Archive for October, 2008

October 7th, 2008

So..I finally get hold of a standalone copy of MATLAB 2008a and set about installing it on my Ubuntu laptop. I have installed MATLAB literally hundreds (if not thousands) of times so this is going to be easy. Right? Wrong!

I am using the installation DVD which is mounted at /media/cdrom0 so I type the following into the bash command prompt:

/media/cdrom0/install

bash: /media/cdrom0/install: /bin/sh: bad interpreter: Permission denied

gah! OK, no problem – I’ve seen this before so I type

sh /media/cdrom0/install

-------------------------------------------------------------------

    An error status was returned by the program 'xsetup',
    the X Window System version of 'install'. The following
    messages were written to standard error:

        /media/cdrom0/update/install/main.sh: 178:
                 /media/cdrom0/update/bin/glnx86/xsetup: Permission denied

    Attempt to fix the problem and try again. If X is not available
    or 'xsetup' cannot be made to work then try the terminal
    version of 'install' using the command:

            install* -t    or    INSTALL* -t

-------------------------------------------------------------------

    Sorry! Setup aborted . . .

Permission denied? Ahh, I should have used sudo – silly me. After all, if I don’t then I am going to run into trouble eventually. So I try

sudo sh /media/cdrom0/install

Same result as before it seems. Let’s try the suggestion given by the install script and run the text only installer:

sudo sh /media/cdrom0/install* -t

I get asked if I want to agree to the license agreement before getting this error:

/media/cdrom0/update/install/main.sh: 582: /media/cdrom0/update/bin/glnx86/xsetup: Permission denied

Before I rolled my sleeves up and got my hands really dirty I did some googling. This link offers some advice – unmount and remount the DVD as follows:

sudo umount /media/cdrom0
sudo mount -o exec,suid /dev/scd0 /media/cdrom0

then run the installer again:

sudo sh /media/cdrom0/install

Success! Hope it worked for you too :)

October 7th, 2008

I have been using the current theme on Walking Randomly ever since I started and, for the most part, I really like it but just recently I have started to get fed up with it for various reasons and so I am thinking of a change. Essentially I need a drop-in replacement since my HTML / CSS coding skills are basic and non-existent respectively. Does anyone have any advice?

October 7th, 2008

I now have access to a standalone copy of MATLAB along with a whole slew of toolboxes. This means that I can play with MATLAB on my many many train journeys so expect to see a lot more MATLAB-centric content here soon :)

October 6th, 2008

SpaceTime 3.0 has been ported over to the iPhone and will be available soon according to the product’s web page. Since I don’t have an iPhone, it is highly unlikely that I will ever get to try this port but I have used SpaceTime on my Windows Mobile phone and, in my opinion at least, it is probably the best computer algebra system available for mobile devices. The next best thing to having Mathematica on your mobile phone!

One thing that immediately jumped out at me is the price increase for the iPhone version. It costs $19.99 for the Windows Mobile version but (at the time of writing) it seems that the iPhone version is going to sell for $29.99. I wonder if there is any extra functionality for the additional 10 bucks?

October 3rd, 2008

While reading 360’s recent post about crop circles, I was reminded of something similar that caught my attention a while back – this:

What you are looking at is the phrase “Hello, world!” encoded in Semacode and mown into a wheat field. Measuring 160m x 160m, it is possibly the largest “Hello, World!” program every written. It was made back in 2007 by German programmer bernhard hopfengärtner who aimed (and succeeded) to get it included in aerial photography taken by Google Earth.

The Challenge

Now I have no idea if this is possible but that does not stop me asking the question. Can anyone come up with a program that takes the above image as input, parse the semacode and see if it really does print “Hello World.”

I guess something like MATLAB would have some of the required functionality in its image toolbox but I haven’t yet googled to see if there is a suitable open source Semacode algorithm that you could feed the image into.

Have fun!

October 3rd, 2008

Just as I was about to give up on the Carnival of Mathematics, up pops the long awaited 40th Edition over at Staring at Empty Pages. Lots of juicy mathematical tidbits have been included for your enjoyment including some interesting stuff on the factorial function, generating functions, Euclid’s Elements and a whole lot more.

I am a huge fan of the carnival of Maths and have hosted it twice myself so far. In my opinion, it’s a great way of discovering new maths-related blogs and new mathematical ideas. The carnival also helps foster a sense of community among us all. One thing that it desperately needs though is new hosts so please contact Alon and volunteer for the job.

The 41st carnival will be hosted by the guys over at 360. Do your blog a favour and submit your latest maths-related post to the carnival.

October 2nd, 2008

I’m in a good mood today – lots of things have gone right for me over the last few hours and the sun is shining (a rare event in Manchester – especially in October). Since I’m in such a good mood I thought that I would take a request or two.

As the title says – what tutorials would you like to see made available here? Technologies I could cover include Mathematica, MATLAB, NAG, Python, SAGE and several others. Subjects could include particular areas of Mathematics, programming or just something along the lines of ‘How do I make application XYZ do ABC’? If I don’t have enough smarts to do it myself then I will try to press gang someone into doing it for us.

I can’t make any promises of course but if you don’t ask you don’t get. So…while the sun is shining…ask away :)

October 2nd, 2008

I’ve linked to Blinkdagger a few times before because they write great introductory tutorials on how to use MATLAB in various fields. Their latest one, written by Rob Slazas, takes a look at how you can use some of the functions in the MATLAB statistics toolbox to test a hypothesis.

I freely admit to knowing nothing about this subject so couldn’t possibly comment on the technical accuracy of the post (although I would imagine that it’s just fine) but it certainly looks like a nice place to start. Head on over to blinkdagger to take a look.