How to pre-allocate memory for 3d matrix?

Hi,

So I have a .m file which gives me 128x14 every millisecond, I am calling it and creating an object of it "h". so now i get this warning when i hove over class1, class11, class2, class22, class3, class33, class4 and class44 its asking me to preallocate memory for them, so I tried searching for the option and got this. And this is a GUI application.

class1(:,:,samples_output) = zeros(128, 14, size(x));

I place the above code under "y" but when i run it i get this error

Subscripted assignment dimension mismatch.

Error in training>start_training_Callback (line
97)
class1(:,:,samples_output) = zeros(128, 14,
size(x));

Error in gui_mainfcn (line 96)
        feval(varargin{:});

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

Error in
@(hObject,eventdata)training('start_training_Callback',hObject,eventdata,guidata(hObject))

Error while evaluating uicontrol Callback

This is the code

x = [0;1;0;-1];
y = [1;0;-1;0];

h = EmotivEEG;
h.Run;

for k = 1:samples_output

      location={};
      s=cell(1,4);
      for a = 1:4
          location{1} = sprintf('UP');
          location{2} = sprintf('RIGHT');
          location{3} = sprintf('DOWN');
          location{4} = sprintf('LEFT');
          n = location{a};
          s(a)=strread(sprintf(n),'%s','delimiter','');
      end

      set(handles.viewer_training,'YTick',[]);
      set(handles.viewer_training,'XTick',[]);
      scatter(x,y,'filled')
      text((x-.1),(y+.2),s,'color',[1,0,0]);
      hold on;  

      for s=1:size(x)
          samples_class_text = sprintf('Samples: %s \n Class: %s',num2str(k), num2str(s));
          set(handles.current_pos,'String',samples_class_text, 'FontSize', 15);
          set(handles.viewer_training,'YTick',[]);
          set(handles.viewer_training,'XTick',[]);
          scatter(x(s),y(s),400,'MarkerFaceColor',[0 0 0]);
          drawnow;
          if s == 1
              class1(:,:,s) = h.data;
              class11(:,:,s) = h.data;
              con1 = cat(3, class1(:,:,s), class11(:,:,s));
              assignin('base','class1',con1);
          elseif s == 2
              class2(:,:,s) = h.data;
              class22(:,:,s) = h.data;
              con2 = cat(3, class2(:,:,s), class22(:,:,s));
              assignin('base','class2',con2)
          elseif s == 3
              class3(:,:,s) = h.data;
              class33(:,:,s) = h.data;
              con3 = cat(3, class3(:,:,s), class33(:,:,s));
              assignin('base','class3',con3)
          elseif s == 4
              class4(:,:,s) = h.data;
              class44(:,:,s) = h.data;
              con4 = cat(3, class4(:,:,s), class44(:,:,s));
              assignin('base','class4',con4)
          end
          pause(1);
      end
      cla;
  end
  h.delete;

can anyone tell me how to preallocate the memory for those classes?

thanks in advance.

Answer 1

[Image Analyst]

h.data MUST be a 2D array - like a solid array, like an image or something. Is it? It can't be a row or column vector. It must be a 128 row by 14 column 2-D matrix or else it won't work. What does this say if you put it right after you get h but before it errors out:

whos h.data
size(h.data)
h.data