RE: On the subject of zero

[Lufkin Brad]

the semi-colon is on the next line!

-Original Message-
From: Fernando Cabral [mailto:[EMAIL PROTECTED]
Sent: Wednesday, December 29, 1999 11:25 AM
To: Dave Bell
Cc: sundial@rrz.uni-koeln.de; Slawek K. Grzechnik
Subject: Re: On the subject of zero




Dave Bell wrote:

>
> Or:  a ^= b ^= a ^= b

Compilor error: line 0 - semicolon missing

Just to take us back to the 0 issue :-)

- fernando


--
Fernando Cabral Padrao iX Sistemas Abertos
mailto:[EMAIL PROTECTED]  http://www.pix.com.br
Fone Direto: +55 61 329-0206mailto:[EMAIL PROTECTED]
PABX: +55 61 329-0202   Fax: +55 61 326-3082
15º 45' 04.9" S 47º 49' 58.6" W
19º 37' 57.0" S 45º 17' 13.6" W

Arrows of Time

[Richard Langley]

The Royal Institution Christmas Lectures this year are on time.  They are
being broadcast on BBC television and the BBC have put up summaries of the
lectures along with a lot of background information on their Web site.  Even
though primarily intended for a younger audience, the pages are worth a look.
Even an item on sundials.  The main page is
.

=== 
 Richard B. LangleyE-mail: [EMAIL PROTECTED]  
 Geodetic Research Laboratory  Web: http://www.unb.ca/GGE/
 Dept. of Geodesy and Geomatics EngineeringPhone:+1 506 453-5142  
 University of New Brunswick   Fax:  +1 506 453-4943  
 Fredericton, N.B., Canada  E3B 5A3
 Fredericton?  Where's that?  See: http://www.city.fredericton.nb.ca/
=== 

And Another BBC Item: Greenwich Electronic Time!

[Richard Langley]

See 

for a news item on Greenwich Electronic Time to be launch on New Year's Day.

=== 
 Richard B. LangleyE-mail: [EMAIL PROTECTED]  
 Geodetic Research Laboratory  Web: http://www.unb.ca/GGE/
 Dept. of Geodesy and Geomatics EngineeringPhone:+1 506 453-5142  
 University of New Brunswick   Fax:  +1 506 453-4943  
 Fredericton, N.B., Canada  E3B 5A3
 Fredericton?  Where's that?  See: http://www.city.fredericton.nb.ca/
=== 

Re: On the subject of zero

[Charles Gann]

-Original Message-
From: [EMAIL PROTECTED] <[EMAIL PROTECTED]>
To: sundial@rrz.uni-koeln.de 
Date: Tuesday, December 28, 1999 5:57 PM
Subject: Re: On the subject of zero


>I just had an interesting thought in regard to the conversation about
zero...
>Nothing is something!
>

How about this:

Three apples (plural)
Two apples (plural)
One apple (singular)
Zero apples (plural) Plural means more than one; therefore zero is more
than one.  ;)

Charlles

Re: On the subject of zero

[Dave Bell]

On Wed, 29 Dec 1999, Fernando Cabral wrote:

> As to the loop, it seems things like
> 
> for ( ; n ; ++n)
> 
> mistifies more than any otherthing with the probable exception
> of things like
> 
> a = a ? b : c;
> 
> - fernando

Or:  a ^= b ^= a ^= b

Dave

RE: On the subject of zero

[Dave Bell]

D'oh!!

On Wed, 29 Dec 1999, Lufkin Brad wrote:

> the semi-colon is on the next line!
> 
> -Original Message-
> From: Fernando Cabral [mailto:[EMAIL PROTECTED]
> Sent: Wednesday, December 29, 1999 11:25 AM
> To: Dave Bell
> Cc: sundial@rrz.uni-koeln.de; Slawek K. Grzechnik
> Subject: Re: On the subject of zero
> 
> 
> 
> 
> Dave Bell wrote:
> 
> >
> > Or:  a ^= b ^= a ^= b
> 
> Compilor error: line 0 - semicolon missing
> 
> Just to take us back to the 0 issue :-)
> 
> - fernando
> 
> 
> --
> Fernando Cabral Padrao iX Sistemas Abertos
> mailto:[EMAIL PROTECTED]  http://www.pix.com.br
> Fone Direto: +55 61 329-0206mailto:[EMAIL PROTECTED]
> PABX: +55 61 329-0202   Fax: +55 61 326-3082
> 15? 45' 04.9" S 47? 49' 58.6" W
> 19? 37' 57.0" S 45? 17' 13.6" W
> 

Re: On the subject of zero

[Fernando Cabral]

Slawek


I know what you mean. For about 10 years I made my living
either teaching C programming language or using it to
replace assembly code or -- less commonly -- to develop
application. This used to be the original, bare-bone K&R C.

