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New Zealand Blog

November 21, 2012

Off to NZ today. Watch this space…..

Mawsons Air Tractor

September 27, 2012


In 1911 Sir Douglas Mawson led an expedition to Cape Denison, Antarctica, to claim territory for Britain, explore inland, find the magnetic south pole, and do considerable scientific research. He took a Vickers aeroplane, whose wings had been damaged and were removed, as an Air Tractor to pull sledges on the ice. It had a short life, the engine seizing on the third trip.

This movie, taken from existing clips on the web and re-mastered, shows the fuselage being unloaded, repairs over winter, and a demonstration run down the hill at the back of the hut. Note the two men on the back of the skis winding spikes into the ice – the only way they could steer.


Figuring Out Drupal Date Posts with Wolfram Alpha + Retrieving an Old Drupal MySQL database

September 28, 2011

Go to Wolfram Alpha:

The formula is simple:

“what date is 12.00am January 1st 1970 + 1201470000 seconds?” (minus the quotes)

The 1201470000 is the drupal timestamp in seconds, dated from 12.00am Jan 1st 1970

The reason I am posting this is as follows:

I had kept a blog using Drupal during 2004-7. I hadn’t really troubled myself about how I might possibly migrate from Drupal 4.n to another CMS later, though I kept upgrading Drupal and Mysql, PHP etc. till Drupal 5.n, when I migrated to WordPress – years later (in 2010) after a hiatus of several years. I had given up blogging using Drupal since about v.6.n. as it was overkill for what I was doing and WordPress seemed very attractive and simple (and lots of useful-for-me plug-ins, regularly updated)

The motivation has been to consolidate several different (historical) blogs kept on different servers using different CMSs into one contiguous blog. To bring it all together.

So, anyway, one day 3 or 4 years ago (I forget when), I decided I didn’t need my old Drupal site anymore – I had a mysql dump of the database as a tar.gz file – no problems!

A disaster – what the hell are you meant to do with this?

After years of doing nothing with it and all the category/xml referencing types have changed?

I tried importing it into Drupal 6.n running locally under MAMP (Mac OSX), but the result was a mad woman’s breakfast – that I simply had no idea what to do with.

So, now, about 6 years later, I am running a wordpress blog using MAMP – how to get that old stuff into the new system?

Well, after a bit of faffing around, I figured out that via the MAMP PHPMyAdmin interface that I could simply create a new database (figure it out yourself – I’m just providing hints here for the geeky few who might run across this problem) and import the old nodes.txt file from Drupal 5.n. There are a million other files  – but this one contains my text and links to my old photos/video etc (they may be contained as BLOBS (Binary Large Objects) in your backup cache file (I gave that a miss, after editing php.ini (via Smultron) for MAMP to upload over 32MB data to 264MB – a number big enough to import the largest mysql dump file – but there is no point for me to figure out what to do with it.))

It’s easy to look at these files using TextEdit or some other text editor.

Anyway, if you do any of this, naturally you should quit MAMP and restart the MAMP server to check any changes have effected.

After that, I exported my nodes.txt file as a nodes.xml file and opened it in Safari. (It reports it’s missing the XML references, but that’s of no import)

I suspect I could’ve just used the nodes.txt file anyway, but haven’t bothered to check.

This gave me access to the ‘plain’ text of my old posts (in a nice clear coloured indented format amidst a bunch of lots of other old Drupal XML formatted entries – see below) that I could cutnpaste into my WordPress install in MAMP, running in a Safari window.

Plus, I could calculate the date of the post using the above approach via Wolfram Alpha.

The bit that remains is that, obviously, the hyperlinks to old videos and photos are broken and I don’t have them at all as they are probably BLOBS within the old mysql dump file somewhere.

But I don’t care: I have the original text sources now (all the stuff I wrote at the time) and, given that I don’t have 5 million posts (only at least two dozen), I can recreate those images and video files at higher resolution from my video and photo databases (e.g. iPhoto and video sources shot on DSLRs) – which will make the whole thing look a lot better than it used to.

You see, I was emailing these things from Antarctica over a satellite connection, so they had to be severely downsampled.

