Re: New user question
- To: mathgroup at smc.vnet.net
- Subject: [mg20393] Re: New user question
- From: Harald Giese <giese at dkrz.de>
- Date: Tue, 26 Oct 1999 00:32:49 -0400
- Organization: Institut fuer Meereskunde, Universitaet Hamburg
- References: <7uefh0$277@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Thomas Moriarty wrote:
>
> I have just begun to use/learn Mathematica. One of the first things I
> tried was to Plot[x^(1/3),{x,-5,5}] and got error messages indicating that
> the negatives^(1/3) were not machine level real numbers (or close to
> that) - the positive side displayed ok.
>
> What am I doing wrong?
>
Hi Thomas,
Mathematica plots only real numbers, but the roots of negative reals are
complex numbers. Plot[Im[x^(1/3)], {x,-5,5}] will give you the imaginary
part, Plot[Abs[x^(1/3)], {x,-5,5}] the absolute values.
Every time Mathematica does not plot the result you expected, you should
first take a look at some of values you want to have plotted.
Regards,
/Harald
--
Harald Giese
Email: giese at dkrz.de
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