Or  -- as in the time of CP/M (do you remember?) -- I used
a still-simpler compiler: BDS-C (BD stands for Brain-damaged
or something like that.

As to the loop, it seems things like

for ( ; n ; ++n)

mistifies more than any otherthing with the probable exception
of things like

a = a ? b : c;

- fernando


"Slawek K. Grzechnik" wrote:

> In computer related fields zero is used ruthlessly up to a point of
> counting pages.
> Non-programmer calls his programmer friend and tells him
> - I faxed you 10 pages of my recent paper
> The other guy starts counting 0,1,...,9 and calls back
> - only 9 arrived
> This is a joke of course playing the trick of so called "fence post error".
>
> In C/C++ a loop on n is an idiom
>
> for( i = 0; i < n; i++ ) {
> .
> }
>
> which fits very well array indexing and pointer arithmetics.
>
> if you see in the code a loop like
>
> for( i = 1; i <= n; i++ ) {
> }
>
> then you have to study the code carefully because probably the author had
> something special in mind or else he was a fool. Note that from the point
> of view of number of iterations both loops are equivalent ("less than n" in
> first loop, "less or equal n" in the second).

--
Fernando Cabral Padrao iX Sistemas Abertos
mailto:[EMAIL PROTECTED]  http://www.pix.com.br
Fone Direto: +55 61 329-0206mailto:[EMAIL PROTECTED]
PABX: +55 61 329-0202   Fax: +55 61 326-3082
15º 45' 04.9" S 47º 49' 58.6" W
19º 37' 57.0" S 45º 17' 13.6" W

Re: On the subject of zero

[Fernando Cabral]

Dave Bell wrote:

>
> Or:  a ^= b ^= a ^= b

Compilor error: line 0 - semicolon missing

Just to take us back to the 0 issue :-)

- fernando


--
Fernando Cabral Padrao iX Sistemas Abertos
mailto:[EMAIL PROTECTED]  http://www.pix.com.br
Fone Direto: +55 61 329-0206mailto:[EMAIL PROTECTED]
PABX: +55 61 329-0202   Fax: +55 61 326-3082
15º 45' 04.9" S 47º 49' 58.6" W
19º 37' 57.0" S 45º 17' 13.6" W

PostScript cylinder dial corrected

[john hoy]

Dear Dialists,

My PostScript cylinder dial program (http://www.cyberspace.org/~jh/dial/)
was, it pains me to say, wrong. Sorry. I hope nobody used it to determine
the time of anything more important than lunch. If you downloaded it
before xmax eve please recycle it and download a new one.

On the bright side, I think it's fixed now. Thanks to Fer de Vries for his
website with lots of detailed formulas and thanks to the rest of you for
your inspiration and stimulation, especially Luke Coletti, Robert
Twilliger and John Carpenter. 

The cylinder dial program is general, that is, it will draw a plan for
differant sized cylinders, however the default values and instructions are
specificly for a common soup can. I'm aiming for the widest possible
target I can and trying to put sundials into the hands of anyone and
everyone who has even a passing interest so I'm trying to use the most
commonly available materials I can think of. 

The main hurdle that stands in my way is the relative unpopularity of the
PostScript format. Although I happened into PostScript programming quite
by accident I've come to appreciate it's incredible power. Even if
PostScript is a bit daunting at first once you learn it it makes so many
things easy. What's more, it's a really interesting mixture of high level
structure and low level control.

Adobe's PDF is, of course, the natural choice for maximizing the potential
audience for a document. Adobe Acrobat Reader comes with win98 (at least
mine did) and PDF has been adopted by the US government for tax forms,
etc., so it really has become the standard file format for those who need
exact control of how their document comes out on various systems.

PDF is derived from PostScript. Actually they say it's a subset of
PostScript. Turning a PostScript file into PDF includes "unrolling" loops,
so a PDF version of a PostScript file can be considerably bigger.
Since they are so closely related it would seem that converting to PDF 
would be pretty straightforward but that isn't exactly the case. Adobe has
an expensive "distiller" that does the conversion and the freely
downloadable ghostscript does it too but that seems to be it. I think the
reasons for this are primarily economic rather that technical. Adobe has
a privatly controlled defacto standard.

My problem is that tripod.com, which gives me my free cgi hosting, only
allows Perl cgi scripts because of the security risk introduced by shell
scripts and neither ghostscript or distiller are Perl. Another problem is
the fact of irritating advertisements and cookies at tripod. On the other
hand, if anyone wants to fool around with perl cgi programs on the web
they have it set up so you don't have to have your file permissions or
shebang lines right and it will still work, which helps.

But I guess I'm pretty far off topic. Happy new year.

John