Tag Archives: technology

Bitcoin and the Blockchain

It’s hard to believe that a whole year has passed since I last wrote on the topic of bitcoin, and my remaining 1 bitcoin is worth rather less than it was back then. During the week I presented at the Sydney Financial Mathematics Workshop on the topic of bitcoin, taking a rather more technical look at the mechanics of the blockchain than in my previous posts here on the Mule. For those who are interested in how Satoshi Nakamoto solved the “double spend” problem, here are the slides from that presentation.

Bitcoin and the Blockchain

As part of my preparation for the presentation, I read Bitcon: The Naked Truth About Bitcoin. If you are a bitcoin sceptic, you should enjoy the book. If you are a Bitcoin true believer, you will probably hate it. It is over-blown in parts and gets a few technical details wrong, but I am increasingly convinced by the core argument of the book: the blockchain is an extraordinary innovation which may well change the way money moves around the world, but bitcoin the currency will prove to be a fad.

Mobile coverage

A friend and regular Stubborn Mule reader drew my attention to an article in the Sydney Morning Herald this week about the Australian telco Telstra. Much of the recent commentary has focused on the implications of the national broadband network (NBN) for Telstra. While the NBN certainly gets a mention here too, for me the most striking paragraph deals with the extraordinary success Telstra has been having of late in the mobile phone market:

In the December half, the group added 420,000 bundled customers — customers on bundled deals tend to be “stickier” and stay with a telco longer than those who sign on for only one service — and it added 139,000 retail fixed broadband customers. Most importantly, it added 919,000 mobile phone customers: that’s the biggest mobile phone customer growth Telstra has produced for more [sic] a decade.

Gaining almost 1 million new customers in six months is quite an achievement in a country with a population of around 22 million. My own experience may shed some anecdotal light on Telstra’s success. I switched from Virgin mobile to Telstra late last year. The main reason was network quality. Virgin use the Optus network which I found extremely unreliable, even in central parts of Sydney. Sitting in a café in Glebe with no signal and seeing the person next to me with four bars on a Telstra phone had become too much. Customer service did not come into the decision: as far as I can tell, all the providers are equally atrocious on that score. So that just left price. When I first signed up with Virgin a couple of years earlier, Telstra may have had the superior network, but charged a hefty premium for it. But since then their prices have become far more competitive, which made the decision to switch very easy. I know a number of other people who have switched for exactly the same reason.

Even so, 1 million new customers is an impressive result for such a short period of time. This prompted my source to do some further research. According to a Wikipedia article about mobile phone penetration, in 2006 Australia’s population of 20.8 million owned 19 million mobile phones*. By 2007, that figure had grown to 21.3 million while the population was up to 21.2 million and so there was more than one phone for every man woman and child in the country. I have no doubt that the number of mobile phones has continued to grow faster than the population since then.

But despite over 100% mobile phone penetration, Australia is far from being the country most in love with mobile phones. The chart below uses the Wikipedia statistics to show the top 20 countries and the statistics are intriguing and not a little mysterious.

Top 20 Countries by Mobile Phone Penetration

Montenegro is clearly in the lead with almost two phones per capita. There is a bit of a drop down to Saudi Arabia with a penetration rate of 170%. On 151%, Hong Kong comes in third and leads a closely packed group all close to the 150% mark. Continuing down the list, penetration rates fall gradually down to Chile at 113% which means that Australia does not even make it into the top 20. In fact, even New Zealand ranks higher in 23rd place, while Australia is only in 31st place.

Of course, differences in timing of both the phone and population figures mean that the Wikipedia article will not be very accurate, but the overall picture remains impressive for someone like myself who is old enough to remember a time before mobile phones. And if anyone has any theories why Montenegro has so many mobile phones, please share your theory in the comments below!

* Unfortunately the Wikipedia article cites no source for the 19 million figure. Population statistics are sourced from the Australian Bureau of Statistics.

