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Re: Gauss Quadrature

• To: mathgroup at smc.vnet.net
• Subject: [mg128452] Re: Gauss Quadrature
• From: Bob Hanlon <hanlonr357 at gmail.com>
• Date: Sat, 20 Oct 2012 00:34:46 -0400 (EDT)
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• References: <20121019064043.B5205689F@smc.vnet.net>

Specifying a precision rather than using machine precision appears to
resolve the issue.

$Version

"8.0 for Mac OS X x86 (64-bit) (October 5, 2011)"

Needs["NumericalDifferentialEquationAnalysis`"]

And @@ (
  Length[GaussianQuadratureWeights[#, 0, 1, 20]] == # & /@
   Range[150])

True

Even works when specifying a precision less than machine precision

And @@ (
  Length[GaussianQuadratureWeights[#, 0, 1, 10]] == # & /@
   Range[150])

True


Bob Hanlon


On Fri, Oct 19, 2012 at 2:40 AM, Brambilla Roberto Luigi (RSE)
<Roberto.Brambilla at rse-web.it> wrote:
> Hello friends,
>
>
>
> I have found that the following instructions  with Mathematica-8.0
>
>
>
> <<"NumericalDifferentialEquationAnalysis`"
>
>
>
> GaussianQuadratureWeights[n,0,1]
>
>
>
> does NOT work with the following values of n :
>
>
>
> 38  40  72  86  118  121  124  130 ...
>
>
>
> Then I stopped.
>
> The same command with ver.5.1 works fine with all numbers.
>
> Please, can some of you test this oddity ?
>
>
>
> Many thanks, Roberto
>
>
>

• References:
  • Gauss Quadrature
    • From: "Brambilla Roberto Luigi (RSE)" <Roberto.Brambilla@rse-web.it>