Re: Needs[] and <<
- To: mathgroup at smc.vnet.net
- Subject: [mg23065] Re: [mg23036] Needs[] and <<
- From: Jean-Marie Thomas <jmt at agat.net>
- Date: Sat, 15 Apr 2000 03:00:24 -0400 (EDT)
- Organization: TeA
- References: <200004130643.CAA24815@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Get[] (or <<) reads a file. If the file is a package, the name of the package is added to the global variable $Packages which is the list of all loaded packages (BeginPackage does this work). Needs checks $Packages, and if the package is not present, reads the file. Then : - if you are developing a package, I suggest to use Get, implying that a new read will update modification you have done to your package code. - if the package code is frozen (i.e. you won't modify it during the session), I suggest to use Needs, meaning the file will only be read once. Needs is then useful when you call a series of packages, some of them depending on a certain package you need to declare in each package, but is only read once. jmt On Thu, 13 Apr 2000, Hans Friedrich Steffani wrote: > Why does the examples in the Mathematica book say > << Graphics`Graphics` > instead of > Needs["Graphics`Graphics`"] > ? > > Hans Friedrich Steffani > > > -- > Hans Friedrich Steffani > Institut fuer Elektrische Maschinen und Antriebe, TU Chemnitz > mailto:hans.steffani at e-technik.tu-chemnitz.de > http://www.tu-chemnitz.de/~hfst/
- References:
- Needs[] and <<
- From: hans.steffani@e-technik.tu-chemnitz.de (Hans Friedrich Steffani)
- Needs[] and <<