NBN in more than 140 characters

migNow that Labor has scraped their way back into power, it looks very likely that the National Broadband Network will go ahead in some form or another. Debates on the merits of the scheme continue apace, not least on Twitter, conveniently labelled with the #nbn hashtag. One frequent twitter on this topic, @pfh007, is also a regular commenter here on the Stubborn Mule. It seems that his thoughts on “Fibre to the Home” (FTTH) can no longer be constrained to a mere 140 characters, so he has now written a guest post for the Stubborn Mule.

A friend asked me a few days ago whether I could state my position on the current NBN proposal in 140 characters or less.

Although 140 characters suits my attention span and typing speed, the FTTH NBN proposal requires a few more.

Please note I have no academic, technical or professional background in this area to give weight to my opinion. So take it for what it is – sideline commentary from my IT shed. But first an initial comment about the FTTH NBN debate.

Unlike many commentators, I do not feel that the debate has been sterile or shallow. Certainly, there has been some partisan barracking where views expressed seem to be simply based on what position a person’s political team is taking on the issue, and some commentators have let their passions get the better of their reason, but overall I have found a broad range of thoughtful and considered thinking on the issue in both the traditional and electronic media. I am confident that a full and frank debate about the FTTH NBN proposal will eventually result in a policy that will be in the interests of all Australians.

Some important throat clearing comments first up:

  • I believe that Australia needs better broadband access.
  • I agree that optical fibre is technically the superior technical solution to supplying fast high capacity broadband.

Some other important considerations:

The attempt in Australia to regulate a private monopoly of the fixed connection network was a dismal failure. It seems clear to me that the government must resume an important controlling role in the delivery of a fixed connection network to ensure that at least some regard is given to the public interest. Accordingly, it is important that the government buy back the farm (a.k.a the wholesale fixed connection network currently owned by Telstra).

Having bought back the farm, the government should immediately sell down its interest to 51%. The remaining 49% can be sold to private investors, ideally the retail suppliers who have, or should have, an interest in the provision of a high quality fixed connection network and thus actively contribute to ensuring that the fixed connection wholesale supplier is well run. One approach might be simply to leave a 49% interest with Telstra and let them sell down their share as they see fit.

The advantage of this approach is that the new wholesale fixed connection entity would immediately have a source of cashflow and the capacity to generate a commercial rate of return. Some of that cashflow could then be allocated to the improvement of the fixed connection network – more on that below. Additional investment could be raised by debt or capital investment by the shareholders. In short this entity would be making money from wholesaling access to the existing copper network.

The 51% government stake in the new wholesale organisation must remain in public hands as regulating private monopolies does not seem to be a strong point of our public administration.

While I am not entirely convinced that, given the choice, consumers over the next decade will continue to believe that a fixed connection for telephone/ internet is necessary, for reasons set out below I have assumed that every house will want and continue to require a fixed connection.

On the assumption that a fixed connection to every house remains desirable, it seems sensible that any new connections to new houses should be via an optical fibre. While I have no statistics to back me up, the cost of laying a new fibre connection as opposed to a new copper connection to a new house should be roughly similar. To the extent that optical fibre may be more expensive, the advantages of that technology would greatly exceed the difference in cost.

Households who currently have little or no access to a decent ADSL or HFC cable connection (the stuff used by Optus and Foxtel Pay TV) should be prioritised for improved connections. These connections could be initially fibre to the node (FTTN), to allow fast ADSL access, and eventually FTTH or if it is more cost effective to skip the interim FTTN step, FTTH immediately .

Fibre connections to public buildings or commercial premises should be given high priority as these users are much more likely to benefit from and be in a position to make practical use of the faster broad band connection that FTTH allows. Most of the applications for FTTH that I have read about seem most relevant to public or commercial buildings.

Households who currently have good quality ADSL or HFC connections would be given a much lower priority and may not be converted to FTTH for a long time or at least until demand clearly requires or the proposal outlined below is implemented. Assessing demand will be quite easy as, by that time, large numbers of new houses will have acccess to FTTH and word will have spread if it proves to be a compelling proposition for residential users. We will not need to speculate whether consumers will choose to improve their existing ADSL or HFC fixed connections to optical fibre.

Where sections of the existing copper network fail or prove to be more expensive to maintain than to replace they should be replaced with fibre.

