
The lost art of Nomography - xtacy
http://myreckonings.com/wordpress/wp-content/uploads/JournalArticle/The_Lost_Art_of_Nomography.pdf
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jfoutz
This is fascinating. I'm a programmer, and somewhat familiar with digital
circuits. I'd never really understood how someone would go about constructing
an analog computer. This is it, bang on. Resistors for linear changes,
capacitors for exponential curves. Pretty neat, an array of meters coupled
with a bunch of analog components would solve (approximately) really
complicated stuff.

It's also pretty neat you can get an approximate solution in a single step,
rather than cranking through a bunch of operations. It seems like a
compression problem in information theory, especially when you consider the
two step or multi step graphs.

~~~
kragen
Capacitors (well, RC systems) are exponential in _time_ , but their
relationship between voltage and current is purely linear. So if you want to
use capacitors to do exponentials, and your machine inputs are in voltage or
current, you need a way to convert a voltage or current to a time delay.

More typically, I think electronic analog computers used the exponential
region of a semiconductor diode to do logarithms and exponents, and thus
multiplication and division, in nanoseconds, using 1950s technology. You can
use capacitors and inductors to integrate and differentiate time-varying
functions.

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dimitar
I upvoted this article because it is really interesting, but unfortunately I
disagree that nomography can be relevant today. It is forgotten so easily
because its not worth the effort with the availability of computers. Computers
aren't hard to use and to learn how to use. Try doing through the exhaustion
of doing numerical calculations for a day with a slide rule and nomograms to
see why.

~~~
neonkiwi
I disagree with the sentiment that nomography has lost relevance. Anybody
worth their salt doing interface design for complex systems is exploiting
these principles and combining nomography and computing.

For example, a power plant is littered with sensors, reading various
pressures, temperatures, valve settings, etc. The traditional interfaces—a
dial for every value, as per Three Mile Island—does not help a human operator
in understanding the relationships in the data. Today, interfaces are designed
to better explain how different parts of a system interact, and a nomograph
can help an operator build a better mental model of how a change in a series
of inputs affects an output.

A simple calculation on a computer can produce all of the numbers defining the
operating point of a turbine, but a good nomograph will convey the physical
relationships of the system.

I realize these types of displays aren't seen by most people on a regular
basis, but they're far from irrelevant.

~~~
dimitar
I imagine something like a dynamic bode plot, from which you can judge the
stability of a system.

But that is a plot of data, not an analog computing method on paper. You can
simply improve the presentation or organization on data. I suppose operators
have computers nowadays :-).

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jotango
Nomographs are often used in airplane manuals. When your power plant dies, you
still want to be able to calculate your range based on speed, altitude etc.

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smoyer
I'm probably older than most of the people here, but the slide-rules that I
used for 10th grade chemistry were essentially nomographs (fortunately I had a
calculator by the time I took physics in 12th grade). I have a couple that I
keep around for sentimental reasons but haven't used them in years.

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gking86
I'm a CBRNE specialist, and we use these for estimating yield of nuclear
detonations based on various paramaters (flash-to-bang time, angular width of
cloud top, etc.)

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hadronzoo
I'm surprised the author didn't mention the Smith chart:
<http://en.wikipedia.org/wiki/Smith_chart>

~~~
shithead
First thing in the series of blog articles:
[http://myreckonings.com/wordpress/2008/01/09/the-art-of-
nomo...](http://myreckonings.com/wordpress/2008/01/09/the-art-of-nomography-i-
geometric-design/)

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phren0logy
Meta-comment: I know I saw something about this before, but why is it that any
PDF gets a [scribd] tag, even when it has nothing to do with scribd.com? It
doesn't make any sense.

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0x12
Because HN promotes scribd (A YC company).

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marchdown
I don't get scribd. It's annoying to get a link to their site with various
limitations and cludges screwed on top of otherwise perfectly readable
document.

Since this is YC company, don't you happen to now if there is some not-
trivially-googleable place where I can read about their agenda or fundraising
pitch?

~~~
rgovostes
Scribd is awful and it's an embarrassment to this site and to Y Combinator.
There have been countless posts here decrying paywalls set up by academic
journals, yet while Scribd is hardly any better, they're accepted and even
promoted within this community.

On the surface, the ability to convert a PDF to an almost-lossless HTML
document is great technology for those who use archaic browsers that balk at
PDF files. For this, I give them a pass for inserting obnoxious dynamic
advertisements in between pages of the document and in the sidebar.

The actual service, however, is misleading and downright hostile towards
users. Let me try to download the linked PDF from Scribd, using the attractive
green "Download" button. Oh, I need an account. Let me log in with Facebook.
This is what it requests from me:

* My name, profile picture, gender, networks, list of friends, and other shared profile information.

* My e-mail address, so it can send me e-mail.

* The ability to post to my Wall.

* The ability to access all posts in my News feed, including friends' posts.

* Access to my data even when I'm not using Scribd.

Mind you, this is just to download a PDF, which Scribd did not author!

What's worse, after some amount of time, the linked PDF will be moved into the
Scribd Archive, from which it can only be downloaded after you upload
something new, or agree to pay at least $5. After opening up your private life
to Scribd, you can open up your wallet too.

