Re: Newbie
- To: mathgroup at smc.vnet.net
- Subject: [mg24493] Re: [mg24490] Newbie
- From: "Mark Harder" <harderm at ucs.orst.edu>
- Date: Thu, 20 Jul 2000 03:01:37 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Dear Want,
You describe some very strange behaviour. The correct syntax is
D[x^2,x], which on my system (WinNT v.4.0, Mathematica 4.0.1) outputs 2 x,
as expected (since Mathematica requires a second argument telling it which
symbol is variable, all others in the expression being treated as
constants).
For D[x^2] by itself and within Print[] my system outputs simply x^2. I
can't imagine how enclosing the improperly formed command within Print[]
should have any effect on the result.
The reason you get no output at all with "D[x^2];" is that following a
command with ";" suppresses output, except when the command is an output
command, like Print[], or Show[]. The semicolon is used either to suppress
output from preliminary calculations, or to separate commands in a compound
expression (several expressions taking the place of "expr" in Mathematica's
documentation). In the latter case, you *have to* use Print[] or other
explicit output commands if you want output from within the body of the
compound expression.
There are a couple of relatively short books out there for beginners. I
suggest you get one and read it, to save yourself a lot of time.
-mark e. harder
harderm at ucs.orst.edu
-----Original Message-----
From: WantToKnowPlease <replyNewsGroubPlease at eee.com>
To: mathgroup at smc.vnet.net
Subject: [mg24493] [mg24490] Newbie
>I've just started using mathematica....
>When I type a command and press (shift)+(enter) I don't see any output
>unless I preceded the command by print command
>D[x^2];(shift)+(enter) doesn't do anything !!(at least I can't see what it
>does)
>Print[D[x^2]];(shift)+(enter) prints 2 x
>
>
>any help is greatly appreciated
>
>
>
>