Competition by private wireless networks should continue and be encouraged.

Will there be a continuing need for fixed connections to households?

Perhaps the greatest weakness of the current FTTH NBN proposal is the assumption by its proponents that a majority of households will wish to maintain a fixed connection (for telephone or internet) of any description to their home.

Increasingly many people, particularly young people, do not bother having a fixed phone connection at all. They have a mobile number and that is that.

This trend seems highly unlikely to reverse.

What does this mean for internet access via a fixed connection, arguably the only remaining persuasive reason for a fixed connection to many houses?

This year can be regarded as the year of the smart phone/smart appliance.

Although Apple iPhone had the field much to itself over the last few years, the rise of android, improvements to Nokia’s symbion and the impending arrival of Win 7 mobile seem likely to herald the storming of the mass market by smart phones.

Needless to say the market for iPads, tablets and e-readers will only further expand the demand for mobile internet access.

Although the limitations of wireless broadband are obvious to the old hands of fixed broadband (myself included) it is dangerous to assume that young people whose primary experience of the internet is framed by their smart phone gadget will see things the same way.

It may be that for most of their needs their smart phone will be perfectly fine and they will see no more need for a fixed broadband connection than they do for a fixed telephone connection.

Simply put – they may settlle for second best wireless connection because second best suits what they want from the internet.

They may wish for improved wireless broadband but it is not safe to assume that they will have a need for a fixed broadband connection simply because it is technically superior.

Mobility may trump speed and capacity.

At the present time, in the midst of explosive growth in consumer demand for mobile connections, the proponents of a FTTH NBN network are simply failing to articulate a persuasive case as to why the community should spend a large amount of money replacing the existing copper and HFC cable connections to the millions of households who currently have access to adequate broadband connections using those technologies.

To the extent that it is possible to gauge consumer interest in the FTTH NBN, it is clear that there will be insufficient consumer demand for its high speed fixed connections unless the consumer is denied the current fixed connection alternatives available to many of them – copper and HFC cable.

The most compelling argument in favour of a FTTH NBN

I have read much about the exciting ways the capacity and speed of FTTH broadband can be applied, but few of them are convincing as mainstream applications for residential users.

I appreciate that this may simply reflect the limits of my imagination and the imaginations of the current crop of futurists vibing the brave new world of FTTH, so I will keep an open mind that someone will come up with something in due course.

I believe there is only one application that makes a compelling case for a FTTH fixed connection network. Broadcast TV and video on demand including Pay TV and IP TV.

If radio tramission of all television was to cease when an area is fully supplied with FTTH and all free to air TV was supplied via the FTTH then many, if not all, households would demand a connection and a device that would allow them to feed the TV signal into their TV set.

Not only would this create a genuine need for FTTH but it would allow the considerable amount of valuable radio spectrum currently used by the analogue and digitial television broadcasts to be reused for other purposes including possibly 3G and 4G wireless.

There seems little justification for continuing to use valuable radio spectrum for the purpose of delivering SD and HD video programming which could be delivered simply and effectively by an optical fibre.

It is better that as much radio spectrum as possible is available for the provision of mobile internet access particularly as it is likely that mobile internet access will be favoured by many if not most consumers.

The auction of that spectrum to telcos and other wireless internet providers would go someway to defray the cost of the FTTH roll out, particularly those sections of the FTTH network where a universal service obligation may be the only reason for construction.

The availability and universal coverage of the FTTH would also allow multiple existing and new pay TV providers to use the cable as their main method of service delivery – especially to areas not currently supplied by existing technologies.

