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# Re: FEMM Vs. commercial code

- To: femm@yahoogroups.com
- Subject: Re: FEMM Vs. commercial code
- From: "marsupiofr" <marsupio@hotmail.com>
- Date: Thu, 14 Nov 2002 21:34:48 -0000
- In-reply-to: <5.1.0.14.0.20021114084924.01d79b28@staff-mailin.lboro.ac.uk>
- User-agent: eGroups-EW/0.82

    Great post Keith !!!

    I really agree on every points you mentionned. FEMM is also a
    good "starting" software if you want later to migrate to a big
    commercial platform. In FEMM, you (or you should) really know what
    you are doing. That's also true on big commercial platforms but you
    are often lost in so many options. With FEMM, you can learn the
    basics. The LUA extensions have also really boosted the software
    functionnalities. If you add the very clear user interface, the great
    documentation,... Honestly, that rocks !!!

    --- In femm@y..., Keith Gregory <k.gregory@l...> wrote:
    > Well ....
    >
    > There are many differences between FEMM and typical commercial code
    but I
    > don't think that in the important area (i.e. kern - the solver )
    there is
    > much difference. FEMM is as good as if not better than a lot of
    commercial
    > stuff. David has taken advantage of a very good mesh generator and
    produced
    > an excellent piece of software. That said it is not bullet proof
    and David
    > would be the first to admit that it does fall over occasionally in
    ways
    > that most commercial code would not. This to me is part of its
    attraction,
    > I use FEMM for teaching and it makes students think much more about
    what
    > they are doing than most commercial code would. It also has the
    significant
    > advantage for those who have little nor no spare money (i.e UK
    Academics!)
    > that it is free in a market that is occupied by software that can
    be
    > inordinately expensive. The first commercial finite-element code
    that I
    > ever used required a main-frame to run it and cost over £10,000
    (around
    > $30,000 in those days).
    >
    > The problem that I have with a lot of commercial code is that it is
    > overblown, by which I mean that it covers up a lot of what it is
    doing in
    > the name of an easy user interface. FEMM does not do that although
    its user
    > interface is one of the most straightforward that I have ever come
    across -
    > only one commercial code that I know of comes close for ease of
    use. FEMM
    > does not have any of the almost CAD like drawing tools that
    commercial code
    > usually has. However, a little bit of ingenuity and old fashioned
    > draftsmanship usually allow a problem to be drawn directly in FEMM.
    I only
    > resorted to DXF import in the earlier versions of FEMM I feel no
    need to now.
    >
    > FEMM does not have adaptive meshing you have to refine meshes by
    hand where
    > most commercial code does it automatically. I do not find this to
    be a
    > problem because most computers these days eat large problems so
    often I
    > just use fine meshes!
    >
    > FEMM does not include other integrated solvers such as the
    electrostatic,
    > thermal or mechanical stuff that some commercial software includes.
    >
    > FEMM requires you to set boundary conditions explicitly where (I
    think)
    > some commercial codes can do it (semi?) automatically.
    >
    > FEMM circuit facilities are in their infancy for example they
    cannot
    > directly integrate external circuitry as many commercial codes can.
    (I am
    > of the opinion though that this may be possible using lua scripts).
    >
    > FEMM cannot deal with dynamic (transient) situations as some
    commercial
    > codes can.
    >
    > FEMMVIEW (the postprocessor) has most if not all of the tools that
    > commercial code has but requires you to understand what they do in
    order to
    > use them effectively. Many commercial codes attempt to determine
    things
    > like inductance at the push of a button, this has always worried me
    and I
    > find I don't trust the results. That said FEMMVIEW does not produce
    such
    > polished results as most commercial code and lacks some of the
    common
    > plotting facilities such as vector displays.
    >
    > FEMMPLOT is useful but not something that you would use to produce
    > presentations. Most commercial code can produce camera ready stuff
    (all
    > show no substance?).
    >
    > The addition of lua scripting has given FEMM very powerful
    facilities that
    > far exceed many commercial efforts. One of my undergraduate project
    > students is now using FEMM in conjunction with MatLab and lua
    scripts of
    > hundreds of lines of code to produce very effective interactive
    design tools.
    >
    > I have found, over a few years of use now, that FEMM can do
    virtually
    > everything that I need to do as well as and sometimes better than
    the
    > commercial code that I have used in the past.
    >
    > FEMM is a simple, straightforward but very powerful piece of
    software that
    > does exactly what it says on the tin! (apologies for a reference
    that may
    > only be understood in the UK). Finally, FEMM has one singular
    advantage
    > over all commercial software - it's written and maintained by
    someone who
    > is not anonymous, who will talk to you and listen to what you say.
    You
    > cannot put a price on that.
    >
    > Keith.
    >
    >
    >
    >
    >
    > At 21:43 12/11/2002 +0100, you wrote:
    > >Which are main differences?
    > >
    > >
    > >
    > >
    > >
    > >
    > >Your use of Yahoo! Groups is subject to
    http://docs.yahoo.com/info/terms/

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- References:
  - Re: [femm] FEMM Vs. commercial code
    - From: Keith Gregory <k.gregory@lboro.ac.uk>

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