On 12/17/2018 9:40 AM, Jon Awbrey wrote:
> when I use the word “system” a great many people are not thinking
> what I'm thinking when I use it. The first thing in my mind is
> almost always a state space X and the possible trajectories of
> a representative point through it. But a lot of people will be
> thinking of a “system”, like the word says, as a collection of
> parts “standing together”.
General principle for anybody who is trying to state a formal
definition of any word for any purpose: Check a good dictionary
to see how the word is used in well-edited publications.
In fact, the ISO standards organization explicitly recommends
the Oxford English Dictionary. Another good option is the very
convenient Merriam-Webster web site (which shows up near the top
whenever you type any single word to Google).
See below for the M-W definition for 'system'. Note that a
state space is not in that list. But it could be considered
a special case of sense 1d:
"A group of devices or artificial objects or an organization
forming a network especially for distributing something or serving
a common purpose. Examples: a telephone system, a heating system,
a highway system, a computer system."
At the end of the article, M-W states the etymology and discusses
how the word 'system' differs from similar words:
"Method, mode, manner, way, fashion, system mean the means taken
or procedure followed in achieving an end... System suggests a fully
developed or carefully formulated method often emphasizing rational
orderliness. Example: a filing system."
Your definition of 'system' could be considered "a carefully
formulated method" that has "rational orderliness."
But the state space is not likely to be the first thing that
comes to the minds of 99.9% of readers. You might call it
a "state-space system", give a short definition, and include
a URL for further info.
Recommendation: In my 1984 book and my 2000 book, I recommended
that anybody who is writing definitions for any technical purpose
should keep a good dictionary on the desk or a nearby shelf. Today,
you can (and should) Google the word.
The Merriam-Webster definition of 'system':
1 : a regularly interacting or interdependent group of items forming
a unified whole. Example: a number system.
1a(1) : a group of interacting bodies under the influence of related
forces. Example: a gravitational system
1a(2) : an assemblage of substances that is in or tends to equilibrium
Example: a thermodynamic system
1b(1) : a group of body organs that together perform one or more vital
functions. Example: the digestive system
1b(2) : the body considered as a functional unit
1c : a group of related natural objects or forces.
Example: a river system
1d : a group of devices or artificial objects or an organization forming
a network especially for distributing something or serving a common
purpose. Examples: a telephone system, a heating system, a highway
system, a computer system
1e : a major division of rocks usually larger than a series and
including all formed during a period or era
1f : a form of social, economic, or political organization or practice.
Example: the capitalist system
2 : an organized set of doctrines, ideas, or principles usually intended
to explain the arrangement or working of a systematic whole.
Example: the Newtonian system of mechanics
3a : an organized or established procedure.
Example: the touch system of typing
3b : a manner of classifying, symbolizing, or schematizing a taxonomic
system. Example: the decimal system
4 : harmonious arrangement or pattern : order.
Example: "bring system out of confusion" — Ellen Glasgow
5 : an organized society or social situation regarded as stultifying or
oppressive : establishment sense 2