MathGroup Archive 2002

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

Search the Archive

RE: Problem with Precision?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg34464] RE: [mg34447] Problem with Precision?
  • From: "DrBob" <majort at cox-internet.com>
  • Date: Wed, 22 May 2002 02:46:46 -0400 (EDT)
  • Reply-to: <drbob at bigfoot.com>
  • Sender: owner-wri-mathgroup at wolfram.com

"Why" is easy: why not?

N affects calculations involved in evaluating its first argument.  It
doesn't change the number if the expression is already a number (even if
you try to DECREASE the number of digits).  You don't want to change the
number anyway; you want to control its display.

For instance, evaluate the following:

x = 1.602176462
NumberForm[1.602176462, 10]
forms = {ScientificForm, EngineeringForm, AccountingForm, BaseForm, 
    PaddedForm}
TableForm[#[10000Pi x, 10] & /@ forms, TableHeadings -> {forms}]

Or, just for grins:

TableForm[#[BaseForm[10000Pi x, 7], 10] & /@ forms, TableHeadings ->
{forms}]

Isn't that fun?

Bobby Treat

-----Original Message-----
From: Mike [mailto:M.P.Croucher at sheffield.ac.uk] 
To: mathgroup at smc.vnet.net
Subject: [mg34464] [mg34447] Problem with Precision?

Can anyone shed any light on why

N[1.602176462,10]

gives

1.60218

I need it to be as accurate as I can get it and 5 dp doesn't cut it.
Any ideas?

Thanks

Mike





  • Prev by Date: Q: Strange Mathematica 3.0.1.1 Behaviour
  • Next by Date: Re: Problem with Precision?
  • Previous by thread: RE: Problem with Precision?
  • Next by thread: RE: Problem with Precision?