HDTenEightyP/NetNews huggingface dataset:
From: markh@csd4.csd.uwm.edu (Mark)
Newsgroups: comp.programming
Subject: Re: Costs per line of code
Date: 10 Oct 1992 20:21:17 GMT
Organization: Computing Services Division, University of Wisconsin - Milwaukee
NNTP-Posting-Host: 129.89.7.4

markh@csd4.csd.uwm.edu (Mark) writes:
:If I write an expert system that can generate programs from voice specification
:how much do I charge for the software I tell it to develop?

In article <1992Oct07.130107.18257@cadlab.sublink.org> martelli@cadlab.sublink.org (Alex Martelli) writes:
>For 17 years, the time your patents on it will last, what you can charge is
>based on your COMPETITORS' cost for the same final products...

I could also charge 1/4 of all the competitors' prices and thus gain a complete
monopoly on the entire software market as well, not just a patent-enforced
monopoly on the expert system.

Then one year and $1 billion later I could generously make everything public
domain.
Newsgroups: comp.programming
From: dak@tabaqui.informatik.rwth-aachen.de (David Kastrup)
Subject: Re: Calculating a CRC of other CRCs
Organization: Rechnerbetrieb Informatik  /  RWTH Aachen
Date: 11 Oct 92 17:25:41 GMT

usenet@nntpd.lkg.dec.com (USENET News System) writes:

>In article <1992Oct5.103012.9011@iccgcc.decnet.ab.com> schmidtg@iccgcc.decnet.ab.com writes:
>>
>>In addition, the program is organized as "chunks" and a chunk may be
>>independently edited.  However, when the chunk is edited, I would like to
>>avoid having to recalculate the CRC for the entire program.  I would like to
>>somehow "incrementally" update the CRC based on a small change.

>Why use CRCs?

Because simple changes completely foul up CRCs, so that matching of CRCs
is really a more or less probabilistic matter. If a programmer misspells
a word by transposing two characters, simple checksums will not see the
correction. CRCs become entirely different by such small changes.

If 2 CRCs really match wrongly, it is usual a freak accident with low
probability (reverse than number of different possible CRCs), not a
weakness of the CRC generator itself.

I agree that for the proposed problem a checking of modification times
would be the better course, given the OS provides it.
From: martelli@cadlab.sublink.org (Alex Martelli)
Newsgroups: comp.programming
Subject: Re: Costs per line of code
Date: 7 Oct 92 13:01:07 GMT
Organization: CAD.LAB S.p.A., Bologna, Italia

markh@csd4.csd.uwm.edu (Mark) writes:
	...
:If I write an expert system that can generate programs from voice specification
:how much do I charge for the software I tell it to develop?

For 17 years, the time your patents on it will last, what you can charge is
based on your COMPETITORS' cost for the same final products; that is, you
will be able to sell as much expert-system-developed-software as you can
produce, as long as you make customers pay for such software a smidgeon
less than they would have to pay for software of identical functionality
and quality if they should purchase it from other suppliers.

Once your monopoly on this technology expires, everybody and his cousin
will be able to supply such very-low-production-cost software, so
competition will drive the prices into the ground and software will
become an extremely cheap commodity.

If the expert system can only develop SOME kind of programs, then only
the market for programs of that kind will be affected; if the
expert-system generated programs have some serious faults (suppose they
typically run an order of magnitude slower than traditionally-produced
competing programs), or some serious benefits (suppose they NEVER, but
NEVER, suffer from any sort of design or coding bug, so if the specs are
perfect so will the software be), the effects will be, respectively,
dampened or amplified.

