Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2000
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2000

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Faulty feature of Factor?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg25145] Re: Faulty feature of Factor?
  • From: "Allan Hayes" <hay at haystack.demon.co.uk>
  • Date: Sun, 10 Sep 2000 21:25:39 -0400 (EDT)
  • References: <8pfd6a$cs0@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

Jack,
Maybe with inexact coefficients,  N[the leading coefficient]  is extracted

Suggestion for work around:

{Factor[x - 0.1], Factor[ -4 I x^2 - x + .45]}

{1.*(-0.1 + 1.*x), (4. + 0.*I)*
   (0.12917010694971984 + 0.22130847988008057*I - I*x)*
   (0.22130847988008057 - 0.37917010694971987*I + x)}

% /. x_ /; FractionalPart[x] == 0 :> IntegerPart[x]

{-0.1 + x, 4*(0.12917010694971984 + 0.22130847988008057*
      I - I*x)*(0.22130847988008057 - 0.37917010694971987*
      I + x)}.



Allan
---------------------
Allan Hayes
Mathematica Training and Consulting
Leicester UK
www.haystack.demon.co.uk
hay at haystack.demon.co.uk
Voice: +44 (0)116 271 4198
Fax: +44 (0)870 164 0565

"Jack Goldberg" <jackgold at math.lsa.umich.edu> wrote in message
news:8pfd6a$cs0 at smc.vnet.net...
> Hi group,
>
> Guess what Mathematica returns when you ask for   Factor[x-.1] ?  Don't
peek;
> guess first.
>
> If this is a feature, please explain its usefulness.
>
> If this is a (pardon the b-word) bug, how can one get around it?
>
> The same difficulty arises in many other cases, but this seems to me to be
> the most egregious.
>
> Thanks everyone.
>
> Jack
>
>




  • Prev by Date: Re: Displaying Mixed Numbers
  • Next by Date: Re: Re: Security considerations in Mathematica&J/Link
  • Previous by thread: Faulty feature of Factor?
  • Next by thread: Syntax Error in .nb File