dikini.net

More binary and interpolation search in haskell

by vlado on Thu, 2009-11-19 16:00

The array code in the previous post on binary search in haskell is messy. Mostly due to my lack of style and the use of arrays, which add a layer of indirection and bounds checks.

This time, I'm going to rewrite the examples to be slightly more readable and I'll implement a linear interpolation search routine. The latter could be handy if function evaluation or array access (access to data on disk?) are relatively slow, and the data is sorted and relatively linear. Although the implementations could be coded even tighter, with less checks, I skip that optimisation for the sake of readability.

Binary search - haskell arrays

by vlado on Thu, 2009-11-05 17:04

I've been looking more into haskell, as part of some personal projects. There I need some constant array like structures, that is ones which have integer indexing and there are some long winded reasons I'm not using a Map. As a first step I've decided look at haskell arrays, by writing some search functions. It is mostly a syntax exercise.

Karmic Koala on Aspire One

by vlado on Thu, 2009-11-05 10:15

Ubuntu Karmic Koala is out for a bit. I've been running it for a week on my Aspire One netbook and so far have only good impressions.

The distribution upgrade went smoothly. I'm not surprised. Its Debian genes show reliability of upgrades. Yes, there were reports of upgrade problems on the interwebs, but so far as I understand they were related to binary blobs, i.e. closed source drivers and such, which is not surprising - it is hard to figure out whose responsibility it is to make them work properly - the infrastructure of a linux distro is very different from that of Windows or Mac OS X. It is unclear whose job it is to do trigger the updates if they were not handled by the default install in the first place - it is a very murky territory usability wise. But that is becoming a rather off-topic rant.

Micro-benchmarking php streams includes part 2

by vlado on Wed, 2009-10-28 15:45

In part 1 I've reported the results of a micro-benchmark designed to compare the performance of plain php includes vs includes via streams from a sqlite database. In this post I extend the test cases with two more no-includes same work, to serve as a base case and includes from a mysql database, the code is the same as in sqlite case, the connector differs. You can find the code attached at the end previous post.

Overall, having in mind the random factors like netbook load (CPU and IO), the differences between the different test cases are insignificant on the test machine - Acer Aspire One netbook.

Please let me know if you decide to run these benchmarks. I will be especially interested to see what are the differences.

These results are encouraging enough to merit developing a more substantial test. I'm interested in benchmarking drupal. What scenarios would you suggest?

There is still a war going on

by vlado on Tue, 2009-10-27 12:14

The task of the first-class University, however, is absolutely clear. Industry being its customer, consultancy must tell industry what it wants to hear; it is the task of the first-class University to tell industry what it does not want to hear, whereby it is the rôle of its scientific authority to ensure that the sting of the academic gadfly really hurts.

In my experience —gathered on different continents—, it is impossible to completely prevent all snake oil peddling on campus, but by openly despising it one can at least save the integrity of the academic enterprise as a whole.

from There is a war going on by E.W.Dijkstra

I recommend reading this essay.

Micro-benchmarking php streams includes from database vs standard includes

by vlado on Sat, 2009-10-24 10:21

During the drupal plugin/update manager discussions I had an aha moment. One of those weird and wonderful ideas came back to me. What if most of the code lived in the db? One would be able to arrange the co-habitation of several concurrent versions of the same website relatively easy. Backups would mean database backup.

Funnily enough, this can help two opposite (scale-wise) types of users - the bottom end, cheapest or free hosting ones and the load balanced crowd.

Why "back"? Well... I had this idea ever since the user streams appeared in php, version 4.3 or there abouts, but it just nestled cosily in the back of my mind, waiting for love, the shy little thing.

Portfolio

by vlado on Mon, 2009-10-12 09:46

This is a list of projects and websites I've worked on recently. It is in no way a comprehensive one, just some of the work I've done over the past few years. For each of the projects I try to give a summary of my involvement and responsibilities. All of the projects used drupal as a primary web engine.

Read more

London Calling - DrupalCon 2011

by vlado on Thu, 2009-10-08 10:43

The London drupal community has thrown a bid into the hat to host DrupalCon 2011. It is a strong bid from a strong team for one of the best cities in the world. So just vote in the poll The preferred venue is Southbank Centre. It tickles me silly to just compare that to a leg of lamb. Don't ask. Ok. Fine. won't be that cruel. Just imagine a pub and food - that's one memory from the first Drupal meet in London. And now Southbank...

There are community polls out on g.d.o for DrupalCon2010 and DrupalCon2011 in Europe. These polls do matter, but are not deal breakers. They are there to reflect the community preference.

And just one last note - I would love Berlin for 2010. I love that city, especially East Berlin. Sorry Copenhagen =(

The design of dikini.net

by vlado on Fri, 2009-10-02 15:17

This website is built on drupal - a content management system extraordinaire. Until the start October 2009 it used to be based on a modded version 4.6, but I upgraded it to the latest release, as part of my 'looking for a job and pimping my assets' project. Now it is just a vanilla Drupal with a custom theme. A variation of the theme I created for the South Wales Linux User Group as currently seen on http://beta.swlug.org

the new look theme

It is based around a grid "theory", to enforce some regularity and rhythm. The base for maintaining the vertical rhythm is 12px font/18px line height. The horisontal grid is organised around 6px (0.5em) units and is currently split into 12 columns. This gives enough room to play with in the future. It is a simple two (8/4) column design.

running a conference using openconf

by vlado on Wed, 2009-04-22 10:46

I've been involved in the organisation of a number of scientific conferences over the past few years. For example 4m/ICOMM 2009 (submissions), I*PROMS 2009 (submissions). The conference sites are usually powered by drupal, the submissions using OpenConf. Managing the submission and peer review of papers is a chore, unfortunately, as is often the case, software gets in your way. So here I try to skim over some of the experiences I had with OpenConf - the good and the bad.

I've tested indico, which looks like a very good system, but it is heavy and over-engineered, especially if you want to run a couple of events, and not hundreds or thousands. It might be good for organisations managing a big number of events, but not for us.

After going through a number of trials I've settled on openconf. It was simple. It fitted the current web infrastructure - LAMP. I reckoned, I could eventually integrate it, or simply transfer some of the data into drupal, and maybe even benefit from code reuse. Surprisingly, I ended being both pleasantly surprised and not so.