Summary

In short the proposal is as follows:

  • Have the government buy back a 51% interest in the wholesale fixed network – buy back the copper (this new wholesale fixed connection supplier would generate an immediate return from the existing copper fixed telephone and ADSL connections)
  • Fixed connections to new housing to be optical fibre
  • Existing houses with no access to HFC networks or ADSL to be provided with FTTN (or possibly FTTH)
  • Prioritise optical fibre connections to public buildings and commercial premises
  • No change to FTTH for existing houses with HFC or decent ADSL until it is clear that there is consumer demand to do so
  • All existing free to air TV to be supplied via the optical fibre to build community acceptance for non-broadcast supply of TV
  • As engineering and technical resources (including labour) allow progressively convert TV broadcast regions to FTTH and when connections are complete and operating turn off the broadcast TV signal
  • Auction the broadcast TV digital and analogue spectrum for alternate uses – say 3G and 4G wireless

The irony inherent in the proposal set out above is that while the FTTH connection could be used for ‘internet access’ as we currently understand it, the primary objective of the FTTH would be to facilitate the provision of increasing amounts of wireless internet access to mobile devices by removing TV (analogue and digital) from the radio spectrum.

Furthermore, it also suggests that the proponents of a FTTH NBN might be better served by promoting the capacity of the FTTH to deliver TV, pay TV and other forms of video entertainment that the consumers value highly as this would allow improved wireless connections to deliver the lion’s share of the internet access that most consumers are likely to want in the future.

For remote houses that cannot be connected with FTTH – satellite delivery of free to air TV and Pay TV should be available.

How old is the Mule?

According to one automated blog analyser, I am rather older than I thought I was:

stubbornmule.net is probably written by a male somewhere between 66-100 years old. The writing style is academic and upset most of the time

The gender is correct and academic writing style I can accept, but I am not so sure about being upset most of the time. Generally I am quite happy while writing the blog!

Getting Protovis working on WordPress

When I started experimenting with Protovis*, I quickly found that getting it to work in a WordPress blog was rather fiddly. With a lot of help from Google (and this page in particular), I managed to piece together what needed to be done, but since I did not find any explanations specifically focused on Protovis in WordPress, I thought it may be useful for others attempting the same thing if I summarised the steps involved. Most readers will not have the slightest interest in this, so I will not expect many of you to keep reading!

First of all, if you are hosting your blog on WordPress.com, give up now! These instructions will only work if you have a self-hosted installation of WordPress.

1. Download Protovis and unzip it on your server it a convenient location. I put it in a folder called “protovis”, accessible from the root of the webserver.

2. Ensure your headers include a pointer to the Protovis script. How exactly you do this, depends on your theme, but since I am using Thesis, it’s quite straightforward: under Site Options > Additional Scripts, I added the following code.

<link rel="shortcut icon" type="image/x-icon" href="/favicon.ico">
 <script type="text/javascript" src="/protovis/protovis-r3.2.js"></script>

3. Wrap your Protovis code up in a function and save it in a .js file on the server. For example, here is the code I used to produce the chart in the last post. You will see that I wrapped everything up in a function called “cdodraw”. I saved the file in the folder /script/pv.

4. Edit your post in HTML mode and use the following code to load and call your function.

<script src="/scripts/pv/cdodraw.js" type="text/javascript"></script>
<script type="text/javascript+protovis"><!--
cdodraw();
--></script>

You should replace “/scripts/pv/cdodraw.js” with the location of your own Protovis chart code and replace “cdodraw()”. With the name of your own function. Note that the first script command has type “text/javascript” and the second “text/javascript+protovis”. This is important!

Part of the reason for the difficulty is that WordPress has a tendency to mash up the text you enter, which is fine most of the time, but not when you are trying to write Javascript. An alternative may be to try the Text Control plugin, which allows finer control over WordPress’s mashing of your text. I have not tried the plugin myself, so I cannot be sure how well it works.

Good luck, and let me know how you go! If you have any suggestions on how to do this a better way, please let me know. Better still, you could write a WordPress plugin to make it all much easier.

UPDATE: it appears that this function-wrapping trick does not work for Google Chrome or Safari. I’m looking into it!