One could envisage quite a few variant scenarios (what if... the patent
was seriously attacked? the originator decided to license the technology
rather than using it for direct production? and so on), but a basic
knowledge of economics and allied matters makes this into a not very
challenging conumdrum.
-- 
Email: martelli@cadlab.sublink.org                   Phone: ++39 (51) 6130360
CAD.LAB s.p.a., v. Ronzani 7/29, Casalecchio, Italia   Fax: ++39 (51) 6130294 
Newsgroups: comp.programming,comp.lang.c,comp.lang.pascal,comp.lang.objective-c
From: mcdonald@aries.scs.uiuc.edu (J. D. McDonald)
Subject: Re: NO NUMBERS! (or even SHORT INTS!)
Summary: bc - an arbitrary precision calculator with a C-like syntax
Organization: UIUC SCS
Date: Sun, 11 Oct 1992 20:29:05 GMT
Keywords: pi calculator precision

In article <1992Oct11.192931.14366@seas.smu.edu> mustafa@seas.smu.edu (Mustafa Kocaturk) writes:


>There are software tools that give more precision than that available
>in hardware.  The arbitrary precision calculator utility `bc' that is
>available on Unix systems,

:-) :-) ;-) 

Historical post warning!!!
**************************************************************************

You could also use the IBM 1620, which allowed operating on words up
to 20,000 decimal digits long, fixed or float. (Not exactly in "hardware"
since it didn't **have** adder or multiplier hardware, but nevertheless
could add and multiply words that long in a single instruction.)

I calculated "e" to 9000 digits once, programming the machine in machine
language (not assembler) and it chugged out the answer correctly.

Doug McDonald
Newsgroups: comp.programming
From: schall@swtech06.cfsat.honeywell.com (Loren Schall)
Subject: Is a generic finite state machine engine reasonable?
Organization: Honeywell Air Transport Systems Division
Date: Mon, 12 Oct 92 16:24:39 GMT

Hello Netters, a colleague of mine brought me an interesting question
and I knew that you would have some useful input.

We're involved with a large realtime application that includes several
pieces which could reasonably be implemented as finite state machines.
Is it possible and reasonable to implement a "generic" finite state
engine?  Please reply via e-mail and I'll summarize and re-post.  If
you think this is an inapropriate place for this discussion, tell me
where the right place is.

I'm envisioning a (static) initialization step where the specific
machine is defined (inputs, transitions, and outputs) and an
invocation process taking an input and producing an output (the
actual state transition being internal and invisible).

The main objective we're looking for is ease of maintenance.  We
believe that it would be easier to maintain several state machine
descriptions and one implementation, than several different state
machine implementations.

Does anyone know of any appropiate references or examples (Ada, C,
or C++ would be must useful).

Thanks, in advance, for any help you can offer.

Loren
schall@swtech.cfsat.honeywell.com (Loren Schall)
Newsgroups: comp.programming
From: gillies@m.cs.uiuc.edu (Don Gillies)
Subject: Re: Calculating a CRC of other CRCs
Organization: University of Illinois, Dept. of Comp. Sci., Urbana, IL
Date: Thu, 8 Oct 1992 21:51:54 GMT

Here is a warning.  If you reorder the statements in a program, then
an 8-bit CRC will not change.  If you employ a 32-bit CRC, then there
is still a 1/16 chance that any given statement reordering will not
change the CRC.

CRC's may not be what you want for program text.

- Don
-- 



Newsgroups: comp.programming
From: torbenm@diku.dk (Torben AEgidius Mogensen)
Newsgroups: comp.programming
Subject: Re: Pseudo-Random number generators
Date: 14 Oct 92 10:58:29 GMT
Organization: Department of Computer Science, U of Copenhagen

jan-o@hsr.no (Jan Ove Haaland) writes:

>I'm interested in algorithms for generating pseudo random numbers.
>Unfortunately such algorithms are hard to come by, and nobody else around
>seem interested, as random functions is found in all "decent" programming
>languages. I'm not going to give up assembly, so I ask:

>What is the shortest (computationally) algoritm for generating
>pseudo random (integer) number, with even number distribution, and
>loops at least about 2^32 before repeating ?

How about

	t = (t+1) & 0xffffffff;

?

