Comments on: Customizing Matlab’s Workspace table

By: Tarun Jhamnani

Tarun Jhamnani — Tue, 27 Sep 2011 10:56:07 +0000

Looking forward for the article. Will definitely re-post.
Thanks Yair.

By: Yair Altman

Yair Altman — Tue, 27 Sep 2011 10:28:13 +0000

There’s probably a way somehow to monitor variable allocation and deallocation, but I do not know how to do it. If there is any person in the world (outside MathWorks) who knows, it would probably be Andrew Janke. I plan to post an article of his about Matlab’s memory usage sometime in the hazy future, and you could re-post your question there.

By: Tarun Jhamnani

Tarun Jhamnani — Tue, 27 Sep 2011 09:27:40 +0000

Thanks Yair.
I was able to detect the variable deletion. As you have mentioned about CPU load, is there a way where deletion of particular variable can be detected (depending on memory location or something). I want to know more about variable storage in matlab environment so that I can monitor clearing of particular memory location (if it is possible).
The whole point being more efficient technique to monitor variable deletion.

By: Yair Altman

Yair Altman — Tue, 27 Sep 2011 07:58:31 +0000

@Tarun – you can try listening to the TableChanged event on the workspace table’s model:

hjModel = handle(jWSTable.getModel, 'CallbackProperties');
set(hjModel, 'TableChangedCallback', @myCallbackFunction);

Just note that this keeps firing all the time so you need to check for actual changes in the rowcount at the very top of your callback and bail-out if no change. Otherwise your Matlab will get stuck in 100% CPU load just processing the callback events…

By: Tarun Jhamnani

Tarun Jhamnani — Tue, 27 Sep 2011 05:55:19 +0000

Hi,
Works like a charm,really awesome.
My question is slightly off the track to this article.Since,it is related to workspace i will go ahead and ask. I will be glad to have input on this.
Can i monitor deletion of any variable from the workspace table(event which gets fired on deletion of variable).I tried listening events related to jworkspace table but it seems they are of no use to detect the deletion of variable.Mouseclicked,property change,key pressed etc all these event i was able to listen to.Am i missing something or i need to change my approach.
Please Help.

By: Customizing Workspace context-menu | Undocumented Matlab

Customizing Workspace context-menu | Undocumented Matlab — Wed, 03 Nov 2010 18:01:59 +0000

[...] Last week, a reader of that article posted a comment asking how to customize the context (right-click) menu with some user-defined actions [...]

By: Yair Altman

Yair Altman — Wed, 27 Oct 2010 20:54:27 +0000

@Mike – there a simple way to do this that does not directly modify the Workspace table but rather the class-registry which drives the context menu. I’ll write about this in next week’s article.

-Yair

By: Mike L

Mike L — Wed, 27 Oct 2010 20:34:55 +0000

Fantastic work! This is a really good idea. Not sure if anyone still reads this but:

I was trying to see if I could take this one step further — I have a function that allows me to preview a certain type of structure I use a lot so I thought I would try to add a new contextual menu item for this.

There appears to be two popup handlers for the Workspace browser/table, that I’m able to access using:

jWSTable.getNoSelectionPopupMenu()
jWSTable.getSelectionPopupMenu()

I’m able to change the first one easily enough; if I just call:

jWSTable.getNoSelectionPopupMenu().addSeparator()

This adds a new separator just fine. However, I can’t do the same with the more useful popup used when I have a workspace variable selected. For some reason whenever I add a new menu item to it, it gets reset after I do anything.

Would something like this require me to write a custom cell renderer as well? Or is there an easy way to do this?

By: Yair Altman

Yair Altman — Wed, 20 Jan 2010 16:42:07 +0000

@Ben – I think what you ask is possible if you add a JMI call in your CellRenderer. In a nutshell, the Renderer code will get the variable name from the table’s other column, and query its size by invoking JMI with the size function. However, this is non-trivial and also goes against known programming practices (that Renderers should be kept as light and fast as possible). On the other hand, I cannot think of any other way to do it.

By: Ben

Ben — Wed, 20 Jan 2010 16:12:18 +0000

Nice trick!

Is it possible to make the Size column display the size for 4-D matrices this way?

Right now, the Size column just displays “4-D” in case of a 4-D matrix, instead of “m x n x p x q”, which is very annoying…

Cheers,
Ben