FURTHER UPDATE: I could not work out why the approach described here does not work for Chrome or Safari, so instead I got it working by creating a custom shortcode that slurps in a javascript file and includes it in the post. I am in the process of wrapping this up in a plugin to save others the trouble of working out how to do it. For those who cannot wait, here is the code I used:

function sProtovis($atts, $content = null) {
 extract(shortcode_atts(array('src' => '#'), $atts));
 return '<script type="text/javascript+protovis">'."\n".file_get_contents($src).'</script><noscript>Scripts disabled -- cannot display chart!</noscript>'.'<p align="center"><strong>'.do_shortcode($content).'</strong></p>';
}
add_shortcode('protovis', 'sProtovis');

It still relies on the Protovis code already being added into the header (as described above). In the plugin, this will no longer be necessary.

PLUGIN: pv-loader is now available on github.

* Protovis is a javascript data visualisation library being developed at Stanford, which allows the creation of interactive charts on web pages.

Experimenting with Protovis

A couple of weeks ago I gave a talk on using graphics in R. During the question session, someone asked whether I had tried using Protovis, a javascript data visualisation library being developed at Stanford. It was an easy question to answer: no!

However, a bit of subsequent investigation revealed that Protovis has been developed very much in the spirit of Leland Wilkinson’s book The Grammar of Graphics, which I am currently reading, so I have decided to experiment with it here on the blog.

The charts I generate with R are all static images, while a tool like Protovis allows for user interaction which opens up some interesting possibilities. Compared to R, which I have been using for around 10 years, Protovis presents a double challenge: not only do I have to come to grips with Protovis itself, but I will also have to learn some basic Javascript programming. So, I expect it to be a slow journey.

As a tentative first step, I have reproduced the CDO chart from a recent post ranting about bubble charts. At first glance, it is essentially identical to the chart I produced using R. However, if you hover your mouse over the points on the chart, you should see the figures appear! It is by no means perfect (for example, it would probably look better if single points appeared, rather than every point on the chart and it could do with a legend), but it’s a start and I will persevere.

[pvis src=”http://stubbornmule.net/scripts/pv/test.js” img=”http://stubbornmule.net/blog/wp-content/CDO-circles.png” height=”125px”]CDO deals: total and recycled[/pvis]

Producing scripts using a Javascript library does have its drawbacks. For a start, it means the chart will only be visible when scripts can be run, so if you are reading this in an email or an RSS news reader, you will probably not see very much and will have to visit the page on the blog to see it. Even then, some of you may use script-blockers such as NoScript which will also break the chart (mind you, you can trust the Mule, so you could always whitelist this site!). Finally, I believe that some older browsers (such as IE6) will not support Protovis. It would be useful to see how many people can or cannot see the chart, so please let me know using this poll whether you can see the chart.


(polls)

Getting Protovis to work on the blog was a little fiddly, so for anyone interested, I have also written up a quick guide to using Protovis on a WordPress blog.

UPDATE: Reports in so far indicate that the chart is not working in Google Chrome or on mobile devices. More work to do it would seem!

The Mule goes SURFing

A month ago I posted about “SURF”, the newly-established Sydney R user forum (R being an excellent open-source statistics tool). Shortly after publishing that post, I attended the inaugural forum meeting.

While we waited for attendees to arrive, a few people introduced themselves, explaining why they were interested in R and how much experience they had with the system. I was surprised at the diversity of backgrounds represented: there was someone from the department of immigration, a few from various areas within the health-care industry, a group from the Australian Copyright Council (I think I’ve got that right—it was certainly something to do with copyright), a few from finance, some academics and even someone from the office of state revenue.

Of the 30 or so people who came to the meeting, many classed themselves as beginners when it came to R (although most had experience with other systems, such as SAS). So if there’s anyone out there who was toying with the idea of signing up but hesitated out of concern that they know nothing about R, do not fear. You will not be alone.

The forum organizer, Eugene Dubossarsky, proceeded to give an overview of the recent growth in R’s popularity and also gave a live demo of how quickly and easily you can get R installed and running. Since there were so many beginners, Eugene suggested that a few of the more experienced users could act as mentors to those interested in learning more about R. As someone who has used R for over 10 years, I volunteered my services. So feel free to ask me any and all of your R questions!

