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Tag: geometry

upgrade to wp 2.0

All
activity on this site this week (apart from changing the theme) was done
behind the scenes. Finally, _neverendingbooks_ is upgraded to WordPress 2.0.
It is a straightforward well-explained procedure but somehow I decided
to try this out in between a WorkShop and a
Ph.D. defense. As a consequence I had to reclone twice…
Some of the Plugins‘ functionality
didn’t survive the upgrade. In particular, the anti-spam plugin BotCheck doesn’t work any longer (one could fill out any code and
still get a reply posted) as I found out sunday-morning when I was
greeted with about 20 spam-replies… Fortunately, WP 2.0 comes
bundled with its own anti-spam plugin Akismet but one needs a WordPress.com API key which
meens signing up to a WordPress-account (free). When Akismet is
activated, it really bans all spam (it even shows how many spam-messages
it found, 30 over two days…), the only problem being that it seems
to de-activate itself at random… The new theme is called Kiwi which is a lot more
compact than the default neverending(sic) page. But there is a (heavy
some will say) price to pay : only summaries of posts are on the
front-page and the font is (too some will say) small. Still, Kiwi has
some nice extra features : the Featured Post Plugin which
allows to re-cycle changing selected old posts to the right of the
banner. Another changing part is the _Elsewhere_ list (second row
to the right) where one can display any feed. At the moment (but I may
change this as the del.icio.us site
seems to be having some problems) all _del.icio.us_ links tagged
noncommutative are shown (if the site is up…). It
appears that apart from Graham
Leuschke
nobody has a del.icio.us account or doesn’t use the
noncommutative tag. So, if you want to change this site a bit every day,
you know what to do. Speaking of tags, several new
_categories_ were created so that posts now get multiples tags,
describing better their (intended) content. Something I learned by
tagging papers at citeUlike. Btw.
you are still invited to join the
NoncommutativeGeometry Group
over there… Clearly, re-tagging
every individual post was a painstaking experience. A WordPress 2.0
feature I like is the ability to write _pages_ (as opposed to
Posts) which are kept alive in the sidebar and therefore resemble
‘stickies’ (in WP parlace ‘they live outside of the usual
timeline’). At the moment there is just one test-page NAGworldMAP
on which you can see that geocoding was added to
this site via the Geo
Plugin
(allowing to add geographic data to posts) and the instant google world map Plugin plotting these data on a Google Map. At the moment you can see
the distance I have to cycle to get to the university, but I have plans
to do something more substantial with this feature soon, so please
familiarize yourself with dragging and zooming the map (for US-citizens,
European countries often do not put geographic data in the public
domain, so there is a limit to the zoom-factor and I use the
‘satellite’-view rather than any of the other two).

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citeUlike

Thanks
to Andrei Sobolevskii for his comment
pointing me to a wonderful initiative : CiteULike.

What is CiteULike?
CiteULike is a
free service to help academics to share, store, and organise the
academic papers they are reading. When you see a paper on the web that
interests you, you can click one button and have it added to your
personal library. CiteULike automatically extracts the citation details,
so there’s no need to type them in yourself. It all works from
within your web browser. There’s no need to install any special
software.
Because your library is stored on the server, you
can access it from any computer. You can share you library with others,
and find out who is reading the same papers as you. In turn, this can
help you discover literature which is relevant to your field but you may
not have known about.
When it comes to writing up your
results in a paper, you can export your library to either BibTeX or
Endnote to build it in to your bibliography. CiteULike has a flexible
filing system, so you actually stand a chance of being able to find that
article that you stored a few months ago when you need
it.

If all this seems too abstract, here is an excellent practical
introduction
(also suggested by Andrei). This text focusses on
articles from AnthroSource but if you’re a mathematician, do the
same things when you are at the abstract page of a paper on the arXiv or a paper description from MathSciNet. The really nice
thing is that you virtually have to do no typing at all (apart from the
tags you want to add to classify the paper where you want it or, if you
want, to add a note about the paper). Another exciting feature
is that you can upload your personal copy of the paper. A typical
situation : most of us can get the PDF-file of a published paper at work
(because the university has a contract with the publisher) but not at
home, on the road or on vacation. So, while at work, download the PDF,
upload it as your personal copy to citeUlike and you can read that paper
wherever you have internet access! But there is more : you can
export the BibTeX-data of your whole library and use it in your next
paper, every library has its separate RSS-feed so you can feed it to a
news-aggregator (or to bloglines) to find out whether someone with
similar interests added a new paper to his/her library, you can create
Groups that is collections of Libraries of people interested in the same
topic, so that others can help you finding stuff of value (and again,
such Group-libraries have there own RSS-feed so….), all libraries
have all tags used by the Library-owner in a graphical format, the
larger the tag-text the more it is used in the Library, so just by
looking at the right-sidebar you get a good idea what the person’s
interests are, etc. etc. etc. I’m just two days into
citeUlike and there will be tons of features I still have to discover
and I’ll report on this later. At the moment I just added a few
papers to my Library but I will extend this drasticly in the weeks
ahead. If you want to check on my progress here is lieven’s Library
or the citeIlike link in the header of this blog (between the
‘about me’ and the ’search’ link) and I hope
that many of you will add similar buttons on your homepages.
Finally, if you are interested in Noncommutative algebraic and/or
differential geometry, I’ve set up a Group-Library
NoncommutativeGeometry
. At the moment it’s just identical to
my own Library, but please register to citeUlike, set up your own
Library and if you’re into NOG join this group!