It loops at exactly 2^32. It has an even number distribution (all
numbers 0 .. 2^32 occurs exactly once in the loop). It is extremely
efficient (you might even avoid the & 0xffffffff if you know your
numbers are 32 bit). It is, however, not very random. It gets a little
better if you add a large prime instead of one, but the low order bit
will always change by a period of 2.

For better algorithms, see Knuth's The Art of Computer Programming,
vol. 2: semi-numerical algorithms. The most efficient and reasonably
good algorithms are based on a shift register. I think something like

  add a constant
  rotate bits by a prime amount

works reasonably well. The period depends on a combination of word
length, amount of rotation and what constant is added.

	Torben Mogensen (torbenm@diku.dk)
Newsgroups: comp.programming
From: mjs@hubcap.clemson.edu (M. J. Saltzman)
Subject: Re: NO NUMBERS! (or even SHORT INTS!)
Organization: Clemson University, Clemson SC
Date: Fri, 9 Oct 1992 16:28:56 GMT

In article <392@ulogic.UUCP> hartman@ulogic.UUCP (Richard M. Hartman) writes:
>>[...]
>>After some time, a major change was made, line had to change to
>>#define FOUR 5
>>
>
>There was a really old bug I heard of once.  FORTRAN compiler

Well, if we have to repeat urban legends, let's at least get them right.

>kept literal values as if they were variables (who knows why,
>perhaps it had to do w/ the machine architecture....) so when 

Most compilers do this.  Not every use of a literal constant can expand
to a machine instruction with the literal as an operand.

>a typo occurred, instead of:
>	i3 = i1+1
>they had:
>	3 = i1+1

No, the way it worked was as follows:  Fortran passes subroutine arguments
by reference, so a call to FOO(3) passes the address of the location of
the copy of the constant 3 to FOO.  Now if we had

	SUBROUTINE FOO(I)
	I = 6
	RETURN
	END

then 6 would be stored in the location where the program expects to find 3.

>and from then on the numeric constant '3' in the program was
>interpreted as whatever the value of "i1+1" was at the time
>(i.e. if i1 had been 5, i1+1 would have been 6 and from then
>on,
>	i2 = 1+3
>would set i7 to the value of 9!!!)
>
>Aren't you glad that compilers today are perfect?		;)

Many modern Fortran compilers are at least smart enough now to treat a
constant argument as an expression, compute its value, store that in a
temporary location, and pass the address of the temp, but IT'S
NOT REQUIRED!  The Fortran standard says that the result of modifying
a parameter to a subroutine is UNDEFINED if the actual argument is 
an expression (in C parlance, "not an lvalue"), so the above behavior
is perfectly appropriate (and so is executing the machine instruction
KILL PROGRAMMMER IMMEDIATE).

We never see this kind of problem come up on comp.lang.c, now do we?  8^) 8^)

>
>		-Richard Hartman
>		hartman@ulogic.COM
>
>=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
>Moderation in all things....		         ....especially moderation.
>


-- 
		Matthew Saltzman
		Clemson University Math Sciences
		mjs@clemson.edu
Newsgroups: comp.programming
From: neuhaus@vier.informatik.uni-kl.de (Stephan Neuhaus (HiWi Mattern))
Subject: Re: A good 'diskette-filling' algorithm?
Organization: University of Kaiserslautern, Germany
Date: Fri, 16 Oct 1992 12:54:31 GMT

vaarisko@tnclus.tele.nokia.fi writes:

> Does anyone know a good algorithm for a 'diskette-filling' program?
> The algorithm should find a subset of a set of numbers (=file sizes)
> the sum of which is closest, but not bigger, than a given number (=disk
> space left) ie. kind of a 'best-fit' algorithm..

(Put this to the TeX.)

