Archive for the 'Computers' Category

Wolfram Alpha – the good, the bad, the ugly

May 17th, 2009

The most interesting search engine to be launched in years just went public: Wolfram Alpha

Wolfram Alpha sells itself as a ‘computational knowledge engine’. And it’s a very nice proof of concept. But as it stands there’s some things about it that are quite poorly developed, and some things that should be removed immediately.

Search of US GDP to get an idea of what it can do. You get a nice output of the value per year, automatically converted into $A in my case.

But some of the data here is badly out of date. For instance:

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GDP per capita 16th in the world? There are a few countries ahead of the US, but it shouldn’t be that many. Wikipedia (which looks right, but I haven’t double checked) says that the US should be more like 4th to 6th. It looks like it’s a combination of counting things as countries that economists don’t normally include, but also a product of outdated data.

Let’s try another example – seach for my name. A bit US centric, but that’s only to be expected I suppose. But here’s the neatest bit: if someone’s name is Robert, how old are they likely to be:

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The system has pretty sharp limits. For instance, at the moment I’m interested in Australia’s GDP growth. The basic search works fine, but the most recent growth rate they have is 2005. Which makes that search completely useless – what’s important is now, not 4 years ago. And even the US only has growth rates from 2005. That’s bad, bordering on dangerous for people who don’t check the fine print.

But finally, moving on to the ugly. If you search for a stock you get a lot of data. Try Google as a search on Wolfram Alpha. Mostly a nice summary of market data on the company, fine. But down towards the bottom of the page you get this:

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There is no way to describe this but dangerous and irresponsible. This projection will change every time you open the page, so don’t expect to see the results each time. The engine takes a well understood random walk approach, and produces projections using no information other than the historical variations in the stock.

But that’s a very silly thing to do. Sure, over history stocks and other real values seem to follow something that looks like a random walk. But that doesn’t mean that any individual random walk is of value. Or even a set of 5. This forecast has as much value as me asking my cat to walk across a sheet of paper with muddy paws, and then using the positions of the marks to project the stock. Soothsayers looking at entrails have more credibility than this, because they’re at least using their own judgement and intuition subconsciously.

Any informed observer won’t get hurt by this, but what about someone who isn’t that literate in this sort of analysis? What if the random odds give five paths that all point well up? And what if they then go and put their life savings in the stock as well.

If this sort of analysis is going to be included on the Wolfram Alpha search engine then it needs to be accompanied by far more prominent warnings about the use of this sort of analysis, as opposed to their current totally inadequate disclaimer.


How to build a small media centre PC for standard definition TV for less than $A 500

May 5th, 2009

I decided that I needed a new TV to put in my bedroom. Also, it’s been a year since I played with building a computer, so I decided to try my hand at building an Intel Atom based PC.

Parts

A quick glance over AusPCMarket, and a quick email to Dan of Dansdata led me to get the following parts (all prices in Australian dollars):

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After that I just needed one more parts, which I got from JB Hi-Fi:

  • ASUS 13″ Widescreen monitor, $98.00

Total cost was $445.02.

Building

Step 1: Open the case up.

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The Aywun case is quite small, and just needs two thumb screws removed to take it out. There’s a frame to attach the slimline CD drive and a hard drive, but I won’t be needing those for this configuration.

Step 2: Insert the port template into the case.

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Step 3: Attach the motherboard to the case.

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It’s a small case, this was a bit of a tight fit and needed a little bit of juggling around to fit everything in.

Step 4: Insert the memory into the motherboard.

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As always with memory, I put it in the wrong way around the first time I tried. Fortunately it’s pretty hard to get DDR2 RAM wrong. Just push gently and the RAM locks in place.

Step 5: Attach the front panel cables to the motherboard.

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These fiddly cables were a lot easier than the last PC I built – this is normally the bit I end up cursing, but this time it only took a minute.

Step 6: Attach the power cable to the motherboard.

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Step 7: Close the case up.

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I’m leaving the drive frame out, so keeping the cables neat is pretty easy. With a CD drive and a hard drive power and heat management would start to be a problem.

Step 8: Attach monitor.

Step 9: Boot and check configuration.

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As it turns out, the BIOS for this motherboard is well set up to use with a USB stick rather than a hard drive – it was probably easier to set up than if I needed to boot from HDD…

Software

To run this computer I chose XBox Media Centre, mainly because I’ve used it before and been happy with it, but also because it comes with a live CD.

Step 1: XBMC Live image.

The version of XBMC to use is the live version, which includes a cutdown version of Ubuntu.

Step 2: Install to USB stick.

The slightly tricky bit is that, by default, you can’t simply copy the XBMC live onto a USB stick, as it needs a Linux file system. So to run the thing most easily, I downloaded VirtualBox.