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Latexrender and dvonn boards

In order
to blog a bit about Dvonn-strategy, I made myself a simple Dvonn
LaTeX-template which works very well on paper but which gets mutilated
by Latexrender, for example the first situation of the looks
like

$~\xymatrix@=.3cm @!C @R=.7cm{ & & \Black{2} \connS & &
\bull{d}{5} \conn & & \bull{e}{5} \conn & & \bull{f}{5} \conn & &
\bull{g}{5} \conn & & \bull{h}{5} \conn & & \SWhite \connS & & \SWhite
\connS & & \SWhite \conneS & & \\ & \bull{b}{4} \conn & & \SBlack
\connS & & \Black{6} \connS & & \bull{e}{4} \conn& & \bull{f}{4} \conn &
& \bull{g}{4} \conn & & \bull{h}{4} \conn & & \SWhite \connS & &
\SWhite \connS & & \SWhite \conneS & \\ \SBlack \connbeginS & &
\SBlack \connS & & \BDvonn{7} \connS & & \bull{d}{3} \conn & & \SBlack
\connS & & \BDvonn{6} \connS & & \bull{g}{3} \conn & & \bull{h}{3}
\conn & & \Dvonn \connS & & \SWhite \connS & & \SWhite \connendS \\ &
\Black{5} \connbeginS & & \bull{b}{2} \conn & & \SBlack \connS & &
\bull{d}{2} \conn & & \bull{e}{2} \conn & & \bull{f}{2} \conn & &
\bull{g}{2} \conn & & \bull{h}{2} \conn & & \SWhite \connS & & \SWhite
\connendS & \\ & & \bull{a}{1} \con & & \bull{b}{1} \con & & \Black{5}
\conS & & \bull{d}{1} \con & & \bull{e}{1} \con & & \bull{f}{1} \con & &
\bull{g}{1} \con & & \bull{h}{1} \con & & \White{2} & &} $

The
reason behind this unwanted clipping is that Latexrender uses
**convert** to take the relevant part of a ps-page containing only the
TeXed formula on an empty page by performing clipping and then converts
it into a GIF-file (or any other format you desire). The obvious way
round this is to enlarge my template by adding two additional rows and
columns and putting visible nonsense there (such as dots) to enlarge the
relevant part so that no clipping is done of essential info. But then
(1) the picture generated becomes even larger than that above and (2) I
don’t want you to see the extra nonsensical dots… The essential line
in the **class.latexrender.php** file is

$command =
$this->_convert_path." -density ".$this->_formula_density.
" -trim -transparent \"#FFFFFF\" ".$this->_tmp_filename.".ps ".
$this->_tmp_filename.".".$this->_image_format;

So
I needed to delve into the [manual pages for the convert command](http://amath.colorado.edu/computing/software/man/convert.html)
of the ImageMagick-package. To my surprise, the *-trim* option (which I
thought to adjust somewhat by adding parameters) doesn’t exist! Still, I
got around my second problem using the *crop* option and around the
first by using the very useful *geometry* option. The latter is also
useful if you find that the size of the output of Latexrender is not
compatible with the size of your regular text. Of course you can amend
this somewhat by using the *extarticle* documentclass (as suggested) but
if you want to further adjust it, use for example

-geometry
86%

to size the output to exactly 86% (or whatever you need).
So, whenever I want to do some Dvonn-blogging from now on I’ll change my
class.latexrender.php file as follows

$command =
$this->_convert_path." -crop 0x0-10% -crop 0x0+10% -density
".$this->_formula_density. " -geometry 80%
-transparent \"#FFFFFF\" ".$this->_tmp_filename.".ps ".
$this->_tmp_filename.".".$this->_image_format;

which
produces the output

$\xymatrix@=.3cm @R=.7cm{.& & & & & & & & & &
& & & \\ & & & \Black{2} \connS & & \bull{d}{5} \conn & & \bull{e}{5}
\conn & & \bull{f}{5} \conn & & \bull{g}{5} \conn & & \bull{h}{5} \conn
& & \SWhite \connS & & \SWhite \connS & & \SWhite \conneS & & & \\ & &
\bull{b}{4} \conn & & \SBlack \connS & & \Black{6} \connS & &
\bull{e}{4} \conn& & \bull{f}{4} \conn & & \bull{g}{4} \conn & &
\bull{h}{4} \conn & & \SWhite \connS & & \SWhite \connS & & \SWhite
\conneS & & \\ & \SBlack \connbeginS & & \SBlack \connS & &
\BDvonn{7} \connS & & \bull{d}{3} \conn & & \SBlack \connS & &
\BDvonn{6} \connS & & \bull{g}{3} \conn & & \bull{h}{3} \conn & &
\Dvonn \connS & & \SWhite \connS & & \SWhite \connendS & . \\ & &
\Black{5} \connbeginS & & \bull{b}{2} \conn & & \SBlack \connS & &
\bull{d}{2} \conn & & \bull{e}{2} \conn & & \bull{f}{2} \conn & &
\bull{g}{2} \conn & & \bull{h}{2} \conn & & \SWhite \connS & & \SWhite
\connendS & & \\ & & & \bull{a}{1} \con & & \bull{b}{1} \con & &
\Black{5} \conS & & \bull{d}{1} \con & & \bull{e}{1} \con & &
\bull{f}{1} \con & & \bull{g}{1} \con & & \bull{h}{1} \con & & \White{2}
& & & \\ . & & & & & & & & & & & & & } $

which (I hope) you will
find slightly better…

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