So that was my solution to a classic data retrieval problem for a CMS ignoramus. It was a bit onerous, but I am now a lot more careful about how I lock in my content to database systems that use specific file structures that I don’t know how to properly interrogate. And I’m not about to undertake a computer science course to figure out how, either.

I am sure there are programmer-types who might laugh at this approach who could use complicated terminal unixy/sql approaches to solve this – but, hey, I’m not one of you (but do feel free to suggest far better solutions!). This worked for me and I got done what I needed done and that’s the point. The posts were readable, cutnpaste-able, and I can make beautiful new high-rez versions of the videos and photos.

Then, as this is now running in WordPress in MAMP on my intranet, I can do a really long term save – like printing the bloody things – and also export the data to whatever public-facing blog I want. Of course, it’s still in a MySQL database, but there seem to be easier export options available to me in this day and age – and they conform to my new WordPress standards, which is also a hosted solution as well as a standalone (i.e. I might expect longer term data-migration support.)

This is a process I’ve struggled with since using Blogger in 2002 and onwards: the continual migration of data across different incompatible CMSs. There seems to be no particularly easy way to do it, but such is life.

I hope this gives the few who might come across this problem an approach to attempt doing it yourself – it’s worked for me.

Oh, and so the whole Wolfram Alpha thing: that was a way of figuring out the  “created” dates of the blog posts contained in the old nodes.xml file:

<!-- Table node -->
        <table name="node">
            <column name="nid">1</column>
            <column name="type">blog</column>
            <column name="title"></column>
            <column name="uid">1</column>
            <column name="status">1</column>
            <column name="created">1123895580</column>
            <column name="changed">1124373591</column>
            <column name="comment">0</column>
            <column name="promote">1</column>
            <column name="moderate">0</column>
            <column name="teaser">Well, here we go. This is my very first blog entry using the Drupal CMS for this research website.

Good luck!

Golf cart camera dolly

October 2, 2010

A camera strapped to a golf cart works, but is too jittery to be useful. It would need better wheels, maybe a track to run on. It could be controlled using a radio-control and steerable wheels easily enough.

Simple camera dolly

October 2, 2010

Experimenting with dolly ideas, I tried out Grandma’s electric cart (thanks Grandma). Its wheels are large, rubber and soft so minmise shake. Running the cart slowly allowed steady dolly shots. Very simple and effective.

Flying fox photos

June 14, 2010

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Uphill flying fox carts wood

June 14, 2010

Our club in the mountains needs about 30 tonnes of wood every couple of years. We cut the wood which is then is delivered to the bottom of the hill. A very effective flying fox and cradle carts it up the hill. The 6mm hawser is tensioned about 200m apart to trees, supported by an A frame at either end, the top one being 4 offset aluminium tubes. The bottom of the 2 cradles can be unlatched to drop the wood at the top. Power is provided by a long rope, wound around a wheel drum on a ute. The ute is jacked up to free the wheel, the rope wound around as a capstan winch. The first cradle is loaded, hauled up, and slid back down. Meawhile the second cradle is loaded and ready to go, and the first cradle lifted out of the way. This system has being working for a few years now, and is reliable and safe.

Kite photography on the beach

June 12, 2010

We went on a holiday last week, and came across a beach on a sunny day with a good breeze. So I set up the kite photography and got some good pictures.

Autopanogiga software stitched them together into interesting panoramas.

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How to make sand flat for paving

June 12, 2010

I’ve paved a few paths and garden areas, but I never knew this trick of making the sand flat, and getting a fall in any direction.

Simply use two lengths of flat bar laid on the sand and tapped down to the finished height. Screed to that level.

Penguins – kite photography – deshaking video

May 31, 2010

During last summer Pete and I went to Cape Denison in Antarctica with the Mawsons Huts Foundation. One of the projects I was involved with was kite photography. This was reasonably difficult in the conditions of cold and high wind, but a surprising number of good images were obtained. These two videos show what can be done with a good camera – Canon SX00IS with CHDK hacking software. I took a video of a penguin colony, and thanks to Deshaker and Virtual dub it is possible to get a reasonable movie. The useful thing about this technique is that the penguins can be photographed from 5 metres or so above their colony, and they don’t mind one bit.

Compare the pre and post Deshaker movies to see how good this software is. The movie was taken on a very windy day where there was a lot of sway in the kite string and camera rig.