As well as being a volunteer mentor, I will have the pleasure of being the presenter at the next forum meeting on the 18th of August. Regular readers of the Stubborn Mule will not be surprised to learn that the topic I have chosen is The Power of Graphics in R. Here’s the overview of what I will be talking about:

In addition to its statistical computing prowess, R is one of the most sophisticated and flexible tools around for visualizing quantitative data. It can produce a wide variety of chart types, including scatter plots, box plots, dot plots, mosaic plots, 3D charts and more. Tweaking chart settings and adding customized annotations is a breeze and the charts can readily be output to a range of formats including images (jpeg or png), PDF and metafile formats.

Topics covered in this talk include:

  • Getting started with graphing in R
  • The basic charting types available
  • Customising charts (labels, axes, colour, annotations and more)
  • Managing different output formats
  • A look at the more advanced charting packages: lattice and ggplot2

Anyone who ever has a need to visualize their data, whether simply for exploration or for producing slick graphics for reports and presentations can benefit from learning to use R’s graphics features. The material presented here will get you well on your way. If you have ever been frustrated when trying to get charts in Excel to behave themselves, you will never look back once you switch to R.

For those of you in Sydney who are interested in a glimpse of how I use R to produce the charts you see here on the blog, feel free to come along. I hope to see you there!

Graphing using R

R Project logoLong-time readers of the Stubborn Mule will know that charts are a regular feature here. Almost all of these charts were produced using the R statistical software package which, in my view, produces far superior results to the most commonly used graphing tool: Excel. As a community service to help rid the world of horrible Excel charts, here is a quick tutorial on charting using R. Since R is a powerful and versatile tool, there is a lot more to it than covered here, so there may be more tutorials to come.

Installing and Running R

The first step is to get R installed on your computer. R is open source and can be downloaded for free from the Comprehensive R Archive Network (CRAN). It comes in many flavours: Mac, Windows and Linux.

Once you have installed R and have fired it up, you are presented with something that looks very different to Excel. This is the first indication that R is an interactive programming environment not a spreadsheet. You will see various messages, including copyright information, some instructions on how to display licence information, how to run a demo, get help, and finally you are presented with a command prompt: “>”. R is now waiting for you to type commands.

As an example, try entering the following command:

getwd()

This will display the current “working directory” (hence “wd”), which is the default folder that R will use for reading and writing data. You can easily change the working directory, either by using the drop-down menus (which menu option varies depending on whether you are using Windows, Mac or Linux) or by using the setwd command:

setwd("/Documents/Mule Docs")

Unless you have a “Mule Docs” folder in a “Documents” folder, you will need to substitute the name of one of your own folders, otherwise you will get an error message. Note that you need to use forward slashes (“/”) rather than backslashes (“\”) even on Windows.

You can see detailed explanations of any R command by prefixing the name of the command with a question mark:

?setwd

This is short for help(setwd). Of course, this assumes you know the name of the command already. To search the documentation for a keyword, use a double question-mark. For example

??median

will show a list of all the commands which feature the word “median” in their documentation. This is short for help.search(“median”). Note the use of double quotes (“) here, not required in the ?? syntax.

Reading Data and Charting

To get started, here is a simple data file in CSV fomat (“comma separated values”). Download it and save it in your working directory (or save it somewhere else and then change R’s working directory to where you just saved the file). You can then load the data into R with the following command:

x <- read.csv("demo.csv")

While the read.csv part is self-explanatory, the “<-” may look a little odd. It is the assignment operator. Whereas most programming languages simply use an “=” to assign to variables, R uses what is intended to look like an arrow. In this case, you should interpret the command as saying “read the contents of the file demo.csv and place the result in the variable x“.  To see the contents of x, you can simply type x at the command line and press return, which will display a table with all the data read from the demo.csv file. When dealing with larger “data frames” (to use the R lingo for this type of object), having that much data flash by may not be very useful. Some other useful commands for quickly inspecting your data are:

head(x)
tail(x)
summary(x)

Now you are ready for your first graph. Try this command:

plot(x)

You should see a simple, clean scatter-plot. If you would prefer a line graph, this is easily done too.

plot(x, type="l")

The plot function has many options, which you can explore in the documentation (just enter ?plot). There are also various commands for further annotations for your chart. Try the following commands:

grid()
axis(side=4)
text(2, -4, "Random Walk")

These will add gridlines, put axis labels on the right-hand sides (R numbers chart sides from 1 to 4 starting from the bottom and working clockwise) and finally displays text on the chart.

