Using impixelinfo command

Hi,

I used guide command to create a user interface for my matlab's code. The interface contains 2 axes: axes1 - 3D graph, axes2 - an image. I'm trying to obtain the coordinates of the graph in axes1, when the mouse is on top of it. I was told that I should use the impixelinfo command, but unfortunatly, i didn't managed how to use it.

I will be grateful for a help, Regards

Answer 1

[Walter Roberson]

Which Matlab version are you using? By 2008b at latest, the documentation for impixelinfo says,

IMPIXELINFO(H) creates a pixel information tool in the figure specified by the handle H, where H is an image, axes, uipanel, or figure object. Axes, uipanel, or figure objects must contain at least one image object.

Thus, the function would work for handles.axes2 because that axes contains an image.

To obtain coordinates within axes1 you may wish to activate datacursormode

Alternately, you may wish to set the figure WindowButtonMotionFcn property and have that callback function get() the figure CurrentPoint property and do whatever you need to do with it. If you only need the information upon clicks, use a WindowButtonDownFcn callback.

[a]

Thank you very much, you help me a lot.

The 'datacursormode' is perfect for me!!

Thanks :)

Answer 2

[Andreas Goser]

It is alwas difficult to guess -"i didn't managed how to use it." needs guessing. My guess is that IMPIXELINFO does not find your GUI automtically as the handle is hidden. I suggest using impixelinfo(h).

[a]

Thanks for your answer.

All my function got automatic parameters: hObject, eventdata, handles, As gotten from the guide command.

I tried to call the command as: impixelinfo(handles.axes1), but the matlab wrote an error message.

Whats wrong with "impixelinfo(handles.axes1)"?

Regards

[Andreas Goser]

It is important to know the error message. Error messages are there for a reason.

[a]

The error is that this function works on images only. I was told that it work on graphs too.

Are you familiar with a similar function that works on graph?

I need a function which retrieve the coordinates of the graph according to the mouse current position.

[Andreas Goser]

I'd say you need to "convert" the graph into an image.

> I was told that it work on graphs too.

Well then ask the person who told you ;-)