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From: "Dan, Ho-Jin" <hjdan@sys713.kaist.ac.kr>
To: jonathan@leto.net
Cc: gsl-discuss <gsl-discuss@sources.redhat.com>
Subject: Re: sf_gamma questions
Date: Wed, 19 Dec 2001 13:20:00 -0000	[thread overview]
Message-ID: <3C0BDFA7.9080408@sys713.kaist.ac.kr> (raw)
In-Reply-To: <20011201214553.A31518@leto.net>

I found that the results from slatec are slightly accurate compare to 
that of slatec.
The relative error of the order O(1.e-15) shows that both routines are 
very accurate.

[17!] error     slatec: 1.875000        [rel:0.000000]
                gsl   : -0.062500       [rel:-0.000000]
[18!] error     slatec: 6.000000        [rel:0.000000]
                gsl   : -1.000000       [rel:-0.000000]
[19!] error     slatec: -80.000000      [rel:-0.000000]
                gsl   : -16.000000      [rel:-0.000000]
[20!] error     slatec: 0.000000        [rel:0.000000]
                gsl   : 0.000000        [rel:0.000000]
[21!] error     slatec: -344064.000000  [rel:-0.000000]
                gsl   : 0.000000        [rel:0.000000]
[22!] error     slatec: 4194304.000000  [rel:0.000000]
                gsl   : -131072.000000  [rel:-0.000000]
[23!] error     slatec: -83886080.000000        [rel:-0.000000]
                gsl   : 0.000000        [rel:0.000000]
[24!] error     slatec: 4697620480.000000       [rel:0.000000]
                gsl   : -134217728.000000       [rel:-0.000000]
[25!] error     slatec: -79456894976.000000     [rel:-0.000000]
                gsl   : -2147483648.000000      [rel:-0.000000]


Jonathan Leto wrote:

>I was writing some test cases for Math::Gsl, when I saw some
>failing, because gamma(19) was off by 1 and gamma(20) is off by
>16. So I wrote a little test program to compare absolute difference
>between gamma(x) and factorial(x-1) . The output was: 
>


WARNING: multiple messages have this Message-ID
From: "Dan, Ho-Jin" <hjdan@sys713.kaist.ac.kr>
To: jonathan@leto.net
Cc: gsl-discuss <gsl-discuss@sources.redhat.com>
Subject: Re: sf_gamma questions
Date: Wed, 28 Nov 2001 12:19:00 -0000	[thread overview]
Message-ID: <3C0BDFA7.9080408@sys713.kaist.ac.kr> (raw)
Message-ID: <20011128121900.QIw02-niWXUhiFYVN4Zp72-gKoqrT6c4USQQpkh5dM0@z> (raw)
In-Reply-To: <20011201214553.A31518@leto.net>

I found that the results from slatec are slightly accurate compare to 
that of slatec.
The relative error of the order O(1.e-15) shows that both routines are 
very accurate.

[17!] error     slatec: 1.875000        [rel:0.000000]
                gsl   : -0.062500       [rel:-0.000000]
[18!] error     slatec: 6.000000        [rel:0.000000]
                gsl   : -1.000000       [rel:-0.000000]
[19!] error     slatec: -80.000000      [rel:-0.000000]
                gsl   : -16.000000      [rel:-0.000000]
[20!] error     slatec: 0.000000        [rel:0.000000]
                gsl   : 0.000000        [rel:0.000000]
[21!] error     slatec: -344064.000000  [rel:-0.000000]
                gsl   : 0.000000        [rel:0.000000]
[22!] error     slatec: 4194304.000000  [rel:0.000000]
                gsl   : -131072.000000  [rel:-0.000000]
[23!] error     slatec: -83886080.000000        [rel:-0.000000]
                gsl   : 0.000000        [rel:0.000000]
[24!] error     slatec: 4697620480.000000       [rel:0.000000]
                gsl   : -134217728.000000       [rel:-0.000000]
[25!] error     slatec: -79456894976.000000     [rel:-0.000000]
                gsl   : -2147483648.000000      [rel:-0.000000]


Jonathan Leto wrote:

>I was writing some test cases for Math::Gsl, when I saw some
>failing, because gamma(19) was off by 1 and gamma(20) is off by
>16. So I wrote a little test program to compare absolute difference
>between gamma(x) and factorial(x-1) . The output was: 
>


  parent reply	other threads:[~2001-12-03 20:26 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-12-19 13:20 Jonathan Leto
2001-11-26 23:50 ` Jonathan Leto
2001-12-19 13:20 ` Jonathan Leto
2001-12-19 13:20 ` Brian Gough
2001-11-29  1:08   ` Brian Gough
2001-12-19 13:20   ` Jonathan Leto
2001-12-01 18:46     ` Jonathan Leto
2001-12-19 13:20     ` Jonathan Leto
2001-12-19 13:20     ` Brian Gough
2001-12-03 15:28       ` Brian Gough
2001-12-19 13:20 ` Dan, Ho-Jin [this message]
2001-11-28 12:19   ` Dan, Ho-Jin
2002-12-31  9:55 Dherminder Kainth
2002-01-03  2:18 ` Dherminder Kainth
2002-12-31  9:55 ` Brian Gough
2002-01-05 11:37   ` Brian Gough

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