Let me paraphrase the problem a little.  You are given a multiset $S$
of numbers, $S = \{ s_1, \dots, s_n \}$, where each $s_k$ is an
integer strictly greater than zero.  The $s_k$ represent your file
sizes. (The multiset is needed so that there may be duplicates, which
cannot be done with an ordinary set.)  You are also given a number
$N$, which plays the role of your disk capacity.  What you want to
compute is a set of indices $I = \{i_1, \dots, i_k\}$ such that

$$
	\sum_{i \in I} s_i \le N,
$$

\noindent and for any other index set $I'$, either

$$
	\sum_{i \in I'} s_i \ge N,
$$

\noindent or

$$
	\sum_{i \in I'} s_i \le \sum_{i \in I} s_i.
$$

(If that's not what you were thinking about, don't bother with the
rest of this article; I have misunderstood you in this case.)

Now, one optimal choice for $I$ would be to choose the indices such
that the threshold $N$ is exactly reached.  There may be more than one
such index set, but ignore that for a minute.

This problem of computing such an index set, or else proving that no
such set exists, is known in the literature as the ``integer knapsack
problem''.  Of course, such a set can be computed, but this will be
very difficult in general.

In fact, the integer knapsack problem has been proved to be
NP-complete, which (among other things) means that it is possible to
prove in polynomial time if a given set of numbers satisfies your
constraints, but that no fast method is known how to get at that set
in the first place.  The best known algorithms for NP-complete
problems require exponential time, and it will stay that way until
someone proves that P = NP by solving any NP-complete problem in
polynomial time.

A special case of the integer knapsack is easy to solve but unlikely
to occur in your application:  Let the file sizes $s_1, \dots, s_n$
be sorted in ascending order.  If you have

$$
	\sum_{j=1}^{k} s_j \le s_{k+1},
$$

then the problem is trivial to solve using a largest-fit strategy:
take the largest $s_{i_1}$ that is smaller than $N$, then take the
largest $s_{i_2}$ that is smaller than $N - s_{k_1}$ and so on, until
you reach a minimum.

So if you solve this problem in polynomial time, you will become very
famous.

Hope this helps.

-- 
Stephan <neuhaus@informatik.uni-kl.de>
sig closed for inventory.  Please leave your pickaxe outside.
PGP 2.0 public key available on request.  Note the expiration date.
Newsgroups: comp.programming
From: walls@saifr00.cfsat.honeywell.com (Gerald Walls)
Subject: Re: Is a generic finite state machine engine reasonable?
Organization: Honeywell Air Transport Systems Division
Date: Wed, 14 Oct 92 15:05:54 GMT

I'm not working directly with Loren, but probably he would want
AFLEX, which generates Ada.  I'm not confident that it would work
very well for the stuff we do here, though.  I think too much stuff
would have to be done to cram stuff into the format that a Lex
engine wants.
From: hartman@ulogic.UUCP (Richard M. Hartman)
Newsgroups: comp.programming
Subject: Re: NO NUMBERS! (or even SHORT INTS!)
Date: 8 Oct 92 17:41:44 GMT
Organization: negligable

oops. typo of my own, that last bit should read:
	"would set i2 to the value of 9"

not i7....

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Lazy day, Sunday afternoon.			|
Like to get your feet up, watch TV.		|	-Richard Hartman	
Sunday roast is something good to eat,		|	hartman@uLogic.COM
must be lamb to day 'cause beef was last week!	|
From: Berend.de.Boer@p23.f112.n100.z60.wlink.nl (Berend de Boer)
Newsgroups: comp.programming
Subject: Barcode: MSI or "Modified Plessy"
Date: Thu, 08 Oct 1992 17:04:00 -0100

Hello reader,

We are working on a barcode-project. We work with the barcode standard
"Modified Plessy" or MSI. This standard uses a checksum after the
barcode is generated. This chechsum are the last two digits (before
the stopbit).
Unfortunately we have not been able to find the algorithm to generate
this checksum. Can anybody please help us?

