To
a large extent mathematics has to do with elaborate typography. Many
youngsters have been attracted over the centuries to maths because they
wanted to understand the meaning of these beautiful pages filled with
integrals, partial derivatives and other bizarre hieroglyphs. But now we
have come to the point that this obsession for symbols is working
against mathematics…
Have you ever wondered why there are so
few mathematics-pages on the net compared to computer-science pages
(apart from the fact that a lot more exiting things are happening in
web-technology these days than in mathematics), why forums dedicated to
math-problems never get off the ground (apart from boring housework
sites) or why it is so seldom that you discuss serious math with
colleagues or students via emails (apart from the fact that more and
more mathematicians seem to turn off their sharing mode) ???
One of the reasons might be that our default way of writing and
communicating math (LaTeX) is incompatible with either HTML or email
(and for those of you who think that LaTeX2HTML or
tth or similar programs offer an alternative, just
try to make an attractive looking website with them and prove me
wrong).
If we want mathematics to survive and flourish (and
whether you like it or not that may depend heavily on its
web-visibility) it is high time to develop some
ascii-math, that is, a way to write mathematical formulas in
plain typewriter symbols. This cannot be totally impossible as
programming languages are capable of defining a large number of
complicated objects with ascii and for those of you who discard the idea
on beauty-reasons, I never found a piece of code in a computer
book particularly ugly.
Of course I realise that not too many
people will be willing to make this paradigm-shift right now, but can we
at least ask of people introducing new symbols to add as an appendix to
their paper a suggestion for the transition to ascii-symbols for
those who value the net and/or sharing more than they do. Thank
you!
neverendingbooks Posts
Carbon Copy Cloner is a tool to make a full backup
of your hard-disk on an external firewire disk or iPod. Here’s
how it sells itself
Have you ever wanted a simple, complete,
bootable backup of your hard drive? Have you ever wanted to upgrade to
a larger hard drive with minimal hassle and without reinstalling your
OS and all of your applications? Have you ever wanted to move your
entire Mac OS X installation to a new computer? Then CCC is the tool
for you! CCC makes these tasks simple by harnessing the Unix power
built into Mac OS X. In addition to the features that CCC has provided
in the past, version 2 offers synchronization of the source and target
as well as scheduled backup tasks.
I didn’t try it out yet
but was interested in the final sentence and scrolling down the page I
discovered that the synchronisation is done using Dan Kogai’s psync program, which does not seem to work under
10.3 but has on the page a patch to this. Rather than using the
psync-page to install it, one can use the unoffical psync for Panther dmg-file from the
Carbon Copy Cloner-page. It installs without a problem and to
learn how to use it, there is a manual page. Here is what I do when I want to
synchronize my Documents-folder on iMacLieven to the
backup-machine tweedledee over the Airport-network
psync /Network/iMacLieven/lieven/Documents /Users/lieven/docsLieven
Watching the packet-flow on the Activity Monitor it seems to be
slightly quicker than the rsync tool. But most of all : it seems
to do a much better job. When I compared the end-result of the
synchronising session with rsync to that of psync I was
surprised to find a 20 Mb difference (on an original .5 Gb Folder) in
psync‘s favour! But even psync seems to have dropped 0.6
Mb in the process…
Over
the last couple of days I’ve been experimenting a bit with different
backup methods. To begin, I did try out ExecutiveSync and its
successor You Syncronize but they are very, very
slow. Not only did the first synchronizing of a 0.5 Gb Folder between
two computers over our Airport-network took over 2.5 hrs, but also on
subsequent syncs the checking of the database seems to last forever.
So I turned to the fink project
again and did find two interesting packages : wget . GNU Wget is a free network utility to
retrieve files from the World Wide Web using HTTP and FTP, so one way
to backup a folder would be to put it in the Sites folder and
mirror it over the network using wget. I did’t check this out in
great details (did a small test to see it working but I assume it will
be slow for large folders). The other one is rsync It uses the “rsync algorithm” which
provides a very fast method for remote files into sync. It does this by
sending just the differences in the files across the link, without
requiring that both sets of files are present at one of the ends of the
link beforehand. This seems to be precisely what I wanted to do and
after a google for ‘rsync OS X’ I arrived at the RsyncX package which is an implementation of rsync
with HFS support and configuration through a command line (Terminal) or
graphical user interface. I downloaded this package and the GUI seems to
be placed in the Applications/Utilities and tried it out by
filling out the Source and Local Folders and pressing the synchronize
button. Not much progress was reported but the Activity Monitor
showed that it was using up all of the CPU so I was patient for over an
hour and then looked for the Network Activity in the Activity
Monitor and virtually no packets were going in or out, so I killed
RsyncX. I am sure I did something wrong but rather than trying to
get it working, I tried the command-line rsync-command I
downloaded from Fink. After a few false attempts I
typed
/sw/bin/rsync -a -e ssh iMatrixLieven.local:/Users/lieven/Documents /Users/lieven/docsLieven
and suddenly the packets were flying
happily over the network at 250 Kb/sec, so it took me only half an hour
to get a first synchronization done and subsequent changes are added in
no time! Afterwards I discovered that rsync is included in the
standard OS X Developers Tools as RsyncX seems to have replaced
it to rsync_orig and installed a new (quite large) rsync
in /usr/bin. Maybe my problems with RsyncX were caused
because I have /sw/bin earlier in my $PATH than
/usr/bin but verifying this will have to await another day. For
the moment, I’m happy to have a quick syncronizing tool available and
Real Madrid is playing on the TV…