Why does Manipulate leak global symbols? (Potential bug here?)
- To: mathgroup at smc.vnet.net
- Subject: [mg123868] [mg123868] Why does Manipulate leak global symbols? (Potential bug here?)
- From: Szabolcs <szhorvat at gmail.com>
- Date: Sun, 25 Dec 2011 06:35:12 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- Reply-to: comp.soft-sys.math.mathematica at googlegroups.com
Dear MathGroup,
It appears that in Mathematica 8, using Manipulate will create some symbols in the global context. Let me illustrate:
First, I use this to monitor the contents of Global` in real time:
Dynamic@Refresh[Sort@Names["Global`*"], UpdateInterval -> 2]
Then I evaluate Manipulate[n, {n, 1, 10}]
Note that the following unexpected symbols have been added to the Global` context: BitDepth, FullScreenArea, Resolution, ScreenArea
Why does this happen? Is it a bug? Can it cause any problems (e.g. if I have defined BitDepth before using Manipulate, in the belief that there's no such builtin)?
This makes me feel a bit insecure. I am not sure if I might inadvertently break something by defining those symbols, thinking that they're not used by Mathematica (since they're syntax-coloured blue).