Credit_Score_Tool at 42
gui_mainfcn(gui_State, varargin{:});

Error in ==> @(hObject,eventdata)Credit_Score_Tool(’trainbutton_Callback’,hObject,eventdata,guidata(hObject))

??? Error while evaluating uicontrol Callback

PLEEEASE HELP ME
on 12 Mar 2009 at 3:07 pm 32Zane Montgomery

Hi Arthur,
That’s a very common error one will see if you dataset isn’t available to your function. You may want to store your data set into your handles structure if you haven’t already.

Something early in your code like:
```
%Somewhere you know will run before you use 'trainbutton'
handles.trainIN= 'dataset' %the handles structure is a global variable that gets tossed around the entire GUI
... %other part of GUI
 
function trainbutton_Callback(hObject, eventdata, handles)
 
inputset = handles.trainIN;
```
If your dataset is just in your command window workspace, the GUI probably won’t be able to reference that without extra help which I’m not sure how to do.

Hopefully that’s what you’re after.
-Zane
on 13 Mar 2009 at 10:07 pm 33spc

Hi, I’m trying to use GUI in Matlab to ask user key in some value, using looping method (I need few points of coordinate x and y and hence plot the 3D graph). Is there any way to store those data in an array or matrix without replacing the values?

Thanks.
on 26 Mar 2009 at 10:05 am 34Anonymous

if i wanto display a video or a sequence of frames then can i display on the axes? and can tell me how to do it? because i’m still new to GUI programming in MATLAB
thank you
on 02 Apr 2009 at 4:26 am 35kumar

Hello!
Your matlab material is very helpful to me..
Is it possible to import data(some parameters with values) from work space in the current directory & display it on GUI (static text or if any)??
THanks & Regrads,
Swetha….
on 25 May 2009 at 10:54 pm 36Phil

Thanks for posting this tutorial. I’ve just started using MATLAB and I found this very useful indeed.
on 06 Aug 2009 at 8:46 am 37OJO

Hi, I’ll need you assistance. I Created a GUI to select an image to be displayed from a database. But I keep having problems in getting the value of the listbox uicontrol to be used by other callback functions.

function select_Callback (h_select, varargin)

% get the image of which folder to be displayed,
%folder = get (h_select, ‘Userdata’);
val = get(h_select, ‘Value’);
str = get(h_select, ‘String’);
%set (h_select, ‘Userdata’, str(val));
% set the choice as the case may be
% folder = str{val}
switch str(val);
case ‘f1′
%folder = ‘f1′;
set (h_select, ‘Value’, 1)
%set (h_select, ‘Userdata’, folder.val);
case ‘f2′
%folder = ‘f2′;
set (h_select, ‘Value’, 2)
case ‘f3′
set (h_select, ‘Value’, 3)
case ‘f4′
set (h_select, ‘Value’, 4)
case ‘f5′
set (h_select, ‘Value’, 5)
case ‘f6′
set (h_select, ‘Value’, 6)
case ‘f7′
set (h_select, ‘Value’, 7)
case ‘f8′
set (h_select, ‘Value’,
case ‘f9′
set (h_select, ‘Value’, 9)
case ‘f10′
set (h_select, ‘Value’, 10)
% set (h_select, ‘Userdata’, folder.val);
end
%set (f, ‘Userdata’, folder)
end
%————————————————————————-
function Illumination__Callback (h_illum, varargin)

% get the choice of image illumination to be displayed
val = get(h_select, ‘Value’);
str = get(h_select, ‘String’);
folder = str{val};
str = get(h_illum, ’string’);
val = get(h_illum, ‘value’);
% set the choice as the case may be
switch str{val};
case ‘Bright’
name = ‘bright’;
path = fullfile(dirloc, folder, name);
image = imread(path, ‘jpg’);
imshow (image)
case ‘Poor’
name = ‘poor’;
path = fullfile(dirloc, folder, name);
image = imread(path, ‘jpg’);
imshow (image)
case ‘Dark’
name = ‘dark’;
path = fullfile(dirloc, folder, name);
image = imread(path, ‘jpg’);
imshow (image)
end
set (f, ‘Userdata’, folder);
end

The error is
“cell contents reference from a non-cell array object.

