[Date Index] [Thread Index] [Author Index]

How to create a Dynamic monitoring palette that will keep working after a kernel restart?

• To: mathgroup at smc.vnet.net
• Subject: [mg124047] How to create a Dynamic monitoring palette that will keep working after a kernel restart?
• From: Szabolcs Horvát <szhorvat at gmail.com>
• Date: Sat, 7 Jan 2012 05:18:46 -0500 (EST)
• Delivered-to: l-mathgroup@mail-archive0.wolfram.com

Note: I asked this question here as well (no answers so far, but several
interesting observations):

http://stackoverflow.com/questions/8756565/creating-robust-real-time-monitors-for-variables

The problem:
------------

It easy to create a palette to monitor the value of a symbol like this:

CreatePalette@Panel@Row[{"x == ", Dynamic[x]}]

(This makes much more sense for something like e.g. $Assumptions, but
this is a simplified example.)

The problem with this approach is that if I quit the kernel by
evaluating Quit[], then restart it, then the palette will stop updating.

Question:
---------

Is there a robust way to create such monitoring palettes, that will keep
working even after a kernel restart?

Some observations:
------------------

  * If we use the Evaluation -> Quit Kernel -> Local menu item to quit,
then the palette will keep working after kernel restart

  * If we make two Dynamic cells in a new notebook / fresh kernel, like so:

Dynamic[x]
x == 1
Dynamic[x]
x == 2

Then the first one will work after kernel restart, but the second won't.

There are some more interesting observations about some possibly related
Internal` functions at

http://stackoverflow.com/questions/8756565/creating-robust-real-time-monitors-for-variables

so please be sure to check this page if you want to dig deeper.  I did
include all the essentials and my original problem as I encountered it
in this post.


--
Szabolcs Horv=E1t
Mma QA site proposal: http://area51.stackexchange.com/proposals/37304