On-figure magnifier

Powerful on-figure magnifier, suitable for the publication of compact graphical results

Description

This utility provides a powerful zooming tool specially designed for the documentation of original and zoomed 2D graphics of images on the same plot.

It is composed of two blocks (the secondary axes and the magnifier). The secondary axes, which can be arbitrarily allocated within the limits of the figure, displays the area marked by the magnifier.

The highly versatile interface of the 'on-figure magnifier' offers a world of possibilities in a broad range of applications and fields. The Keyboard/mouse or programmatic configuration of this tool allows the user to set her or his own graphic style, to suit the requirements of any publication's editor. More details on interfacing and properties can be found in the .m file.

EXAMPLE: (for usage examples, run 'magnifyOnFigure_examples.m')
         
PROPERTIES:
       'secondaryAxesFaceColor': ColorSpec
       'edgeWidth' Color of the box surrounding the secondary
                    axes, magnifier and link. Default 1
       'edgeColor': Color of the box surrounding the secondary
                    axes, magnifier and link. Default 'black'
       'displayLinkStyle': Style of the link. 'none', 'straight' or
                    'edges', with 'straight' as default.
       'mode': 'manual' or 'interactive' (allowing
                    adjustments through mouse/keyboard). Default
                    'interactive'.
       'units' Units in which the position vectors are
                    given. Only 'pixels' currently supported
       'initialPositionSecondaryAxes': Initial position vector ([left bottom width height])
                    of secondary axes, in pixels
       'initialPositionMagnifier': Initial position vector ([left bottom width height])
                    of magnifier, in pixels
       'secondaryAxesXLim': Initial XLim value of the secondary axes
       'secondaryAxesYLim': Initial YLim value of the secondary axes

HOT KEYS (active if 'mode' set to 'interactive')

 -In a figure with multiple magnigier instances
       'Tab': Switch the focus from one magnifier instance
                    to the next one on the current figure.
       'Mouse pointer on secondary axes or magnifier of a tool+double left click'
                    Regain focus

 -On the focused magnifier instance
       'up arrow': Moves magnifier 1 pixel upwards
       'down arrow': Moves magnifier 1 pixel downwards
       'left arrow': Moves magnifier 1 pixel to the left
       'right arrow': Moves magnifier 1 pixel to the right
       'Shift+up arrow': Expands magnifier 10% on the Y-axis
       'Shift+down arrow': Compress magnifier 10% on the -axis
       'Shift+left arrow': Compress magnifier 10% on the X-axis
       'Shift+right arrow': Expands magnifier 10% on the X-axis
       'Control+up arrow': Moves secondary axes 1 pixel upwards
       'Control+down arrow': Moves secondary axes 1 pixel downwards
       'Control+left arrow': Moves secondary axes 1 pixel to the left
       'Control+right arrow': Moves secondary axes 1 pixel to the right
       'Alt+up arrow': Expands secondary axes 10% on the Y-axis
       'Alt+down arrow': Compress secondary axes 10% on the Y-axis
       'Alt+left arrow': Compress secondary axes 10% on the X-axis
       'Alt+right arrow': Expands secondary axes 10% on the X-axis
       'PageUp': Increase additional zooming factor on X-axis
       'PageDown': Decrease additional zooming factor on X-axis
       'Shift+PageUp': Increase additional zooming factor on Y-axis
       'Shift+PageDown': Decrease additional zooming factor on Y-axis
       'Control+Q': Resets the additional zooming factors to 0
       'Control+A': Displays position of secondary axes and
                    magnifier in the command window
       'Control+D': Deletes the focused tool
       'Mouse pointer on magnifier+left click' Drag magnifier to any
                    direction
       'Mouse pointer on secondary axes+left click' Drag secondary axes in any
                    direction

Acknowledgements

The author wishes to acknowledge the following in the creation of this submission:
ZoomBox, magnify, magnifyrecttofig, Jeweler's Loupe

• MATLAB release: MATLAB 7.4 (R2007a)

[Kris Gryte]

Very nice work. A few things:

(i) Hack: in order to delete the magnifier, secondary axes, and link, I simply added a new keyboard shortcut (alt+C), and then directed to a sub-function which deleted the desired axes handles and restored the figure and main axes default settings.

