From Greg.Snow at imail.org  Wed Aug  5 01:30:35 2009
From: Greg.Snow at imail.org (Greg.Snow at imail.org)
Date: Wed,  5 Aug 2009 01:30:35 +0200 (CEST)
Subject: [Rd] Accuracy (PR#13867)
Message-ID: <20090804233036.3B921282EFFB@mail.pubhealth.ku.dk>

What research into this problem did you do that failed to turn up FAQ 7.31?

--=20
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
801.408.8111


> -----Original Message-----
> From: r-devel-bounces at r-project.org [mailto:r-devel-bounces at r-
> project.org] On Behalf Of luethman at student.ethz.ch
> Sent: Tuesday, August 04, 2009 8:25 AM
> To: r-devel at stat.math.ethz.ch
> Cc: R-bugs at r-project.org
> Subject: [Rd] Accuracy (PR#13867)
>=20
> Full_Name: Manuel Luethi
> Version: 2.9.1
> OS: Windows XP
> Submission from: (NULL) (129.132.128.136)
>=20
>=20
> Hi
>=20
> I created the following vectors:
>=20
> p_1=3Dc(0.2,0.2,0.2,0.2,0.1,0.25,0.4,0.1,0.25,0.4,0.1,0.25,0.4,0.1,0.25,0
> .4,0.2,0.5,0.8,0.2,0.5,0.8,0.2,0.5,0.8,0.2,0.5,0.8)
> p_2=3Dc(0,0,0,0,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.5,0.4,0.25,
> 0.1,0.4,0.25,0.1,0.4,0.25,0.1,0.4,0.25,0.1)
>=20
> As these are probabilities, I calculated the remainder as
>=20
> p_3=3D1-p_1-p_2
>=20
> There the values which ought to be 0.1 were lateron not recognised by
> p_3=3D=3D0.1,
> but only if I used p_3 <=3D 0.1.
>=20
> The full calculation is actually bigger but the core issue remains: I
> used
> values input by hand, built a difference and it was wrong.
>=20
> I know that exactly the value 0.1 is one that can not be represented
> using
> binary rep. Maybe that's it, maybe not. Just wanted to let you know.
>=20
> With kind regards
>=20
> Manuel
>=20
> ______________________________________________
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> https://stat.ethz.ch/mailman/listinfo/r-devel



[Rd] Accuracy (PR#13867)
Greg.Snow at imail.org