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Tag: mac

pdfsync

Published April 13, 2005 by lievenlb

I
expect to be writing a lot in the coming months. To start, after having
given the course once I noticed that I included a lot of new material
during the talks (mainly concerning the component coalgebra and some
extras on non-commutative differential forms and symplectic forms) so
I\’d better update the Granada notes
soon as they will also be the basis of the master course I\’ll start
next week. Besides, I have to revise the Qurves and
Quivers-paper and to start drafting the new bachelor courses for
next academic year (a course on representation theory of finite groups,
another on Riemann surfaces and an upgrade of the geometry-101 course).

So, I\’d better try to optimize my LaTeX-workflow and learn
something about the pdfsync package.
Here is what it is supposed to do :

pdfsync is
an acronym for synchronization between a pdf file and the TeX or so
source file used in the production process. As TeX system is not a
WYSIWYG editor, you cannot modify the output directly, instead, you must
edit a source file then run the production process. The pdfsync helps
you finding what part of the output corresponds to what line of the
source file, and conversely what line of the source file corresponds to
a location of a given page in the ouput. This feature is achieved with
the help of an auxiliary file: foo.pdfsync corresponding to a foo.pdf.

All you have to do is to put the pdfsync.sty file
in the directory _~/Library/texmf/tex/latex/pdfsync.sty_ and to
include the pdfsync-package in the preamble of the LaTeX-document. Under
my default iTex-front-end TeXShop it
works well to go from a spot in the PDF-file to the corresponding place
in the source-code, but in the other direction it only shows the
appropriate page rather than indicate the precise place with a red dot
as it does in the alternative front-end iTeXMac.

A major
drawback for me is that pdfsync doesn\’t live in harmony with my
favorite package for drawing commutative diagrams diagrams.sty. For example, the 75 pages of the current
version of the Granada notes become blown-up to 96 pages because each
commutative diagram explodes to nearly page size! So I will also have to
translate everything to xymatrix&#
8230;

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squeezebox

Published January 25, 2005 by lievenlb


This week I finished the first phase of my home-network plans : from
every computer one can stream iTunes-music files to be played in
the living room, and from every computer one can stream iPhoto or
iMovie-files to the TV-set. Both solutions involve new hardware
and as it usually is with hardware : there are elegant or clumsy
solutions. The photo-video solution is rather clumsy so I’ll postpone
it until later. The audio-solution on the other hand is extremely
elegant : I bought a squeezebox from slimdevices.
It is extremely small (22cmx5cmx12cm) so you can place it virtually
everywhere, it can be connected to your network either wireless or by
ethernet and it has several alternatives to connect to your speakers or
hifi-set : a headphone mini-jack (which is at the moment what I use to
connect it to a pair of powered speakers) but I can always upgrade my
listening experience using : analog audio RCA, digital optical or
digital coax. The service it provides is excellent, all information is
available from their website (they do not ship a CD but you can download
the latest version of slimserver from the website (available for all
platforms)) and they have several forums among which a rather enthusiastic
users-forum (no surprise to me). You get it running in no time. First
download slimserver and install it on the machine(s) containing music
you want to stream over the network. What it does is to add one extra
item to your SystemPreferences and clicking it you can start the
SlimServer. Then, power up the squeezebox and
follow the messages on the display. I choose to connect to a wireless
network, it then detects the names of the possible networks and asks you
to choose one, asks what type of encryption it uses (for Airport b take
64 bit, for g take 128 bit encryption). The most difficult part is to
type in the wireless password as it wants the hexadecimal
equivalent of your pass phrase. To find it, open up Airport Admin
Utility, log in to the network you want and on the screen you get
look for the password icon, clicking it will give you the
hexadecimal WEP-key. If you are familiar with SMS you’ll find it easier
than me to type this in to the squeezebox
(use the number keys to simulate a keyboard). After this it will connect
to your network and get the IP-address of the SlimServer (the computer
on which you started the server) and you have access to its
iTunes-library. Two caveats : make sure you use the MP3-option to
get CD’s into iTunes (the default setting of Preferences/import
is AAC not MP3 (btw. slimdevices now claim that you may also use
AAC-files, I didn’t check this out yet but have no doubts it will
work). The second is that the display screen is rather small to browse
the library if you are used to iTunes’ window. A neat way around it is
to use a webbrowser on ANY computer in your network (for example the
iBook on your lap). Just fire up Safari and go to the
Rendezvous-window (it took me some time to figure out what they
meant by it : in Safari go to the Bookmarks pulldown menu, then
choose Show all bookmarks and on this page you will find a
Rendezvous-tab, click it and one of the bookmarks will be
SlimServer and by clicking on it you have web-access to control
your squeezebox. Very neat, this Rendezvous
awareness and a sharp contrast to the clumsy photo-video solution. So,
if you want to free your music and hear it via hifi-standards rather
than via computer-soundcards go and buy as many squeezebox sets as you will need to fill your house with
music!