Error in ==> fulldatabase>Illumination__Callback at 138
folder = str{val};”
on 17 Nov 2009 at 6:31 am 38Helene

It is unclear to me where to place the code for the handles that ‘enable’ and ‘disable’ the start_pushbutton. Does each handle go directly under the corresponding function? Can they be added on in one big chunk?

I’ve successfully worked through the more basic, related tutorials, but keep getting stuck at this point on basic_data_processing tool.

It’s been a while since there was a posting, but I hope someone can help. This is a great blog.

Thanks,
Helene
on 17 Nov 2009 at 4:15 pm 39Zane Montgomery

Hi Helene,

I try to troll the new posts and answer the questions that I think will help the most.

Where you put your commands matters very much. The automatically generated functions for your GUI try to be descriptive for when they get called, but aren’t always obvious. The main functions you’ll deal with/see are the _Callback and the _OpeningFcn/_CreateFcn. The latter 2 get called once your GUI first starts and builds those buttons, while the callback is the main function for whenever you button does some ‘action’ such as changing the number in an edit box, or pressing a pushbutton, or sliding the slider. Some of the functions have some commented code above them that try to describe when they get called as well (e.g. _OutputFcn).

The blinkdagger tutorials try to give good descriptions as to where the new code should go, but it’s not always obvious as to why.

Also, if you are referring to the enableButtons and disableButtons functions listed in this tutorial, note that those are specific functions made by Daniel/Quan from another tutorial that are being called in the function. You will need those functions accessible (either directly in the GUI, or in the same directory as your GUI files) to be able to use them. The code for the functions is given in Page 4 of this tutorial.

If you have any more specific questions, let us know.

GL,
Zane
on 18 Nov 2009 at 6:13 am 40Helene

Hi Zane,
Yes, the code on page 4 is precisely where I am getting stuck. I did complete that relevant tutorial with the enable and disable buttons of the 3 pushbuttons.
Under the start_pushButton_Callback, I enter ‘refresh(data_processing_tool)’ (line 13 on page 4 of this tutorial). However, in my m-file, the word ‘refresh’ does not turn BLUE as it does here. Does the word’s failure to change color mean I have the code in the wrong directory? I’d like to include the code on page 4 for these enable/disable functions directly into my basic_data_processing m file. This is what I am unsure of.

– Does every line of the code on p4 need to be entered? If so, I assume each one would be entered under the relevant component (figure1, start, reset, etc.)

– Does each “set function” then need to end with “enableButtons(handles);
guidata(hObject, handles);” ?

Thanks again. I seem to be at an incremental step in learning Matlab, and these tutorials have been great.

Helene
on 18 Nov 2009 at 8:52 am 41Zane Montgomery

Helene,

Don’t worry about the blue text from the tutorials. That is just an incomplete design for the coding language used by the website. It should NOT turn blue in your .m file.

The enableButtons/disableButtons functions can be called (almost) anywhere in your GUI .m file. If you call a function somewhere in your .m file, it searches the list of possible functions, including anywhere in the main level of your GUI. I would just copy/paste the enable/disableButtons functions to the very end of your GUI. Make sure they are separate functions by following the vertical grey line immediately to the left of your written code. You should see that a new line stops/starts for each individual function.

The big block of text/code belongs only in ’start_pushbutton_Callback’ function, not in the enable/disableButtons functions.

All of the ’set’ commands should be left alone, no need to any any code after those. Those are all self-contained within the enable/disableButtons functions.

in short:
copy/paste the block of code at the very top (on p4) into the ’start_pushbutton_Callback’ function

copy/paste the enable/disableButtons functions into the end of your GUI .m file

I admittedly haven’t gone through this whole tutorial, but let me know if any questions/errors arise.

-Zane
on 19 Nov 2009 at 4:53 am 42Helene

Success!

Many thanks. By the way, “Pimp My GUI” was hilarious - made me LOL.

Any advice on if and when to transition to building GUIs without the generous help of GUIDE?

Helene
on 19 Nov 2009 at 7:43 am 43Zane Montgomery

I still plan on using GUIDE for many years to come likely, but there are some good non-GUIDE tutorials here if you want to venture that way:

http://blogs.mathworks.com/videos/2009/08/06/gui-tutorials-from-the-file-exchange/

Include MATLAB code in your comment by doing the following:

<pre lang="MATLAB">

%insert code here

</pre>

blinkdagger