(ii) Problem: I have noticed the following correlation. When the figure window is small, say, 10 in x 8 in, the magnification, motion, and shortcuts work wonderfully. This changes, however, when I expand the figure window so it is maximized (i.e., roughly, 24 in by 11 in). Each time I attempt to used the magnification function on the expanded figure window, my Matlab session crashes, and if this system is able to remain responsive, I receive repetitive warnings that I have exceeded by 'listener recursion limit'. This issue is not alleviated when I reset the recursion limit to something extreme (e.g., from 500 to 10000). Hence, something within the configuration, perhaps the 'buttonmotionfcn' or some other callback which continuously updates/has eventdata, seems to find the increased window size rather disagreeable.

This stated, I was curious if you have a possible workaround for issue (ii).

(iii) Generalization: a nice, albeit more complicated, addition would be the ability to incorporate more than one plot inset for a given axes and/or figure. Possibly, by including another shortcut command, one could cycle between making a given secondary axes/magnifier active and inactive. For example, store all axes within a figure, and then upon the shortcut command, provide a 'listdlg' to allow the user to choose which axes to make active (which may or may not be a magnifier). If a magnifier axes is selected, then make the associated handles active, et cetera.

The function has outstanding functionality and use, and I am eager to have it fully and smoothly incorporated in my GUI. Thank you for this submission.

-Kris

[Kris Gryte]

Thank you for addressing the issues reported earlier. The various bug fixes, additional support, and increased functionality are greatly appreciated.

Perhaps a further generality might be the following:

- Multiple insets across multiple subplots within the same figure. I have addressed this by including another shortcut which activates the next (or previous) axes.

Thanks again.

-Kris

[David Fernandez-Prim]

Kris, thanks a lot to you too for your comments. In version 1.16, you could already switch from one inset to the next one in a figure( by pressing 'tab' of doble-clicking the inset to focus), regardless they are on the same axes or not.
Maybe this feature could already suit your needs.

I'm currently working on the performance issue, which is not an easy one. I'll let you know the status. Please don't hesitate to report any other issue/bug you might find.

- David

[Kris Gryte]

David:

Thank you for the response. Regarding switching from one inset to another, indeed, 'tab' does activate the next inset, regardless of the axes; however, the situation I envision is having say, three insets on one subplot, two insets on another subplot, three insets on yet a third subplot--for whatever reason and despite aesthetics. Maybe now the problem becomes evident. If, say, I am on the third subplot and the 8th inset, in order to access the 7th inset, I have either to (i) cycle through the other 7 insets, or (ii) use my mouse to double-click. I, personally, like shortcuts and avoid using my mouse (habit), thus, I find it more convenient to cluster my insets by axis and, for the active axes, I cycle between my 'local' insets. Further, depending on the order of placing insets on whatever axes, two insets on an axes may not be next to each other in the 'tab' order. Third, a shortcut for activating axes allows for placing insets, not necessarily even activating insets, on different axes, without mouse-clicks. And finally, I usually do most things GUI-based, in which I provide tags for each axes/inset and then provide dialogs (e.g., listboxes, etc) to allow the user to select specific axes and/or insets for manipulation. But, of course, this is my preference.

As for other notes:

(i) I like shortcuts, but, for other users, they love their mouse. Hence, an easy extension is simply to provide a 'uicontextmenu' for each created axes, in which the menu, say, for the 'magnifier' provides the various shortcuts/commands particular to that axes (resize, magnification, etc), and similarly for the inset. A user may then right-click an inset and simply select to resize or expand or whatever. And further, by listing 'Increase X-Mag (alt++)', or whatever the shortcut is, the user has a reference to remind his/herself of the various shortcuts.

