Any idea on why a particular line of code is not read even in the debugging mode?

I am trying to run a code. I would like that each time the pointer enters a region , it turns green..But i have been uncessful. It is the last "paragraph" of the code.

The line in question is

"set(handles.region1,'FaceColor','g'); "

function varargout = hapticpen(varargin)


% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @hapticpen_OpeningFcn, ...
                   'gui_OutputFcn',  @hapticpen_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
if nargin && ischar(varargin{1})
    gui_State.gui_Callback = str2func(varargin{1});
end

if nargout
    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
    gui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT


% --- Executes just before hapticpen is made visible.
function hapticpen_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% varargin   command line arguments to hapticpen (see VARARGIN)

% Choose default command line output for hapticpen
handles.output = hObject;
 %
 handles.region1 = [];

% % Create the Arduino serial object
%  handles.arduinoObj = serialport('COM1', 38400);
%  configureTerminator(handles.arduinoObj,'CR/LF');
% %
% for i=1:8
%     handles.message = readline(handles.arduinoObj);
%     disp(handles.message)
% end

% create_patch(handles);

% Update handles structure
guidata(hObject, handles);
% function create_patch(handles)
% if ishandle(handles.region1)
%     delete(handles.region1);
% end
    handles.region1 = patch( ...
        'Parent',handles.axes1, ...
        'XData',[5 5 20 10], ...
        'YData',[0 10 15 0], ...
        'FaceColor','red');
     set(handles.axes1,'XLim',[-10 10],'YLim',[0 10]);
     %set(handles.axes1,'XLim',[0 5],'YLim',[0 10]);
set(handles.axes1,'XGrid','on','YGrid','on');
axis(handles.axes1,'equal');
% Update handles structure
%guidata(handles.fig_hapticpen,handles);
guidata(hObject, handles);
% call the button motion fcn to update the new patch's color:
fig_hapticpen_WindowButtonMotionFcn(handles.fig_hapticpen);

% UIWAIT makes hapticpen wait for user response (see UIRESUME)
% uiwait(handles.fig_hapticpen);


% --- Outputs from this function are returned to the command line.
function varargout = hapticpen_OutputFcn(~, eventdata, handles) 
% varargout  cell array for returning output args (see VARARGOUT);
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure
varargout{1} = handles.output;


% --- Executes on mouse motion over figure - except title and menu.
function fig_hapticpen_WindowButtonMotionFcn(hObject, ~, handles)
% hObject    handle to fig_hapticpen (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
handles = guidata(hObject);
pos = get (hObject,'currentpoint');
global x;
global y;
 x = pos(1);
 y = pos(2);% assign location to x and y
set(handles.lbl_x,'string',['x loc:' num2str(x)]); %update text for x loc
set(handles.lbl_y,'string',['y loc:' num2str(y)]); %update text for x loc
% Determine if mouse is within the region

p_x = get(handles.region1,'XData');
p_x = p_x([1 2]);
p_y = get(handles.region1,'YData');
p_y = p_y([1 3]);

ax_xl = get(handles.axes1,'XLim');
ax_yl = get(handles.axes1,'YLim');

ax_units = get(handles.axes1,'Units');
if ~strcmp(ax_units,'pixels')
    set(handles.axes1,'Units','pixels')
end
ax_pos = get(handles.axes1,'Position'); % axes1 position in pixels
if ~strcmp(ax_units,'pixels')
    set(handles.axes1,'Units',ax_units);
end

% convert the patch XData and YData from axes coordinates to figure coordinates in pixels
p_x = (p_x-ax_xl(1))/(ax_xl(2)-ax_xl(1))*ax_pos(3)+ax_pos(1);
p_y = (p_y-ax_yl(1))/(ax_yl(2)-ax_yl(1))*ax_pos(4)+ax_pos(2);

if x >= p_x(1) && x <= p_x(2) && y >= p_y(1) && y <= p_y(2)
    set(handles.region1,'FaceColor','g');
  % writeline(handles.arduinoObj, '1&1!') 
else
    set(handles.region1,'FaceColor','r');
    %writeline(handles.arduinoObj, '0&1!') 
end
   guidata(hObject, handles);

[Walter Roberson]

You might need drawnow()

[Franck paulin Ludovig pehn Mayo]

@Walter Roberson where?

Answer 1

[Voss]

Checking whether x and y are each within some constant limits, like you have:

if x >= p_x(1) && x <= p_x(2) && y >= p_y(1) && y <= p_y(2)

is equivalent to checking whether the point (x,y) is within a rectangular region.

But in this case the patch is not a rectangle:

handles.axes1 = gca();
handles.region1 = patch( ...
    'Parent',handles.axes1, ...
    'XData',[5 5 20 10], ...
    'YData',[0 10 15 0], ...
    'FaceColor','red');

So you'd have to use inpolygon or equivalent to determine whether the cursor is on the patch.

Also, the rectangular region you're actually checking has zero width, because p_x(1) == p_x(2):

p_x = get(handles.region1,'XData');
p_x = p_x([1 2])

p_x = 2×1

5 5

And it extends beyond the patch in the y direction:

p_y = get(handles.region1,'YData');
p_y = p_y([1 3])

p_y = 2×1

0 15

In other words, the region you're checking is a line along the left edge of the patch that extends above the patch:

% new figure with same patch, for demonstration purposes:
figure();
handles.axes1 = gca();
handles.region1 = patch( ...
        'Parent',handles.axes1, ...
        'XData',[5 5 20 10], ...
        'YData',[0 10 15 0], ...
        'FaceColor','red');

% a line showing p_x and p_y
line(p_x,p_y,'Color','y','LineWidth',3)

So the patch will turn green only when the cursor is exactly on that yellow line (which may never actually happen, in fact).

[Franck paulin Ludovig pehn Mayo]

@Voss I am trying to put a squared shape at the right bottom corner of the Uifugre. Furthemore, X limlits and Y limit could be changed . it is not a problem.

The patch function is just making me go banana. Any help on that please?

[Voss]

The XData and YData of a patch specify the vertices of the patch, as ordered pairs (x,y), so that XData(1),YData(1) is one vertex, XData(2),YData(2) is the next vertex, and so on.

In the patch you have there:

'XData',[5 5 20 10], ...
'YData',[0 10 15 0], ...

you can read that as: start at the point (5,0), go to (5,10), then go to (20,15), then go to (10,0) (and then the patch function returns to the first point (5,0) again to complete the patch face).

So for rectangles (including squares), the vertices will always be of one of the following forms:

'XData',[x1 x1 x2 x2], ...
'YData',[y1 y2 y2 y1], ...

or:

'XData',[x1 x2 x2 x1], ...
'YData',[y1 y1 y2 y2], ...

Notice that: either the x-coordinate changes from one vertex to the next, or the y-coordinate changes from one vertex to the next, but x and y never both change at the same time. That constraint is what produces vertical and horizontal line segments.

[Franck paulin Ludovig pehn Mayo]

@Voss thank you...It is working perfectly

[Voss]

@Franck paulin Ludovig pehn Mayo You're welcome! Glad it's working now