Re: Why doesn't this work ?
- To: mathgroup@smc.vnet.net
- Subject: [mg10436] Re: [mg10381] Why doesn't this work ?
- From: Wouter Meeussen <eu000949@pophost.eunet.be>
- Date: Tue, 13 Jan 1998 02:07:34 -0500
Andreas,
it is the Plot[ ] that needs a in-place Evaluate command: (see help file
:
"Plot evaluates its arguments in a nonstandard way (see
SectionA.4.). You
should use Evaluate to evaluate the function to be plotted if this can
safely
be done before specific numerical values are supplied. ")
In[7]:Clear[S2];
S2¼in[x],Cos[x]};
Plot[Evaluate@S2, {x, 0, Pi}]
In[12]:Clear[S,dx,S3,x];Remove[S3]
S[x_]:¼in[x/dx], Cos[x/dx], Sin[2*x/dx]};
S3 [x] /. dx -> 2;
Plot[Evaluate@S3, {x, 0, Pi}]
wouter.
At 04:10 12-01-98 -0500, Andreas Keese wrote:
>Look at this:
>
>This works:
> Clear[S1];
> S1Ân[x];
> Plot[S1, {x, 0, 3}]
>
>But why doesn't it work with more than one functions ?
>
> Clear[S2];
> S2¼in[x],Cos[x]};
> Plot[S2, {x, 0, Pi}]
>
>gives an error - Mathematica complains that S2 is not a machine-size
>number.
>
>BTW: I don't want S2 to be pattern cause I want to use this as follows:
>
> Clear[S,dx,S3,x];
> S[x_]:¼in[x/dx], Cos[x/dx], Sin[2*x/dx]};
> S3ïaluate[S[x] /. dx -> 2];
> Plot[S3, {x, 0, Pi}];
>
>
>Bye,
>Andreas
>
>
Dr. Wouter L. J. MEEUSSEN
w.meeussen.vdmcc@vandemoortele.be
eu000949@pophost.eunet.be