On 28/10/2010 20:44, Olin Lathrop wrote:
> Oli Glaser wrote:
>>> 2 - You still rely on knowing parameters of the train, which in this
>>> case is the spacing between wheels.
>> Of course, but I thought that part was rther obvious.. :-)
> But yet you suggested a method with this obvious drawback.

It is not a drawback if the parameters are known. As I said before, it=20
depends on the situation. If there are standard parameters like these,=20
then they can be used to ones advantage. If not, then obviously you can=20
consider other options.

>> Note the "something like" in my post - it depends a lot on what
>> information is available, and the situation (which I am mostly in the
>> dark about)
>> For instance, if all trains are a standard length, then it could be as
>> simple as timing the duration of the noise.
> Why go to great lengths to concoct a system that might sortof work if
> everything is right and only Standard Trains pass by, when much simpler a=
nd
> reliable methods are readily available?

I wasn't aware of any "great lengths" involved, and again it depends on=20
many things as to which methods will be the simplest/most reliable.

>> plenty of ways to do this..
> That's the point.  There are plenty of ways that can be dreamt up to do
> this, but not that many that are simple to implement, reliable, cheap,
> readily doable, and don't require the train to be just right.  As I
> understood the question, it was a practicle one, not a theoretical one.  =
Do
> you really think futzing around with a DSP algorithm to detect the right
> sound, and then assuming a particular wheel spacing makes sense as a meth=
od
> of getting the job done?  Do you really think that is quicker to implemen=
t
> and tweak than a couple of magnetic sensors, and that it will work in mor=
e
> circumstances and stay working in the real world longer?  Right, I didn't
> think so.
>

:-)
It was just an idea thrown into the pot, and the quickest and easiest=20
solution is liable to be whichever the OP is most comfortable with, and=20
fits with the situation best.

> While it may be interesting from a theoretical point of view, it's frankl=
y
> silly if you just want to solve the problem.  If you want to muse about
> theoretical solutions, thats fine as long as you label them as such.  You=
r
> message made it sound like you were seriously proposing this as a real
> solution, which is doing the OP a disservice.

I was seriously propsing it as a suggestion. That's what the OP was=20
asking for, at least that's the impression I got. I personally think=20
that the more ideas thrown into the pot the better, even if some are a=20
bit more "out there" they may help trigger a useful idea, or be used in=20
combination to present a more effective solution.
I don't think I was doing anyone a "disservice", it was certainly not my=20
intention. If the Op feels differently I do apologise though, and will=20
try to refrain from having any further "ideas" or forgetting to label=20
them appropriately.. :-)



--=20
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