I then just set up a simple virtual machine with no devices attached other than the USB stick and the ISO image in the CD drive.

After that, these instructions got me the rest of the way. The only tricky bit was it didn’t recognise the USB stick initially, so I had to remove it from the computer and put it back in again, after which it worked fine.

Step 3: Boot computer from USB.

To make sure that there weren’t any problems with the software, first I booted my main PC from the USB. Once that was confirmed to work, I moved on to the new box.

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Everything worked first time with little problems.

Next Steps

So now I have a small PC that boots and runs XBMC.

Still a couple of things to get working before it’s ready to go:

  • The remote control needs to be configured. At the moment the buttons aren’t working properly. It turns out that rather than showing up as an IR receiver, it’s showing up as a keyboard. I just need to find some way to map the keys properly.

  • A slightly bigger issue is networking. The USB wireless stick I have isn’t working out of the box at the moment, so either I need to get it working, or go to the backup plan (using an old router I have set up in bridge mode).

  • I haven’t tested the sound yet – it’d be surprising if it was a problem, though.


Hands up if you can see the problem

February 27th, 2008

Net Neutrality is one of the biggest hot button issues among the nerd illuminati of the Internet right now. The simple question is whether all internet bits are equal, or should ISPs be allowed to privilege some bits (from their customers or people who pay them) over others.

There are some side issues here, but a big part of it is peer to peer. Which brings me to this story from today that online video distributors can save a lot of money by using peer to peer protocols

In the example given, Democracy Now saves $1,000 (of a $1,200 bill) by using BitTorrent. My question is – who ends up paying that $1,000? If we assume (and it’s not a great assumption) that everything is competitive, then that $1,200 represents the cost of pushing that many bits to end users. If it goes down, then it must mean that $1,000 worth of bits are now being pushed by someone else – in this case, the upstream bandwidth from the users.

So who pays?

At first, probably the ISP of the end users. Their bandwidth out gets used up, costing them money.

They’ll pretty quickly pass that on to the end users. Which means they’ll increase prices for everyone.

So what’s DemocracyNow really doing here? They’re pushing the costs of distributing from themselves on to end users. Which, due to the way pricing is set up, will be borne equally by everyone, regardless of how interested they are. In fact, people who have no interest at all in the video probably end up paying for this too.

I’m not arguing against net neutrality – there are other reasons why it’s a good idea. This is probably more an example of how the pricing for internet access is set up wrong – flat rate charges create strange incentives across the Internet, not just for the end users.

But that $1,000 saving? That doesn’t exist. You’re just making other people pay it.


Yay ADSL2!

December 4th, 2006

Just got an email from my ISP (the fabulous Internode) to tell me that my upgrade to ADSL2 will be happening sometime next week. Should pretty much quadruple my internet connection speed, which will be very nice indeed.


Google spreadsheets is not an Excel killer

June 8th, 2006

It seems that lots of people are all aflutter over Google Spreadsheets.

I personally doubt that it’s going to have any impact whatsoever on Excel and Office more generally.

Firstly, most people who use Excel use it fairly peripherally. Word is by far the most used of the programs in the Office suite. Most uses of Excel are going to be pretty peripheral. When these people use Excel they mainly use the ‘simple’ functions: sum, average, and so on. Will they use the Google Spreadsheets? Maybe, but I’d guess that as a lot of this is for personal financial information (budgets and the like) they may well be a bit reluctant to put it out on the web.

So who uses Excel the most? To guess (without any data) I’d say that the biggest users would be people who work with company financial data, followed by scientists and social scientists who work with quantitative data. Firstly, a lot of this information is confidential, either commerically or otherwise. They simply won’t be allowed to use something like Google Spreadsheets. Some might ignore that restriction, but most won’t. But more importantly, they use a lot of the higher end functions. Things like pivot tables, lookup functions, the statistical programs and so on (update: well, the lookup functions at least are included). While we’re still waiting to see the full feature set for the Google version, I’ll be very surprised if everything I need for spreadsheets is included.

A couple of other important question marks include spreadsheet linking. Can you link a cell in one file to another cell in a seperate file? This is a very common use for advanced Excel users, and without it Google Spreadsheets will be useless.

One final reason why most advanced users will stay away is other programs. Most data analysis programs (STATA, SAS, etc.) can read excel files. But they won’t read these Google files. While you can download them as .xls to your local drive, while add another step when you already have Excel installed?

So I don’t think anyone at Redmond is very worried today.

Now a Google Wordprocessor could be a whole other story, as there’s a lot more casual use of that program.


Ever buying any computer hardware?

May 4th, 2006

staticICE seems to be a useful search engine for Australian computer hardware prices.

(Nothing very new, but most of the ones on the ‘net are US-centric).