Thread Subject: How to set the position of the data cursor programmitcally

Hi

I am trying to set the position of the data cursor non-interactively.

I have two related images each having a custom data cursor function. I
am trying to link them so if the user changes the position of the data
cursor in one image, the data cursor in the other image is also
updated.

Is there a way to programmitcally send an event to the data cursor
object with the desired coordinates? Or is there a property that I can
change to achieve the same effect?

Thanks
Anup

Anup Mantri:
<SNIP wants to link his/her data cursors...

one of the solutions is outlined below
- copy the snippet into <linkcur.m>
- at the command prompt, type
     linkcur;
- move your mouse in the UPPER panel

us

function linkcur
% create the plots
     sh(1)=subplot(2,1,1);
     plot(rand(10,1));
     sh(2)=subplot(2,1,2);
     plot(rand(10,1));
% ... and the crosshair pointers
for i=1:2
     xl{i}=get(sh(i),'xlim');
     yl{i}=get(sh(i),'ylim');
     lp{i}=line([xl{i};0,0].',[0,0;yl{i}].',...
               'parent',sh(i),...
               'color',[1,0,0]);
end
     set(gcf,'windowbuttonmotionfcn',{@cb,sh,xl,yl,lp});
     shg;
end
% the callback
function cb(h,e,sh,xl,yl,lp)
     p=get(sh(1),'currentpoint');
for i=1:2
     cp=max([xl{i}(1),p(1,1)]);
     cp=min([xl{i}(2),cp]);
     set(lp{i}(2),'xdata',[cp,cp]);
     cp=max([yl{i}(1),p(1,2)]);
     cp=min([yl{i}(2),cp]);
     set(lp{i}(1),'ydata',[cp,cp]);
end
end

You can use the linkprop function to link your data cursors'
xdata/ydata/zdata properties.

A related info bit (I know this is not what you asked) that
users may find interesting is how to programmatically move
the mouse cursor (pointer). The answer is to
set(0,'PointerLocation',newPosition) or to use the moveptr
function. Note: MathWorks considers moveptr as unsupported -
it's partly documented (it has a help section, but no doc
page), but when I tried reporting some internal bugs and
fixes to MathWorks I got the "undocumented & unsupported"
shrug-off... You need to pass it handle(hAx) where hAx is
your axes handle, and it works well in simple cases
(non-complicated GUIs). moveptr.m is editable and so can
easily be adapted by anyone interested.

Yair Altman
http://ymasoftware.com

Yair Altman:
<SNIP down to - questionable - advice... in the OP's
context...

> You can use the linkprop function to link your data
cursors' xdata/ydata/zdata properties...

is that what you want?

% let's see what happens
     sh(1)=subplot(2,1,1);
           ph{1}=plot(rand(10,1));
     sh(2)=subplot(2,1,2);
           ph{2}=plot(rand(20,2));
     title('not linked');
     pause;
     title('linked');
     lp=linkprop(cat(1,ph{:}),{'xdata','ydata'});

% also, another way of controlling mous/pointer
% is shown here

% create a roboter
     import java.awt.*;
     import java.awt.event.*;
     rob=Robot;
     ss=get(0,'screensize')
     sy=fix(ss(4)/2)
for i=1:ss(3)
     rob.mouseMove(i,sy);
     pause(.01);
end

% to see more roboter options
     methods(rob);

just a few thoughts
us

On Aug 16, 2:08 pm, "us " <u...@neurol.unizh.ch> wrote:
> Yair Altman:
> <SNIP down to - questionable - advice... in the OP's
> context...
>
> > You can use the linkprop function to link your data
>
> cursors' xdata/ydata/zdata properties...
>
> is that what you want?
>
> % let's see what happens
> sh(1)=subplot(2,1,1);
> ph{1}=plot(rand(10,1));
> sh(2)=subplot(2,1,2);
> ph{2}=plot(rand(20,2));
> title('not linked');
> pause;
> title('linked');
> lp=linkprop(cat(1,ph{:}),{'xdata','ydata'});
>
> % also, another way of controlling mous/pointer
> % is shown here
>
> % create a roboter
> import java.awt.*;
> import java.awt.event.*;
> rob=Robot;
> ss=get(0,'screensize')
> sy=fix(ss(4)/2)
> for i=1:ss(3)
> rob.mouseMove(i,sy);
> pause(.01);
> end
>
> % to see more roboter options
> methods(rob);
>
> just a few thoughts
> us



Thanks us and Yair for your solutions. While not exactly what I was
looking for, I did learn a couple of new tricks :)

I should have been more specific. I am using the data cursor obtained
by executing 'datacursormode on' command to display the local pixel
info in my image. I have two of those cursors in two windows, and when
the user moves one of them, I want to update the other one too to
point to the same (x,y) coordinate.

Here is what I am trying (execute this in the command window):
figure; hp1 = plot(rand(10,1)); dcm1 = datacursormode;
figure; hp2 = plot(rand(10,1)); dcm2 = datacursormode;

Now if you click in the plot windows, you get a data tip showing the
(x,y) coordinate of the current point. The current coordinates can be
obtained by info_struct = getCursorInfo(dcm1). info_struct.Position
field contains the current position. Is there a way to update the
position of the datacursor dcm2?

Thanks

 Anup Mantri <anup.mantri@gmail.com> wrote in message
<1187381655.019037.265610@57g2000hsv.googlegroups.com>...
> I should have been more specific. I am using the data
cursor obtained
> by executing 'datacursormode on' command to display the
local pixel
> info in my image. I have two of those cursors in two
windows, and when
> the user moves one of them, I want to update the other one
too to
> point to the same (x,y) coordinate.
>
> Here is what I am trying (execute this in the command window):
> figure; hp1 = plot(rand(10,1)); dcm1 = datacursormode;
> figure; hp2 = plot(rand(10,1)); dcm2 = datacursormode;


use the following syntax to use your own data presentation
function instead of Matlab's default:

set(dcm1,'UpdateFcn',{@myDataTipFcn,dcm2}); % similarly for
dcm2

Then, within myDataTipFcn you can update the other data-cursor.

Yair Altman
http://ymasoftware.com