(ii) Another extension may be the ability to synchronize two insets. For example, suppose I have two subplots and one inset per subplot. Further, the two subplots contain related information, and I would like to magnify a single region in both subplots. In this implementation, I have to individually drag each magnifier to the desired region separately, and then manually attempt to align the two axes. This may, or may not, be easy depending on the length of the displayed data and the resolution of the axes. A nice extension would be (yet another shortcut!) to link two insets together, such that they move in step. A similar concept has been implemented by 'Dual Cursors', which may be found on the Central File Exchange. Or, another possibility is two insets on the same axes, but separated by a given spacer. If I link them, then when I move one axis to the left by 10 units, the second axis also moves to the left exactly 10 units. Similarly for magnification, resizing, et cetera. Hence, having the ability to apply shortcuts/operations to more than one inset at a time, accomplished either using 'loops' or the 'set' function. Of course, if performance was already an issue, this suggestion would only compound matters.

Thanks again for the fixes and comments. Great work.

-Kris

[ben harper]

First of all, Thank you for your great work :)

After plotting the magnifier, if we are in interactive mode, we can change the size of magnifier and secondary axes.

Is it possible to add a key to script, when we press it it would show "final PositionSecondaryAxes" and "final PositionMagnifier"?

[David Fernandez-Prim]

Dear Ben,

The functionality you request is already available in the tool.

In interactive mode, if you hit 'control + A', you will get information about the current position of secondary axes and magnifier on the command window of MATLAB.

After that, you only need to set the properties 'PositionSecondaryAxes' and 'PositionMagnifier' to the given values on the next call to this function.

I hope this answers your request :)

[J. Caspar]

While this looks like a nice tool, I experienced problems with it due to its method of use of the figure's userdata field. It appears that the tool ignores the possibility that another application might already be using the userdata and hence when it encounters unexpected data in the field it crashes. I've always tried to treat userdata as shared space - when I read it I assume that there might be data there that I did not put there and I alway try to leave existing data unchanged when I resave to userdata. This would be a useful upgrade for this script.

[theoxarhs alex]

Everything is great, except for the fact than when semilogy is used instead of plot, the zoom box is not placed correctly on the graph. Is is misplaced a little bit lower than it should be.

Any changes to overcome this problem?
Please feel free to mail me at theoxarhs at google.com if a simple change could resolve this bug(?).
Thanks in advance.

[Corey Kelly]

This is great! Two simple questions:
1. If I wanted to change the color of the borders of the magnifier and the secondary axis, where in the code would I make the change? As is, they're showing as black, and my images are predominantly black, making them difficult to see.
2. I'm integrating the magnifier as part of a GUI, and would like to be able to toggle it on and off. It's not clear to me how to remove the magnifier once it has been initialized. Is it possible to create a handle when the magnifier starts, which can be used as an argument to a delete() call?

[David Fernandez-Prim]

Hi Corey,

1. You can easily change the color of the border of the magnifier and secondary axis through the property 'edgeColor', which by default is set to black.

2. At this moment, the tool does not provide a handle at calling time. However, there are several supported Hot Key combinations that might be useful for your purpose. 'Control+D', for instance, can be used to delete the tool from the current figure.

I hope that helps!

Regards

[suraj]

Cheers to the great work. I have a couple of questions to ask. i) How do I set the Y limits of the magnifier to match the plot area height? ii) Can I use the magnifier as a push button callback in a GUI? Thanks in advance.
Suraj

[Royi Avital]

This is Amazing!

I wish you added support for more units (The axis units would be great).

[ben harper]

hello,
i'm sorry if this feature is already added but i couldn't see.

how can i magnify on subplots?
i added between the subplots but it couldn't work.
thank you.

figure
subplot(2,1,1)
...
subplot(2,1,2)
...
magnifyonfigure
...
subplot(2,1,3)
...

[mythili]

hi..great work.....
its very useful..
thank u...

[Xuan]

 

[Jose Ercolino]

Very nice work.

[Pieter van den Berg]

 

[Tian Pan]

good

[Merc Shahraki]

Thanks alot
its very useful

[Amin]

how I can enlarge and display in a window Figure