Axes error in GUI

I am trying to move through a series of images in a GUI but receive the following error when pressing the 'next block' button following the load button. The 'next block' button should display on the two axes on the screen the next 2 figures

{Error: Struct contents reference from a non-struct array object.

Error in Block_Sort>next_block_Callback (line 93) a1 = axes(handles.axes1);

Error in gui_mainfcn (line 95) feval(varargin{:});

Error in Block_Sort (line 42) gui_mainfcn(gui_State, varargin{:});

Error in matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)Block_Sort('next_block_Callback',hObject,eventdata,guidata(hObject)) 93 a1 = axes(handles.axes1);

} function next_block_Callback(hObject, eventdata, handles)

% hObject handle to next_block (see GCBO)

% eventdata reserved - to be defined in a future version of MATLAB

% handles structure with handles and user data (see GUIDATA)

images = guidata(hObject);

a1 = axes(handles.axes1);

a2 = axes(handles.axes2);

for i = 1:length(images)

I = images{i+1};

J = images{i+2};

imshow(a1,I);

imshow(a2,J);

end

function load_Callback(hObject, eventdata, handles)

% hObject handle to load (see GCBO)

% eventdata reserved - to be defined in a future version of MATLAB

% handles structure with handles and user data (see GUIDATA)

addpath(pwd)

animal = evalin('base','animal');

foldname = ['Selected-Figures-' animal '*'];

filename = dir(foldname);

dinfo = dir(filename.name);

addpath(filename.name);

names_cell = {dinfo.name};

names_cell = names_cell(3:end);

images = cell(1,length(names_cell));

for i = 1:length(names_cell)

    curr_file_name = names_cell{i};

    curr_im = imread(curr_file_name);

    images{i} = curr_im;

end

guidata(hObject,images);

I = imread(names_cell{1});

I = imresize(I,2);

J = imread(names_cell{2});

J = imresize(J,2);

axes(handles.axes1);

imshow(I);

axes(handles.axes2);

imshow(J);

[Geoff Hayes]

Sophie - how are you launching your GUI? From the command line, the run button in the m-file editor, or through GUIDE?

Or, are you double-clicking on the figure file? I wonder if this is the case since the error message is telling you Struct contents reference from a non-struct array object which seems to correspond to your code handles.axes1. If you open your GUI through the figure file, then this will not properly initialize your GUI and so it will be unusable. You need to launch the GUI through one of the above three methods.

[Arwinsyah Putra]

thanks ;)

it's really help

Answer 1

[OCDER]

Geoff's answer will probably resolve your initial error, but you'll probably run into issues at the same place. Note that Axes cannot return an output if used like a1 = axes(handles.axes1).

EXAMPLE:
   handles.axes1 = axes; %Creates a new axes
   a1 = axes(handles.axes1); %ERROR: Too many output arguments

If you want to draw an image in a particular axes, use the 'Parent' option like this:

imshow(I, 'parent', handles.axes1)

That way, you don't have to track which axes is the first axes, etc. Another way is to directly set the imshow's CData property.

Ix = imshow([], 'parent', handles.axes1); %initialize the imshow handle somewhere
Ix.CData = rand(100);   %change the image shown by the imshow area

[Sophie Lis]

I did it like this, but I still get the same error. I also initialize the correct way

function next_block_Callback(hObject, eventdata, handles)

images = guidata(hObject);

for i = 1:length(images)

imshow(images{i+1},'parent',handles.axes1);

imshow(images{i+2},'parent',handles.axes2);

end

[Geoff Hayes]

Sophie - how are you launching the GUI? Are you double-clicking on the figure file?

[Sophie Lis]

No, I am running it from the .m file

[Geoff Hayes]

And the error corresponds to

 mshow(images{i+1},'parent',handles.axes1);

?

Please copy and paste the full error message to this question. Also, try putting a break point at this line of code and then re-run your GUI. When the debugger pauses at this line, look at the handles variable. What can you tell us about it? (Is it a struct? Does it have a axes1 member? etc.)

[Sophie Lis]

Struct contents reference from a non-struct array object.

Error in Block_Sort>next_block_Callback (line 96)

imshow(images{i+1},'parent',handles.axes1);

Error in gui_mainfcn (line 95)

        feval(varargin{:});

Error in Block_Sort (line 42)

    gui_mainfcn(gui_State, varargin{:});

Error in

matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)Block_Sort('next_block_Callback',hObject,eventdata,guidata(hObject))

96 imshow(images{i+1},'parent',handles.axes1);

[Sophie Lis]

Handles is also very strange, it does not contain axes1 (i attached a screenshot) It looks like the handles are just the figures in the cell array images

[OCDER]

Does the OpeningFcn have the guidata(hObject, handles) line it? EX:

function myGUI_OpeningFcn(hObject, eventdata, handles, varargin)
guidata(hObject, handles);

Can you upload the full .m and .fig file so we can see what's going on?

[Sophie Lis]

Yes, it has this line. Here they are. Thank you so much!

[OCDER]

I see. The issues is when you use guidata(hObject, images), you override the GUI data that was supposed to store the handles instead.

Here's how to begin fixing it.

function load_Callback(hObject, eventdata, handles)
% hObject    handle to load (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
addpath(pwd)
animal = evalin('base','animal');
foldname = ['Selected-Figures-' animal '*'];
filename = dir(foldname);
dinfo = dir(filename.name);
addpath(filename.name);
names_cell = {dinfo.name};
names_cell = names_cell(3:end);
%%%%%images = cell(1,length(names_cell));
handles.images = cell(1,length(names_cell));
for i = 1:length(names_cell)
    curr_file_name = names_cell{i};
    curr_im = imread(curr_file_name);
    %%%%%images{i} = curr_im;
    handles.images{i} = curr_im;
end
%%%%%guidata(hObject,images); DELETE!!!! ERROR, override handles variable
guidata(hObject,handles)
I = imread(names_cell{1});
J = imread(names_cell{2});
imshow(I, 'parent', handles.axes1)
imshow(J, 'parent', handles.axes2)

So instead of trying to store images to guidata, store it as a field of handles like

handles.images = ....;
guidata(hObject, handles);

To get the images, use handles.images.

[Sophie Lis]

It works, thank you so much!!

[OCDER]

You're welcome!