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ISBN prefix

Published December 27, 2004 by lievenlb

How to sell
modular arithmetic to students only interested in literature? Well, try
to explain the structure of ISBN-numbers
“The ISBN (International Standard Book Number) is a unique
machine-readable identification number, which marks any book
unmistakably. This number is defined in ISO Standard 2108. The number
has been in use now for 30 years and has revolutionised the
international book-trade. 166 countries and territories are officially
ISBN members. The ISBN accompanies a publication from its production
onwards.” The ISBN-number of a book is a ten-digit number divided into
four parts, separated by hyphens telling you a lot about the ambitions
and location of the book’ publisher. I’ll explain some of it by
telling how I obtained the barcode for the first book to be published by
neverendingbooks.org (see
picture). The first part is the group
identifier and identifies a country, area or language area
participating in the ISBN system. For the Netherlands and the Flemish
speaking part of Belgium this identifier is 90. Hence,
depending on your location you have to approach different agencies in
order to obtain an ISBN-number. If you are living in the US all you have
to do is to invent a name for your PublishingHouse, get your Visa-card
out and visit isbn.org
. For smaller groups the process is more personal. The first time I
tried to apply for an ISBN-number with De Boekenbank I
messed up and got immediately an email telling me what I did wrong. I
replied explaining what NeverEndingBooks had in mind and asked advice on
how to set it up properly. I’m sure I’ll need this personal contact
again in the near future. The second part is the _Publisher
Identifier_ or _prefix_. I didn’t know this before but the
very definition of a _publisher_ is the person or company
registering a book’s ISBN. Hence, if you intend to publish a series of
books your local ISBN-agency has to reserve a certain amount of
ISBN-numbers for you, all having the same start-block (the prefix). The
shorter the prefix the more ambitious the PublishingHouse. The
registered prefix of NeverEndingBooks is 90809390 which
tells the experienced ISBN-watcher that we intend in the next years to
publish “only” ten books. If you have more energy you can also apply
for a series of 100, 1000 or even 10000 ISBN-numbers but the amount of
money needed to register these series increases quickly… The third
part of the ISBN-number is the _title identifier_ so for our
first book it is just 1. However, in order to register
it you have to provide the agency (minimally) with a title and
publication date (fortunately, author, price, number of pages etc. are
optional at this stage). Anyway, the first real deadline for
NeverEndingBooks will be may 15th 2005! And now it is time to return
to modular arithmetic, the fourth part is a _check digit_. The
check digit is the last digit of an ISBN. It is calculated on a modulus
11 with weights 10-2, using X in lieu of 10 where ten would occur as a
check digit. This means that each of the first nine digits of the ISBN
excluding the check digit itself is multiplied by a number
ranging from 10 to 2 and that the resulting sum of the products, plus
the check digit, must be divisible by 11 without a remainder. In our
case, we have the following numbers(weights) 9(10) 0(9) 8(8)
0(7) 9(6) 3(5) 9(4) 0(3) 1(2) We have to multiply the numbers
with their weight and add them all up,
90+0+64+0+54+15+36+0+2=261=8(mod 11) whence the check
digit should be 3. For example, I know already that the
ISBN-number of the second book to be published by NeverEndingBooks will
be 90-809390-2-1 but, due to lacking information, it will take a while
before it can be registered.

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