Getting 'Reference to non-existent field' Error

I have this code I run and i cant set my button properties using the callback at the end of the script. I tried it with an another code with the same parent buttons/figures relation and it did work. Now I want to understand what is wrong with those lines and I dont seem to find it. Teach me please! It keeps on telling me Reference to non-existent field...

Thanks in advance

function [] = HandlingGUIReal()

%%BACKGROUND FIGURE

Handling.Background = figure('units','pixels',...
    'position',[200 75 800 600],...
    'menubar','none',...
    'name','Problem Example');

Handling.ClosePB = uicontrol('style','pushbutton',...
    'units','pixels',...
    'Parent',Handling.Background,...
    'position',[550 15 70 22],...
    'string','Close',...
    'callback',{@ClosePB_callback,Handling});

%%DATA PANEL

Handling.DataPanel = uipanel('units','pixels',...
    'position', [50 450 250 50],...
    'Title','Data',...
    'Parent',Handling.Background);

Handling.LoadDataPB = uicontrol('style','pushbutton',...
    'units','pixels',...
    'Parent',Handling.DataPanel,...
    'position',[31 12 69 22],...
    'string','Load Data',...
    'callback',{@LoadDataPB_callback,Handling});

%%TEMPLATE PANEL

Handling.TemplatePanel = uipanel('units','pixels',...
    'position', [50 350 250 100],...
    'Title','Template',...
    'parent',Handling.Background);

Handling.LoadTemplatePB = uicontrol('style','pushbutton',...
    'units','pixels',...
    'Parent',Handling.TemplatePanel,...
    'position',[27 15 85 23],...
    'string','Load Template',...
    'Enable', 'off');

Handling.CreateTemplatePB = uicontrol('style','pushbutton',...
    'units','pixels',...
    'Parent',Handling.TemplatePanel,...
    'position',[130 15 90 23],...
    'string','Create Template',...
    'Enable', 'off');

Handling.TemplatePUM = uicontrol('style','popupmenu',...
    'units','pixels',...
    'Parent',Handling.TemplatePanel,...
    'string','   ',...
    'position',[30 50 95 22],...
    'Enable', 'off');

function LoadDataPB_callback(varargin)
% Callback for pushbutton.
Handling = varargin{3};  % Get the structure.

Handling.DataRunFigure = figure('units','pixels',...
    'position',[120 120 750 400],...
    'name','Data Run Definition Tool');

Handling.OkPB = uicontrol('style','pushbutton',...
    'units','pixels',...
    'Parent',Handling.DataRunFigure,...
    'position',[110 25 80 22],...
    'string','OK',...
    'callback',{@OKDataPB_callback,Handling});

function OKDataPB_callback(varargin)
% Callback for pushbutton.
Handling = varargin{3};  % Get the structure.

set(Handling.LoadTemplatePB,'Enable','on')
set(Handling.CreateTemplatePB,'Enable','on')
set(Handling.TemplatePUM,'Enable','on')

close(Handling.DataRunFigure)

Answer 1

[Matt Fig]

At the time you set the callbacks, those fields did not exist in the structure. As the very last line of your main function, put:

set(Handling.ClosePB,'callback',{@ClosePB_callback,Handling})
set(Handling.LoadDataPB,'callback',{@LoadDataPB_callback,Handling})

Thus the whole structure has been created and your function can access the needed fields. Of course then you can also take out the line in the uicontrol creation where you assigned the callback, since you are doing it at the end...

[Xavier Abram]

Thanks for the fast answer Matt!

My problem (and I wasn't really clear I apologize) is not with those 2 buttons ClosePB and LoadDataPB as they do what they are supposed to do. My issue is with the OKDataPB_callback. It is supposed to make Handling.LoadTemplatePB's, CreateTemplatePB's and TemplatePUM's 'Enable' property 'on' and then close its own figure DataRunFigure. I was able to make it work in a simpler code... but I don't know why this PB doesn't do it...

[Matt Fig]

That is a strange thing to say, Xavier. The reason why it is a strange thing to say is that when you make the changes I suggest above, the code does what you say and also doesn't error any more....

[Xavier Abram]

okay, is it because when the callback is assigned to Handling.LoadDataPB the others are not created yet and thus the callback doesn't recognize the other properties to modify?

[Matt Fig]

Something like that. It is not that the callback doesn't recognize the other fields of the structure, it is just the way MATLAB works. On the line where the callback is created, S only had certain fields (the were created before that line). It is a copy of S, as it exists at the time of the assignment, that is passed to the callback.

So when you add more fields to the structure later in the code, they are not added to the copy of the structure passed to the callback earlier.

[Akhilesh Thakur]

Even I was using callbacks of Keypress function and it throwed me error that: Reference to non-existent field 'patternkeypress'. The problem here is the callback is not created yet where my program runs. So the issue here is you have to handle callbacks before your actual program runs. Like in my case I force a keypress before my program so that it never fails.

[Walter Roberson]

If the user has to undertake operations before it becomes valid to invoke a particular callback, then the callback should be disabled until it becomes valid. In the case of uicontrol 'callback' property, that means set the 'enable' property to 'disable', and then change it to 'enable' as it becomes valid to invoke. For something like a keypressfcn it might mean setting the pickableparts property off.

Or... you could have a CreateFcn callback for the GUI element that holds the keypressfcn and that CreateFcn callback can initialize appropriate variables. But be careful with this: if you are loading a .fig such as one created by GUIDE, then the handles structure does not exist until after all of the CreateFcn have been called.

Now in the case of loading a .fig such as one created by GUIDE, no user-interaction function become callable until all of the CreateFcn have run -- not unless you stuck a pause() or uiwait() or waitfor() or drawnow() inside one of the CreateFcn. So what you need to do in the case of GUIDE is to go into your *OpeningFcn and put the assignments there: the handles structure has been created by then, but the figures has not been made visible.

Answer 2

[amir aslam]

Teach me please! It keeps on telling me Reference to non-existent field...

clear; close all; clc;

addpath('lib')

testData = load('data.mat');

nnOptions = {};

modelNN = learnNN(testData.X, testData.y, nnOptions);

plotConfMat(modelNN.confusion_valid);

%% Predicting on Malware

rI = randi(size(testData.X, 1));

p = predictNN(testData.X(rI,:), modelNN);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

input_layer_size = size(X, 2);

layers = [input_layer_size, hiddenLayers, nrOfLabels];

modelNN.activationFn = activationFn;

modelNN.lambda = lambda;

modelNN.maxIter = maxIter;

modelNN.layers = layers;

modelNN.doNormalize = doNormalize;

X(isnan(X))=0;

Y = Y - min(Y) + 1;

m = size(X, 1);

validation_set_size = round(m*validPercent/100); % e.g. 10% for the validation

rand_indices = randperm(m);

X = X(rand_indices, :);

Y = Y(rand_indices);

X_valid = X(1:validation_set_size, :);

Y_valid = Y(1:validation_set_size);

X(1:validation_set_size,:) = [];

Y(1:validation_set_size) = [];

modelNN.X = X;

modelNN.Y = Y;

modelNN.X_valid = X_valid;

modelNN.Y_valid = Y_valid;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%