FreeLists / si-list / [SI-LIST] Re: spectral domain vs BEM (was non-negative......)

[Ray Anderson <Raymond.Anderson@xxxxxxx>]

Mick-

I was responding to Chris's query about which algorithm the
tool used. He was wondering about which inversion method might
have been used.

I agree, whether the off-diag elements are non-positive or not
depends on the definition of the matrix, but we jumped topics
to discuss another aspect.

-Ray

>
>
>
>>
>>Looks like you are discussing the mathematical aspects of different
>>algorithms. But I think the 
>>original question is about the physical aspects. Should the off-diagonal
>>elements be non-positive
>>or non-negotive ? Fortunately, we can answer it directly based on the
>>definitions, independent  of any numerical examples. It does not matter how
>>you calculate them. So, we can judge the mathematical results. It is very
>>true that all algorithms have drawbacks which lead to numerical 
>>difficulties and errors.
>>
>>Mick
>>
>>
>>-----Original Message-----
>>From: Ray Anderson [mailto:raymonda@xxxxxxxxxxxxxxxxxxxxxxx]
>>Sent: Tuesday, September 04, 2001 4:39 PM
>>To: si-list@xxxxxxxxxxxxx
>>Subject: [SI-LIST] spectral domain vs BEM (was non-negative......)
>>
>>
>>
>>One of the Apsim guys may want to comment, but I believe that the
>>Apsim RLGC tool that I was using implements the spectral domain
>>method which I think is similar to BEM in some respects but
>>different in others. (I'm going to stop right here, I only
>>know enough about this to be dangerous :)
>>
>>RLGC can optionally use the FEM, but it is recommended that FEM be 
>>utilized for more complex structures that are defined with multiple 
>>dielectrics than simple stripline constructs.
>>
>>
>>-Ray
>>
>>
>>
>>>
>>>
>>>which brings into another question,
>>>ray,
>>>was the tool using FEM (most likely using ICCG) or 
>>>BEM (most likely using LU)?
>>>chris
>>>
>>
>

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