Re: derivatives (and CSG Web
presence)
[Martin Taylor 2004.09.18.21.25]
Marc,
What on earth has been bothering you? Is it just that in
principle nothing said by Bill Powers or Rick Marken can be
correct?
From [Marc Abrams (2004.09.18.1826)]
[From Bill Powers (2004.09.18.1609 MDT)]
[To Marc A]: OK. So you’re sticking with this definition of
thederivative:
Lim (x + h) - f(x)f’(x) = x ->0
---------------;hwhere h is a very small change in x
This is a simple miscopying of x for h. As you say it is h that
approacheszero, not x. As written above, the definition of the
derivative isincorrect. If the error is acknowledged, fine. People make
mistakes. Ifmistakes are not admitted when pointed out, further discussion
is
pointless.
…Yes, I made a transcription mistake, because I used h, rather then
thetriangle and x to indicate a small change in x, but that still
doesn’tchange the fact that my equation was the right one and Powers was
wrong. Getover it.
Lets all move on. It’s over.
Your correction makes matters worse rather than better (you meant
that you used x instead of h, not the other way round).
But that’s not my point. My puzzlement is why you got into this
“pissing match” in the first place.
Going back about 20 messages, we have
(Powers:)
The statement y = f(t) says that
that value of y is some function of time.
The notation f(t) means the value of
the function at time t.The rate of change or derivative of
y with respect to time, or dy/dt, is
computed asf(t2) -f(t1)
dy/dt =
lim ---------------
t2 →
t1 t2 - t1(Abrams:)
Sorry Bill, I guess it’s been awhile, try
this; f’(x) (that’s f prime of x)=Lim
f(x + h) - f(x)
f’(x) = x ->0h ;Where h
is very small change in xA derivative is NOT a change in y with
respect to ‘time’.
Bill says he is talking about a function OF TIME. Furthermore, you
yourself used the notation f’, which by convention refers to a
function of time.
It’s the
INSTANTANEOUS rate of change, i.e. the
slope, for a tangent line on a
continuous point of a curve, for any
mathematical function and it’s a change
in x relative to y. The x axis is often
used as a time line, but not always.
So, you provide the same formula as Bill (apart from your typo
where you say “x” when you meant “h”), and then
you spend 10 or 20 messages slamming him for agreeing with you, and
writing scurrilous screeds about him into the bargain. Not only that,
but you and he are using the same Calc 101 definition. If you wanted
to seem mathematically superior, I think you could have done better,
couldn’t you?
In another message, you say: “I may not be the worlds
deepest thinker and my use of the English language sometimes gets in
the way of my message here, but I’m not a moron…”, and yet you
persist in posting stuff that might lead people to believe the
contrary. It’s rather self-contradictory, and therefore puzzling
puzzling.
To answer another question:
“Hey Martin Taylor, how is ECAC’s
doing? Has your monitoring of the list enabled lots of people who were
reluctant to come onto CSGnet because of the language show up on
ECAC’s? I haven’t seen any activity on the list in quite
awhile.”
The list was rather active for a period, and there were a few
good technical discussions. The problem really was that such a forum
needs critical mass, and if there are only a few active contributors,
the topics in which they are competent tend to get exhausted.
Unfortunately, after you returned to it, many of the threads
developed into (to use your own words on ECACS) “pissing
contests”. With only 7 active members, it’s hard to expect a
technical forum to remain active. It may do so in spurts, but when it
gets flooded with piss, that tends to put a damper on things.
People simply aren’t interested in expressing a tentative idea if
the responses to it aren’t going to be sensible. Nor are they
interested in responding to your own tentative ideas if their attempts
to understand and develop the ideas is going to lead to personal slurs
on their intellectual capability or moral intentions. Nor are they
interested in dialogue with someone who says "
I’m very interested in knowing your ideas but on my terms, not yours"
as a response to an attempt to continue a techical
development.
So, with my longish absence and Bill Williams’ misfortune,
leaving only around 4 active members, not much has been happening
(note to CSG members – on ECACS, Bill W was always a solid
citizen).
···
=====================================================
To all interested in PCT: I note Bruce Abbott’s mention
[2004.09.18.1030 EST]
" Plans were laid to create a new, more comprehensive and
active CSG website".
ECACS (www.ecacs.net) could readily form part of such a site. It
was intended as a discussion forum – meaning that technical threads
can easily be revisited after long periods of dormancy – and as a
place for developing archival documents about PCT. I strongly
recommend that any PCT Web site include the forum concept. Members of
the ECACS forum can choose to see new messages in their e-mail if they
want, but must visit the Web site to post new messages.
Marc referred to “monitoring” the ECACS site. What he
means is that the forum contains an area reserved for personal
references and flame wars, called the “Roughneck Rooms”.
All, and the administrators (Jim Beardsley and I) meant ALL,
potentially insulting personal comment was supposed to be done there,
not in the technical areas of the forum. Marc persisted in violating
that rule of behaviour, and was eventually expelled from ECACS for
refusing to keep the technical discussions technical. He later asked
to return and promised to restrict personal invective to the Roughneck
Rooms, and was allowed to return. But it seems hard for him to sustain
that kind of resolve, and I have recently moved a chunk of his
messages from a technical thread into the Roughneck Room. Presumably
was the source of his comment.
I think it is possible in a forum to eliminate – or to
substantially reduce – the damage to technical discussion caused by
persistent personal attacks, in a way that is impossible in e-mail
discussion. The solution is to enforce the “Roughneck Room”
rule. Someone whose interest is in disrupting the technical discussion
will eventually get frustrated and leave (with luck), but whether he
does or not, the archive of the technical discussion can remain in a
condition open to serious continuation. However, to do this requires
that there be a monitor.
ECACS means “Exploration of Complex Adapting Control
Systems”. The hope was that the forum format with the (as yet
empty) archives would enable more serious discussion and development
of theory, modelling, and actual application, than is readily done
through e-mail. It’s a slightly different focus than is the case of
CSGnet, though many of the CSGnet threads would fit quite well in
ECACS. It would be nice if in some way it could be closely linked with
the new CSG web site.
In a message a few weeks ago, I suggested that the Wiki format
(see http://en.wikipedia.org/wiki/Main_Page)
would be a wonderful component of the CSG Web presence. Has that been
given consideration?
Martin