Greetings, ...... === Ent ===

Newsgroups: comp.programming
From: mjs@hubcap.clemson.edu (M. J. Saltzman)
Subject: Re: C programing
Organization: Clemson University, Clemson SC
Date: Thu, 8 Oct 1992 15:23:26 GMT

In article <1992Oct7.204027.5598@netcom.com> pdh@netcom.com (Phil Howard ) writes:
>ratner@ficus.cs.ucla.edu (David Ratner) writes:
>
>>ai686@cleveland.Freenet.Edu (Ishaq Syed) writes:
>>
>>>I am highschool student..and I would like to request a book that
>>>would teach me C in a si,mple way.  All the books I have incountered
                         ^^^^^^^^^^^
>>>so far have been very complcateed.  I would like a name of a book that
>>>is good for self learning people.  The place I can buy the book would also 
>>>be nice.  Thank you very much.
>>
>>Book:  K&R.  (Kernighan and Ritchie - "The C Programming Language").
>>Place: bookstore.
>
>Another possibility is Harbison and Steele - "C: A Reference Manual".
>Place: same as above

IMHO, neither of these books fill Ishaq's needs.  Yes, K&R is generally
well-written (and I learned C from K&R1), but it's not the book for
novice programmers.  In the preface to K&R1, they write: "This book is
not an introductory programming manual."  And I wholeheartedly agree.

H&S is exactly what the title says it is: a *reference manual*.  Using it
well requires that you already be a knowledgeable C programmer.  Using
it to learn C is hopeless.

Now, having said that, I don't really have a recommendation for an
introductory text in C, since I didn't learn it at that level, and I
don't have any books like that on my bookshelf.  However, I have heard
fairly high net.praise for _C:_A_Software_Engineering_Approach_, and
for Kelley & Pohl's _A_Book_on_C_.

I'm not even sure it wouldn't be a better idea to learn a less
dangerous language (like Pascal) first.  (C is sort of the straight razor
of classical programming languages--it gives a close shave, but you can 
cut yourself really easily!)

-- 
		Matthew Saltzman
		Clemson University Math Sciences
		mjs@clemson.edu
Subject: (no subject given)
Date: Sat, 10 Oct 92 13:07:01 -0400
From: news@cc.swarthmore.edu
Newsgroups: comp.society

Newsgroups: comp.society
From: plummer@cs.swarthmore.edu (David Barker-Plummer)
Subject: Re: net.views -- computer crime
Organization: Swarthmore College, Swarthmore, PA
Date: Sat, 10 Oct 1992 18:06:53 GMT

In article <1992Oct02.211324.12465@utoday.com> wagner@utoday.com (Mitch Wagner)
 writes:

MW> Do you consider computer crime to be a threat to your system?


MW> This question is being posted to gather responses for a regular
MW> opinion column in OPEN SYSTEMS TODAY called "net.views."

MW> By posting a response to this topic, you are granting
MW> permission for OPEN SYSTEMS TODAY to publish your response. A
MW> compilation of the responses to this post will be posted here about
MW> two weeks from today.

MW> Please include in your response your name, your employer, your job
MW> title, and location. Or, if you identify yourself as a student, please
MW> give your class standing (freshman, sophomore, junior, senior, grad),
MW> the school and its location. Please also provide a telephone number
MW> where you can be reached during the daytime (overseas readers note:
MW> that's daytime in North America).

MW> Please be brief; try to limit your responses to two screens
MW> (24x80) of text, not including headers and other administrivia.

MW> Thanks!

MW> -- mitch w.
MW> --
MW> Mitch Wagner, senior editor, Open Systems Today
MW> 2353 Massachusetts Ave. Suite 47, Cambridge, MA 02140
MW> wagner@utoday.com  (617)547-8485  CIS:70212,51  GEnie:MITCH.WAGNER
MW> For subscription information, please call 516/562-5882

So let me get this straight.  You are soliciting information from the
net.community at no cost to yourself, so that you can sell this
information as part of your magazine?

