C[omp]ute

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Always interested in offers/projects/new ideas. Eclectic experience in fields like: numerical computing; Python web; Java enterprise; functional languages; GPGPU; SQL databases; etc. Based in Santiago, Chile; telecommute worldwide. CV; email.

© 2006-2013 Andrew Cooke (site) / post authors (content).

Mapa de Ciclovias en Santiago

From: andrew cooke <andrew@...>

Date: Sun, 19 Oct 2014 16:44:26 -0300

https://maps.google.cl/maps/ms?ie=UTF8&oe=UTF8&t=h&source=embed&msa=0&msid=200859449321945444424.0004936368ca70e20d7c0&dg=feature

Most complete I've seen.

Andrew

Previous Entries

How Unreliable is UDP?

From: andrew cooke <andrew@...>

Date: Thu, 16 Oct 2014 18:24:47 -0300

http://openmymind.net/How-Unreliable-Is-UDP/

Interesting stuff about ordering towards the end.

Andrew

SE Santiago 20m Bike Route

From: andrew cooke <andrew@...>

Date: Sat, 4 Oct 2014 18:35:34 -0300

20 miles (30km) - mainly on cyclepaths!

I'll describe this as I ride it, as a loop from Europa / Lyon, but if you
trace it out on a map then obviously you can start wherever you want.  Also,
since it has a "figure of 8" shape, you can break it into shorter rides.  And
I'll include an additional cyclepath that gives smaller (12m) route.

Starting from Europa / Lyon (or Antunez / Lyon), go S on Lyon (new cyclepath)
to Pocuro.  On Pocuro turn E (cyclepath) and continue to the junction with
Tobalaba.  Here you need to take some care - I cross at the pedestrian
crossing and cycle slowly across the bridge on the footpath - to get to the
other side of the river.  Then travel SE along Sanchez Fontecilla (path shared
with pedestrians for first block, til Bilbao, then cyclepath).

Continue on the cyclepath, following the canal, until the large junction at
Principe De Gales.  Here you need care again - I use the pedestrian crossings
- until you can pick up the cyclepath on the left side of Tobalaba, after the
Metro entrance (so you're heading in the same general direction as before, but
have now swapped to the other side of the canal).  La Canada is best crossed
just after the speedbump before continuing SE on the cyclepath along Tobalaba.

Continue to Larrain (which is now called Alcalde blah blah) and turn left.
There's 10 metres or so on the footpath before the cyclepath starts again.  Go
almost all the way up Larrain.  Near the end, when the gradient is steepest,
the cyclepath stops and you need to share a fairly narrow road with a fair
amount of traffic.  You could probably take the pavement at this point (almost
no pedestrians here).  Good excuse to walk...

Climb until you reach Casanova (bus stop on right) (incidentally, at this
point, if you climb a little more, you get to Parque Mahuida, with some
horse/cycle trails).

Turn right (S) along Casanova.  This is a road, but has only light traffic.
When you reach the apparent end, in a T junction with Talinay, turn left and
climb a little before bearing right, and the road becomes Casanova again!
Keep heading S (crossing an over-complicated junction with Arrieta) until
Diagonal Las Torres.  Cross Torres and you arrive at Grecia.

Turn right and go W down Grecia.  There's a cyclepath on the right (with
parked cars!), which switches to the centre (it's not easy to see, but when it
stops on the right, cross to the centre and then continue to descend on the
right hand of the central park).

Eventually Grecia meets Tobalaba.  The cyclepath stops just before, so you
need to cross back to the right of the road.  At this point, for a little
diversion you can make your way on the right of the canal, but it's a longer
route, and includes some overgrown paths and roads, so it's simpler to cross
the canal and return N along the Tobalaba cyclepath.

Heading NE and NW you retrace some of the route earlier (but only a relatively
short distance, and it's a pleasant path) before arriving back at the junction
Tobalaba / Principe De Gales.  Here, leave the earlier route and instead head
N on Ossa.  There's no nice way to do this - for one block I cycle slowly
along the pavement.

But after that one block you reach Bilbao, and Ossa becomes Vespucio, with a
central park suitable for cycles.  So navigate the junction there and head N,
NW along Vespucio.

Vespucio goes on and on [* shortcut - see below].  Currently there are
construction works near Vitacura, but you can cycle round them.  Continue
through the central park until the path stops, on the right, near a fountain
(IIRC), and just before the bridge over the Mapocho.  To your right you will
see, on the other side of the road, some blue bollards.  CAREFULLY cross the
road here (it's not easy to see oncoming traffic, which is fast).  Go through
the bollards and left, along a quiet street, which turns to the right.

Just after the turn there's a pedestrian crossing.  Turn left on that crossing
and enter the park.  Turn left again, and follow the track on the edge of the
park, going SW and then NW, climbing steeply, and going over a bridge.  Cross
the Mapocho.

On leaving the bridge, descend, bear right and climb again, turning left onto
another bridge, that takes you towards the Parque Metropolitano.  Continue NW
until you reach the road entering the park, turn left, enter, and climb to the
SW.

