Re: [Fwd: table model updates [corrected]]

[Forwarded for tarek_salah@mentorg.com]

Hi,

Please I need to ask about extrapolation of data for more than 1D case.
I think that for 1D case it's simple that if (Xin>Xmax ) or (Xin<Xmin)
then Xin should be treated as a point needing extrapolation.

But, for higher dimensions & given that the data is scattered, how
mathematically is a point defined as needing extrapolation?

Thanks,
Best Regards,
Tarek

>
> -------- Original Message --------
> Subject: table model updates [corrected]
> Date: Fri, 30 Jul 2004 12:55:43 -0400
> From: "Geoffrey.Coram" <Geoffrey.Coram@analog.com>
> To: Chandrasekaran Srikanth-A12788
> <Srikanth.Chandrasekaran@freescale.com>, "Martin O'Leary"
> <oleary@cadence.com>, Verilog-ams@eda.org
> References:
> <643810D0E0F1144C8F9D798CF5294DD803FD26CC@zas24exm01.corp.mot.com>
>
>
>
>[had "paramset" where I meant "table model"]
>
>Sri asked that I send out an e-mail detailing the substantive changes between the last table model proposal that was sent to the list and the actual material added to the LRM draft f.
>
>
>* the table model proposal from Martin had multi-dimensional arrays, which are not part of AMS; he said I could remove this feature from table model and wait for m-d arrays to be added to AMS.
>
>* splines have extra degrees of freedom; the following paragraph was added to address this:
>
> For both quadratic and cubic interpolation, extra constraints
> are necessary to generate a unique spline over the supplied
> data points. For quadratic interpolation, Lagrange
> interpolation is used to fit a quadratic polynomial over the
> first three data points (those with lowest coordinate values);
> the second derivative of this polynomial is used to specify
> the second derivative of the quadratic spline at the first
> data point. For cubic interpolation, Lagrange interpolation
> is used to fit a cubic polynomial over the first four data
> points and the last four data points, and this polynomial
> is used to determine the second derivative of the cubic
> spline at the first and last data points. If there are not
> enough data points, the second derivatives are assumed to be
> zero.
>
>Note that this differs from the "natural" cubic spline, but gives the user the flexibility to control the derivative at the endpoints by adding extra points.
>
>
>--
>Geoffrey J. Coram, Ph.D. Senior CAD Engineer
>Analog Devices, Inc. Geoffrey.Coram@analog.com
>804 Woburn St., MS-422, Tel (781) 937-1924
>Wilmington, MA 01887 Fax (781) 937-1014
>
>
Received on Thu Aug 5 15:27:56 2004