why do the markers change size after several key press

hi,

my code is attached below. it works but i noticed something odd. after i press '+' a few times the yellow markers shrink. it happens for the other keyboard inputs as well. why is this happening and how can i prevent it?

thanks

        function [  ] = mainClock(  )
        clear all; close all; clc; %not recommended use inside functions
        %main3  activates Draw clock function to draw the clock
        %Initialize Variables
        global toggle
        global addhour
        global addminutes
        toggle=1;
        addhour=0;
        addminutes=0;
        Figureh=0;
        Axesh=0;
        Objecth=0;
        bgcolor='r';
        %code
        Figureh=figure('NumberTitle','off','Name','Itzik Transformation Clock',...
            'Position',[200 200 500 500],'Color','r'); %bg is set to red so we know that we can only see the axes

      %Call Input Callbacks
      set(Figureh,'KeyPressFcn',@KeyboardCB);
      Objecth=DrawingCB();
      end
      function [handle] = DrawingCB()
      %initialize variables
      global toggle
      global addhour
      global addminutes
      R=3;
      x0=0;
      y0=0;
      hours=6;
      minutes=45;
      %code
      Axesh=axes('Color','c','Position',[0 0 1 1],'XTick',[],'YTick',[],'XLim',[-R R],'yLim',[-R R]);
      handle=DrawClock( Axesh,R,0,0,hours+addhour,minutes+addminutes );
      end
      function [GroupHandle] = DrawClock( h,R,x0,y0,hours,minutes )
      %DrawClock  draws a clock of radius R in axes represented by handle h
      %INPUT -
      %R - clock Radius
      %h - axis handle
      %hours - hours in 1-12 format
      %minutes - minutes 0-59 format
      %OUTPUT
      %GroupHandle - all of the clocks elements handles grouped
      %Initialize Variabls
      global toggle
      global addhour
      global addminutes
      GroupHandle=0;
      t=0:pi/18:2*pi;
      x=R*cos(t)+x0;
      y=R*sin(t)+y0;
      daspect([1 1 1]);
      %Code
      set(gcf,'CurrentAxes',h)
      %Calculate X,Y coordinates for circle Drawing using t parameter
      CircHandle=line(x,y,'Color','b','LineWidth',1,...
          'Marker','o','MarkerSize',2,'MarkerFaceColor','y','MarkerEdgeColor','y');
      %Plot circle center
      hCenter=line(x0,y0,'Marker','s','MarkerFaceColor','y','MarkerEdgeColor','y');
      %Plot Dials
      hLongDial=line([x0 x0],[y0 y0+R*0.6],'Color','r','LineWidth',3); %long dial
      hShortDial=line([x0 x0+0.3*R],[y0 y0],'Color','r','LineWidth',3); %short dial
      %calculate matrix
      Rminutes=makehgtform('zrotate',-minutes*2*pi/60);
      Rhours=makehgtform('zrotate',-hours*2*pi/12+pi/2);
      Thandleminutes = hgtransform('Parent',gca,'matrix',Rminutes);
      set(hLongDial,'Parent',Thandleminutes);
      Thandlehours = hgtransform('Parent',gca,'matrix',Rhours);
      set(hShortDial,'Parent',Thandlehours);
      end
      function [  ] = KeyboardCB(hObject,event)
      %pressing will do
      % c- toggle between minutes and hours dial
      % + - add hours/minutes
      %- -subtract hous/minutes
      global toggle
      global addhour
      global addminutes
      switch event.Key
          case 'c'
              if toggle==1
                  toggle=2;
              else
                  toggle=1;
              end
          case 'add'
              if toggle==1
                  addhour=addhour+1;
              else
                  addminutes=addminutes+1;
              end
          case 'subtract'
              if toggle==1
                  addhour=addhour-1;
              else
                  addminutes=addminutes-1;
              end
      end
       DrawingCB();
      end

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup

[Itzik Ben Shabat]

i did this. cant understand why it didnt work the first time. did it again. sorry...

Answer 1

[Itzik Ben Shabat]

so I solved the problem by adding this line of code in the main function

set(gcf, 'Renderer', 'zbuffer');

I guess there is some sort of problem with the default MATLAB renderer. Just thought to post this so whoever encounters this in the fture will know. does anyone know what the real problem is ? thanks

Answer 2

[Jan]

clear all; close all; clc; %not recommended use inside functions

What do you think does this comment mean?? Because clear all removes all breakpoints also, you cannot use the debugger to find out, what's going on. So remove this line at first. Then set some breakpoints in the function and check what happens by stepping through the code line by line. You will find, which line is responsible for the changes and if the problem does not get clear immediately, you can ask a much more precise question in the forum.

Please, Itzik, avoid this ugly piece of code also it is found in so many examples. I assume, that this brute clearing header appears such frequently in the forum, because it makes it much harder to find out by yourself, what's going on in the code.

[Itzik Ben Shabat]

Hi Jan,

First I apologize for the ugliness. i did not want to ask a general question without attaching the example.

I know what the comment means because i wrote it. I tried debugging but i stil cant unerstand whats causing this (removed the line as you said and used break points etc.).

I pasted the code just so you can use it and see the weirdness. should i attach a file in the future instead of the code?

the only new thing i noticed is that it happens after a certain amount of key presses (53 '+' from execution)

do you know whats causing this?

[Jan]

Thanks for your explanations. Posting the code with a proper formatting is fine. I cannot run Matlab currently, such that I cannot find out, which line causes the changes.