Hello Ted
thanks for the comments below.
You point out below some less-than-perfect aspects of
some of my documentation (bizarrely, this is not the first time that
this
has happened. The real problem is that *other people* insist on
reading the docs, when as everyone knows, the real purpose
On 31-Aug-07 13:06:42, Prof Brian Ripley wrote:
> On Fri, 31 Aug 2007, Robin Hankin wrote:
>
>> Hi Kris
>> lgamma() gives the log of the gamma function.
>
> Yes, but he used Igamma. According to ?pgamma,
>
> 'pgamma' is closely related to the incomplete gamma function.
> As defined by Abram
> "AN" == Anup Nandialath <[EMAIL PROTECTED]>
> on Fri, 31 Aug 2007 13:15:08 -0700 (PDT) writes:
AN> Hi Kris, You just need to understand the mathematics of
AN> the incomplete gamma function and the various
AN> relationships it has. The answers from both Mathematica
AN>
Hi Kris,
You just need to understand the mathematics of the incomplete gamma function
and the various relationships it has. The answers from both Mathematica and R
are correct, except that they are giving you different estimated quantities. It
depends on the way the gamma function is written.
On 31 Aug 2007, at 14:06, Prof Brian Ripley wrote:
> On Fri, 31 Aug 2007, Robin Hankin wrote:
>
>> Hi Kris
>>
>>
>> lgamma() gives the log of the gamma function.
>
> Yes, but he used Igamma. According to ?pgamma,
>
> 'pgamma' is closely related to the incomplete gamma function. As
> d
On Fri, 31 Aug 2007, Robin Hankin wrote:
> Hi Kris
>
>
> lgamma() gives the log of the gamma function.
Yes, but he used Igamma. According to ?pgamma,
'pgamma' is closely related to the incomplete gamma function. As
defined by Abramowitz and Stegun 6.5.1
P(a,x) = 1/Gamma(
Hi Kris
lgamma() gives the log of the gamma function.
You need gamma_inc() of the gsl package, a wrapper for the
GSL library:
> gamma_inc(9,11.1)
[1] 9000.501
>
HTH
rksh
On 31 Aug 2007, at 00:29, [EMAIL PROTECTED] wrote:
> Hello
>
> I am trying to evaluate an Incomplete gamma function
Hello
I am trying to evaluate an Incomplete gamma function
in R. Library Zipfr gives the Igamma function. From
Mathematica, I have:
"Gamma[a, z] is the incomplete gamma function."
In[16]: Gamma[9,11.1]
Out[16]: 9000.5
Trying the same in R, I get
> Igamma(9,11.1)
[1] 31319.5
OR
> Igamma(11.1,9
> "MM" == Martin Maechler <[EMAIL PROTECTED]>
> on Tue, 8 Aug 2006 09:55:50 +0200 writes:
> "Leo" == Leo Gürtler <[EMAIL PROTECTED]>
> on Tue, 08 Aug 2006 00:13:19 +0200 writes:
Leo> Dear R-list,
Leo> I try to transform a mathematica script to R.
Leo> ###