Using Program Files

Using R interactively like this is useful for familiarising yourself with the system and for performing quick calculations, but if you find yourself wanting to make small changes here and there, it will quickly become annoying re-typing long commands. This is when you should move to using program files. All that this involves is saving a series of R commands to a file using a text editor (you can just use a simple text editor like Notepad or TextEdit, but many fancier applications can help out by automatically highlighting R commands in different colours, a trick known as “syntax highlighting”). Here is one I prepared earlier: demo.R (by convention, R files are given the .R extension). You can download this and save it into the same folder as the demo.csv file. To execute a program file once you have saved it, you use the source command:

source("demo.R")

This example will also produce a chart of the demo data, but this time it saves the result to an image file (using the Portable Network Graphics image format). This is done using the png command:

png("demo.png", width=400, height=400)

The main parameters for this command are the filename of the image you want to produce and the size of the image. After you execute all of your desired charting commands, you must close off the graphics “device” and save the results, which is done using the following command:

dev.off()

To find out more about graphics “devices” in R, including saving to other file formats (such as PDF or JPEG), have a look at ?Devices.

So that’s it. You are up and running producing charts with R. To go further from here, while you wait for further tutorials, you can explore some of the R files I have used to produce charts for the blog. I store quite a few of them here on github.

The Re-birth of the Tablet

Last year I bought a Kindle e-book reader and wrote about its strengths and weaknesses. With the release of Apple’s iPad last month, people keep asking me whether I wish I had waited for that instead. The short answer is, no, but now a fellow gadget-aficionado, Tony (aka @thewordpressguy) has drawn my attention to another new device, the TEGA tablet, and has asked me for an opinion*. I am yet to get my hands on either device, but I won’t let that stop me expressing a view!

The history of tablet computers is showing every sign of repeating the pattern of mp3 players. The first mp3 player pre-dated the iPod by about 5 years, but it was not until Apple entered the market that they really began to take off. Two key factors behind Apple’s success were design and the iTunes store. Having owned a Creative Nomad Jukebox and an iRiver H340 before getting an iPod, I experienced first-hand how much better the user-interface of the iPod was than everything that came before (even if it lagged at times in its technical specifications). The iTunes store was even more important. While early-adopting enthusiasts like me may have had the motivation and patience to convert all of my CDs to mp3 format, this would not be true of most people. The iTunes store provided a simple and reasonably-priced way for people to get content onto their iPods. The rest is history.

Just like iPods, tablets have been around for some time before Apple entered the fray. The term was popularised by Microsoft in 2001, but tablets were around in one form or another well before that (you could even include Apple’s less than successful Newton). Just like the iPod, the iPad is no doubt a superbly-designed piece of hardware, with an intelligent user-interface (I am extrapolating from my experience with the iPhone as well as taking into account the plethora of articles I have read about the iPad). Combine that with the App store, which is to the iPad and iPhone what the iTunes store was to the iPod, and the success of the iPad looks assured.

While the iPod came to dominate the mp3 player market, the iPad may stimulate the emergence of a broader range of alternative tablets, much as the Google Android phone is showing signs of being a serious alternative to the iPhone. Based on Tony’s assessment of the TEGA, it could well be an early example of this phenomenon. While it does not offer Apple design, it does have a few other things instead, such as USB, card-reader ports (rather than having to rely on external adapters as the iPad does) and a built in 3G modem which allows you to pop in your own sim card (so no more 3G dongles). What may hold even greater appeal for some is that it is operating-system agnostic: while most people would buy it with Windows 7 installed, it will also ship with Linux.

The release of the TEGA is an interesting development and I am sure there will be more iPad alternatives to come, but that brings me back to the original question. Do I have Kindle-regret? Would an iPad, a TEGA or something else be better?