This sounds to me like a commercial use of the net, which (as I
understand it) is prohibited by the rules of NSFnet which forms part
of the Internet on which this post is distributed.

Even if it weren't prohibited, don't you think that asking people to
work for you without compensation is a tad unreasonable?

-- Dave

[Moderator's comment: I approved this posting despite the semi-commercial
nature of the OPEN SYSTEMS appeal because a promise to post result to
the net was included.  Also, net users will be able to make their own
conclusions about the response rate and copyright issues - if their are
few responses, will it be due to unwillingness to "work for nothing" or
simply a reflection of low interest in this forum?  If results are not
posted as promised, it will be the last such posting from OPEN SYSTEMS.
---
Greg Welsh, moderator, comp.society
Internet:  Socicom@american.edu
Bitnet:    Socicom@auvm.bitnet ]
From: wagner@utoday.com (Mitch Wagner)
Newsgroups: comp.society
Subject: net.views -- computer crime
Date: 2 Oct 92 21:13:24 GMT
Organization: Open Systems Today


                 Do you consider computer crime to be
                 a threat to your system?


     This question is being posted to gather responses for a regular
 opinion column in OPEN SYSTEMS TODAY called "net.views."

     By posting a response to this topic, you are granting
 permission for OPEN SYSTEMS TODAY to publish your response. A
 compilation of the responses to this post will be posted here about
 two weeks from today.

     Please include in your response your name, your employer, your job
 title, and location. Or, if you identify yourself as a student, please
 give your class standing (freshman, sophomore, junior, senior, grad),
 the school and its location. Please also provide a telephone number
 where you can be reached during the daytime (overseas readers note:
 that's daytime in North America).

     Please be brief; try to limit your responses to two screens
 (24x80) of text, not including headers and other administrivia.

     Thanks!

                         -- mitch w.
--
Mitch Wagner, senior editor, Open Systems Today
2353 Massachusetts Ave. Suite 47, Cambridge, MA 02140
wagner@utoday.com  (617)547-8485  CIS:70212,51  GEnie:MITCH.WAGNER
For subscription information, please call 516/562-5882
From: 9138827a@ntx.city.unisa.edu.au (Bronwen Strong)
Newsgroups: comp.society
Subject: Telecommuters, Remote Workers
Date: 9 Oct 92 03:21:18 GMT
Article-I.D.: ntx.9210080803.AA01534

I am undertaking postgraduate study at the School of Library and
Information Management, University of South Australia, Adelaide, on
the particular information needs of telecommuters - those who perform
job-related work at a site away from an organisation and communicate
electronically rather than commuting physically.

I would be very interested in, and would greatly appreciate a response
from those who are telecommuters, to the following questions. If you
are not a telecommuter but know of others who are it would be
appreciated if you could pass this on to them:


Q1      Does the organisation to which you telecommute provide any
        library and information services which are accessible to you
        online? (eg catalogs, reference assistance, databases, literature
        searches, document delivery services, organisation information
        such as daily bulletins and administrative gazettes.)

        If yes:

        (a) What services are provided?
        (b) How useful are these services to you?

A1

Q2      What is the nature of the organisation to which you
        telecommute?

A2

Q3      What are the particular information needs that you have as a
        telecommuter?

A3

Q4      What basic information services do you consider should be
        provided by an organisation for its telecommuters? (see Q5 for
        additional and desirable services)

A4

Q5      What additional information services would you perceive as being
        highly desirable for an organisation to provide for its
        telecommuters?

A5

Q6      Are there any further comments you wish to make regarding the
        information needs of telecommuters?

A6

Q7      Would you like a summary of the results of this survey E-mailed
        to you?

A7

Respondents can be assured that individuals and organisations will not
be identified in any report or summary of this survey.

Please E-mail your response to my Internet address:

9138827a@ntx.city.unisa.edu.au

Thank you for your cooperation

Bronwen Strong