How to use data from App designer App drop downs and fields to populate variables in a script?

I have a script that there are some variables that need to be set manualy before hand that contols time and angle etc. When the script is run it askes you to select a file to load that it will proccess and spit out another set of files. I would like to be able to have a front end gui that can be compiled stand alone to run on a laptop without Matlab. This app will have a button to load the file, fields and drop downs to populate the variables in the script.

I have the basic app layout done. The Load button works and the app returns to the top of the stack of windows on the screen. I have created parameters in App Designer for all the variables in the script that need populated. I am unsure how to pass the data from the App to the script. Or do I somehow move the script to the App. Untill all variables are populated in the script the script cannot be ran correclty.

thanks for any advice

Answer 1

[Image Analyst]

You can't pass variables to a script directly. You can write a .mat file and have your script open it. But it's better to turn your script into a function. The function can be a separate m-file, or put into your app's .mlapp file.

[Donny Mott]

Hmm. That is too bad. Not very easy fix then. I have 300 lines of code in the script that I did not write. I have just modified some of it to work how I need. I am not a programmer but am trying to learn. So please bear with me.

Here is some of the start of the script.

% Source files folder

input = 'C:\TLS_Pie\';

input_file_name = uigetfile('*.pcap'); %browse to file

cd (input)

% Export folder

if (~exist('result', 'dir')); mkdir('result'); end%if

output ='result\';

% output file name

file = input_file_name;

[~,output_name,ext] = fileparts(file);

output_file_name = output_name;

%% Initialization of parameters

times = 3630; % Scan duration in tenths of a second (sec^-1)

angle = 360; % LiDAR rotation angle (-360 if cable is up)

first = 20; % Time at the first frame

I am not sure how to convert the scrip to function. I have only 10 variables that need changing. The script does not need to be seen when ran. It opens a file and proccess it then saves out a series of files. The Mat files you speak of would be a simpler option to get this going I think.

The variable input_file_name needs to come from the load button results in the app.

The times , angle, and first variables need to come from The Edit Field (numeric) box in the App. Could you show and example of one or two of these saved to a Mat file and how I would call this from the script. I think I could get it from there for the rest of them.

thanks in advacnce

[Image Analyst]

What variables might need to change from one time you call it to the next?

[Donny Mott]

The input_file_name will always change. I don't know how to handle it yet.

I made a button to run the script and added the ability to save the field box data to the settings file:

% Button pushed function: RunButton

function RunButtonPushed(app, event)

times = app.DurationEditField_2;

angle = app.AngleEditField;

first = app.DelayEditField;

alpha_1 = app.alpha1EditField;

alpha_2 = app.alpha2EditField;

gridStep = app.GridstepEditField;

R = app.offsetrEditField;

save('settings.mat','times','angle','first','gridStep','alpha_1','alpha_2','R')

TLS_PCAP

end

There is still 3 more variables that need to be changed from drop downs in the App but I don't know how to save that to the settings.mat file yet.

The field variables above do save to the mat file and they attempt to load in the script. They just do not populate the workspace or change the current variables in the script.

I use this in the script:

input = 'C:\TLS_Pie\';

disp('Contents of workspace before loading file:')

whos

disp('Contents of settings.mat:')

whos('-file','settings.mat')

load('settings.mat')

disp('Contents of workspace after loading file:')

whos

The results in the command window:

input 1x11 22 char

Contents of settings.mat:

Name Size Bytes Class Attributes

R 1x1 8 matlab.ui.control.NumericEditField

alpha_1 1x1 8 matlab.ui.control.NumericEditField

alpha_2 1x1 8 matlab.ui.control.NumericEditField

angle 1x1 8 matlab.ui.control.NumericEditField

first 1x1 8 matlab.ui.control.NumericEditField

gridStep 1x1 8 matlab.ui.control.NumericEditField

times 1x1 8 matlab.ui.control.NumericEditField

Contents of workspace after loading file:

Name Size Bytes Class Attributes

R 1x1 8 matlab.ui.control.NumericEditField

alpha_1 1x1 8 matlab.ui.control.NumericEditField

alpha_2 1x1 8 matlab.ui.control.NumericEditField

angle 1x1 8 matlab.ui.control.NumericEditField

first 1x1 8 matlab.ui.control.NumericEditField

gridStep 1x1 8 matlab.ui.control.NumericEditField

input 1x11 22 char

times 1x1 8 matlab.ui.control.NumericEditField

The do not change the Workspace or variables in the script.

I also need to re populate the fields in the app with the variables last used when it was shut down.

Lastly the script TLS_PCAP.m does not load from the Run button. It just opens another app on top of the old one.

[Image Analyst]

OK then make TLS_PCAP.m a function that looks like

function results = TLS_PCAP(fullFileName)
% Code to use fullFileName and do other stuff.

Again that can also be in your .mlapp file if you don't want it in a separate m-file.

Then whenever you want to run the script in your .mlapp code, you build fullFileName and do this:

results = TLS_PCAP(fullFileName);

[Donny Mott]

Thanks for the suggestion. I will give that a go. Any chance for some help on the other parts of the questions above?

[Image Analyst]

Donny, I don't recommend having a load button to let the user browse to their data file. Usually all the data files are in the same folder so I recommend a button to allow them to sleect a folder. Then load all the files into a listbox. That way the user can conveniently and more easily click on a file and see (plot, display) it or process it. See attached template.

[Donny Mott]

Thank you for the example. This will help alot. I see its written in Guide and not app designer.

I like your idea of loading from a folder. This was actually my end goal. Small steps first. I would like to load a series of files and have the script proccess each one at a time in order. Not sure how to do that yet.

I have all my variables working from App Designer to my script now. Including the drop downs. Making slow progress but progress.

Thank you

[Image Analyst]

Not sure why you say that. Did you double click on the .mlapp file? It brings up App Designer, not GUIDE. Isn't it like that for you?

[Donny Mott]

Yes it opens in app designer. Behind teh load folder buton was references to Guid. So I thought it may have been made in Guide.

% Button pushed function: btnSelectFolder

function btnSelectFolder_Callback(app, event)

% Create GUIDE-style callback args - Added by Migration Tool

[hObject, eventdata, handles] = convertToGUIDECallbackArguments(app, event); %#ok<ASGLU>

[Image Analyst]

Oh, it just added those because the original code was in GUIDE and it migrated it. I guess it just wnated to document that fact.