I do not. The Kindle certainly has its shortcomings, some of which I discussed in my original review, but here’s what it gives me that the alternatives do not:

  • electronic-ink display – while the page-turning flicker may be annoying to some, I continue to find it a very easy medium to read, particularly in bright light
  • battery life – with 3G turned off (except for when I am making a purchase), I get two weeks or more between charges. The iPad offers an impressive 10 hours, so the gap is closing, but the Kindle retains the lead for now. Clocking in at only 2.5 hours, the TEGA remains a laggard on this score and it cannot be a serious contender until this improves.
  • price –  compared to prices of portable computers only a few years ago, with prices starting at US$499 the iPad looks cheap. But at US$259, the Kindle is a lot cheaper. Of course, it cannot do what the iPad can do, but if you are after an e-book reader (as I was) that may not matter. The TEGA is closer to US$1,000 (A$1,187.98) and at that price looks expensive.
  • continuous partial attention – on a computer I cannot help flicking from email to twitter to following links, so perhaps I suffer from a touch of CPA. What this means is that a single-purpose device like the Kindle is ideal for me and offers a better, less-interrupted reading experience. It may seem absurd to some to want to impose restrictions on a device, but in this case it is an advantage for me.

As a bit of a gadget-obsessive, I may well succumb to the lure of an iPad one day (perhaps 2.0), or indeed a descendant of the TEGA or something similar. For now though, I will happily continue reading on the Kindle.

* In the interest of full disclosure, I should point out that if enough fellow-bloggers post on the topic of the TEGA, Tony will have the option of purchasing a heavily-discounted unit.

Gigabang for your buck

This week Fairfax reported on Australia’s broadband pricing “war” in an article appearing in both the Sydney Morning Herald and the Age. The publisher thoughtfully spared online readers the egregious chart that it foisted on readers of the paper editions. Judging from this junk (to use the official adjective for low-quality charts), these newspapers should stick to journalism and steer clear of graphics.

The chart in question was brought to my attention by Mule Stable regular @zebra, who also kindly scanned it (and devised the headline of this post), allowing me to reproduce it here. It shows the pricing of a number of broadband internet plans offered by the four largest internet service providers (ISPs) in Australia.

Terribly designed chart showing prices vs download limits

Chart from print edition of The Age (29 April 2010)

It is a busy chart, made difficult to read by a number of ill-advised design decisions:

  • the horizontal axis reads from right to left rather than the conventional left to right
  • although labeled “Price vs Download”, price is on the horizontal axis, again violating convention*
  • repeating the ISP label for every point adds unnecessarily to the busy-ness of the chart and it also makes the legend redundant
  • labeling each point with the download limit (although not the price), adds more unnecessary ink

These conventions are arbitrary: we could just as well have developed a tradition in the West of reading from right to left, for example. But once a convention is in place, you have to have a very good reason to break with it. Otherwise, you end up making your chart harder for readers to interpret for no good reason.

But perhaps the biggest weakness in the chart is the labeling of the ISPs. Each has its own colour, but this is not enough for the eye to naturally group them together, which makes it hard to track the pricing trend provider by provider. This is easily addressed by connecting the points for each ISP with lines. Once this is done and the other short-comings are also addressed, a couple of anomalies in the data leap out immediately. Compared to their other plans, the Optus 100GB plan and the TPG 150GB appear dramatically over-priced, costing more than other plans that offer more data.

Improved chart of ISP plans $ v GBImproved version: Price vs Download limit

Of course, this phenomenon was there in the original chart, but it was hidden. So much so, that the journalist does not appear to have noticed at all as it went unremarked in the article. This is a good example of the power of good charting technique.

There are a number of possible explanations for the anomalous data points. They could simply be errors, although it is certainly not impossible (or perhaps even unlikely) that ISPs have illogical pricing policies. A more likely explanation is that the data includes apples and oranges: the higher-priced plans may be bundles offering additional services such as VOIP that are not included in the other more basic plans. Perhaps if Fairfax had done a better job on the chart in the first place, the journalist may have been prompted to answer this question for us.

* Typically “dependent variables” (the y of “y versus x”) appear on the vertical axis and “independent variables” on the horizontal axis.