This is a fairly steep climb, but not as bad as Larrain, so don't worry.
Fairly soon you meet a roundabout.  Bear right (heading roughly W) and
continue to climb (less steeply).  You will reach another roundabout where you
can turn right (heading SW) and descend.  Yay!

Follow the road down to a T.  If you go right here you can go up to the
Virgen, but for now turn left and head E, following a winding road (including
a couple of hairpins) down to the exit of the park, at the top of Pedro de
Valdivia N.

Go S down Valdivia.  This is back on a road, but fairly quiet until the river.
Crossing the river and continuing S on Valdivia is then cycling in busy
traffic - you may want to use the pavement or walk.  But I cycle in the
traffic, and continue S until I get to Europa (just before Antunez).  Turning
left (E) down Europa brings me back to where I live, and the start of the
route.

[*] I said I'd include an additional route that makes things shorter.  From
Vespucio, turn left (W) down Isabel La Catolica.  This is a cyclepath that
takes you back to Pocuro / Tobalaba.

Enjoy!

Andrew

Cameron's Rap

From: andrew cooke <andrew@...>

Date: Wed, 1 Oct 2014 19:55:23 -0300

https://www.youtube.com/watch?v=0YBumQHPAeU

Andrew

Configuring libxml with Eclipse

From: andrew cooke <andrew@...>

Date: Wed, 1 Oct 2014 10:44:06 -0300

In the project settings, under C/C++ General, Paths and Symbols, add
/usr/include/libxml2 to the "includes" tab (or wherever the include file is -
run pkg-config --cflags libxml-2.0)

Goodbye red squiggly underlines!

Also, for my future reference, the station.xml schema web page thing is at
http://www.data.scec.org/xml/station/20110427/stationxml_schema_doc.html

Andrew

Reducing Combinatorial Complexity With Occam - AI

From: andrew cooke <andrew@...>

Date: Sat, 27 Sep 2014 08:50:32 -0300

http://gup.ub.gu.se/records/fulltext/199296/199296.pdf

Having a hard time working out if this is useful or not.  I don't really know
enough context, but it seems obvious.  Is it new?

Andrew

Sentidos Comunes (Chilean Online Magazine)

From: andrew cooke <andrew@...>

Date: Sun, 21 Sep 2014 11:03:16 -0300

http://www.sentidoscomunes.cl/

Looks like some good, serious reporting on local and international issues in
spanish.

Andrew

Hilary Mantel: The Assassination of Margaret Thatcher - August 6th 1983

From: andrew cooke <andrew@...>

Date: Fri, 19 Sep 2014 15:25:25 -0300

http://www.theguardian.com/books/2014/sep/19/hilary-mantel-short-story-assassination-margaret-thatcher

Andrew

NSA Interceptng Gmail During Delivery

From: andrew cooke <andrew@...>

Date: Thu, 11 Sep 2014 08:59:12 -0300

Well, it doesn't actually say that, but...

http://www.cert.org/blogs/certcc/post.cfm?EntryID=206

(I may be jumping to conclusions but this seems pretty big.  I wonder if

Andrew

General IIR Filters

From: andrew cooke <andrew@...>

Date: Sun, 7 Sep 2014 22:48:05 -0300

I just wasted a weekend on this...

When you read about IIR filters they're always drawn in a certain way, as a
rather orderly set of delays, scales, and sums.  It struck me that there must
be a lot more variety if you allow general (directed) graphs.  So I had the
idea to write some Julia code that would evolve filters, using a GA, given a
target response function.  The GA doesn't really "care" that the graphs are
complex, and the hope was to generate much more compact expressions for useful
filters.

Well, the code didn't get that far.  I wrote a few basic data structures and
the routines to generate graphviz plots of the filters (the graphs).  To test
this I decided to define and graph a filter from a DSP textbook.  The most
complicated I could find was in a section that showed how arbitrary
combinations of filters could be reduced to the orderly canonical form...

So by looking for a nice filter to test I found the evidence that what I was
doing was pointless - it doesn't provide anything that the canonical approach
doesn't also provide (well, that's not completely true - it's possible it
might find a way to use less memory space, but there's no possibility for a
"completely new kind of filter").

Ah well.  Live and learn.  At least I wanted to program in my spare time,
which has been unusual this last 6 months or so.

Andrew

What's happening with Scala?

From: andrew cooke <andrew@...>

Date: Fri, 5 Sep 2014 22:36:39 -0400

3 different compilers:

Typesafe (Odersky's company)'s original (canonical scala)
https://github.com/scala/scala

A community fork
http://typelevel.org/blog/2014/09/02/typelevel-scala.html
https://github.com/typelevel/scala
and related HN discussion which I haven't read yet -
https://news.ycombinator.com/item?id=8258255

And now https://github.com/paulp/policy from the guy who did most of the work
on the canonical code.

So, did Scala just implode?

Andrew

Interesting (But Largely Illegible) Typeface

From: andrew cooke <andrew@...>

Date: Mon, 1 Sep 2014 10:48:25 -0400

https://www.behance.net/gallery/19004863/Nihon-Typeface

Andrew