Cream teas and pasties

Yes, I'm behind. We've finished this weekend's tourism before I've even documented the last one! Last one was less touristy though - on Saturday we had a morning-tea visit from Rupert, Cath, Amy, Ana, and Phimi on their second last day in the UK, and then on Sunday, we caught up with them again at Coventry Cathedral - Rupert's old stomping (beating?) ground. After saying goodbye there, we explored the Transport Museum for a few hours.

The working week was relatively normal. I might remember some highlights later. I enjoyed helping out with the school orchestra practice on Thursday lunchtime, and then we had Community Choir in the evening.

This weekend, we left Malvern at around 3:45pm on Friday, and rushed through the Upton diversion (still flooded!) to the motorway, and headed to Devon for our Southwest holiday weekend.

Finding the Plymouth Holiday Inn without a map wasn't too hard, but we did resort to a phone call for assistance. We gorged on a (included in the package) 3-course dinner. We hadn't really recovered from that when value-for-money demanded a similar approach to the full breakfast on Saturday morning. We didn't really need lunch!

We headed west to Cornwall, over the Torpoint ferry, along the south coast to our first stop at Looe, a picturesque little historic fishing village. Just when we'd decided that this was the highlight, we made it to the next village, Polperro, which was even cuter.

We hadn't been sure about whether to visit Eden - having received contrary advice about suitability for children. We were glad we drove in to see from the outside. Perhaps one day we'll go back and actually go inside. They are trying to establish some self contained ecosystems.

We continued along towards Lizard (pictured), the most southerly point of the country, where there were some nice cliffs and waves crashing onto rocks, etc. We continued along to St Michael's Mount, at Marazion, just near Penzance. We walked across, the tide being low, but the castle and grounds etc were closed, so there wasn't really much to see or do. We thought about trying to fulfill the "Cream Tea" mandate. But the place we chose had too little "atmosphere", so we aborted and decided to head towards Lands End. The geography was good, but there were no tea shoppes open. There was just enough daylight, we decided, to reach St Ives, so that's where we zoomed to next. It was a delightful little place, and we had a nice little stroll along the foreshore, and managed to tick off another two local culinary requirements - ice creams (despite it being rather chilly) and pasties, which we ate in the car on the way back to Plymouth. We managed to visit the hotel's pool and gym to try to prepare ourselves for the next day's prandial onslaught.

Today, Sunday, we tried to explore the Plymouth shoreline. But during breakfast, we discovered that we were being pea-souped in the fog. While waiting to be seated at our table, we saw a big ship heading towards the harbour. But by the time we were at our table, all we could see was the tip of its funnel gliding past - accompanied by several blasts on the foghorn. After checking out, we braved the chill to take a look at the various swimming & diving spots.

Although we had been planning to head back to the north coast to visit Padstowe etc, we decided that it would be better to explore Dartmoor. It was quite delightful, although closer to lunch time many of the car parks were full as people were taking short strolls to the tops of various nearby tors. We found some delightful rivers (East Dart, West Dart) and bridges, and storybook Widecombe-in-the-Moor village, where we bought lunch in Ye Olde Inn, and nearly found a suitable cream tea. But we decided afternoon tea would be better, so we zoomed off to Torquay to look for Fawlty Towers. We didn't see that place, but again had a nice walk along the shoreline, marina, and park (pic). This time, we did manage to get our fix of clotted cream. And wasn't it good! (May have to reschedule tomorrow's cholesterol test.) We followed the coast through Dawlish, Exmouth, Exeter, and then straight up the M5 to be home at 6pm.

I think it's time to have a rant about milkshakes. I don't like to admit it, but I normally indulge in a milkshake or two a week at home. Sometimes more. And there are some places that serve good ones (Donut King), and some that don't (Wendys, Hungry Jacks/McDonalds, the shop at Moore on the Brisbane Valley Highway). But milkshakes here are (a) nothing like what we have in Australia, and (b) extremely diverse. I think the first one I had was in Ledbury, at the Internet cafe. They made that one with ice cubes, milk, and some kind of flavour in a blender. It's probably the closest to what I'm used to. Today's was more like a cold "hot chocolate" - no froth, no ice-cream, and a weird, almost tannic flavour in the dregs. I don't know how they justify the term "milkshake". Anyway, I will continue my hunt for a decent UK milkshake.

It felt like quite a busy weekend: much more like what we did on our backpacking trip (14 years ago) than we had expected to be able to manage with daughters in tow. But we managed to keep them smiling most of the time too, so I have to describe it as a successful trip.

And here's a question for the lawyers: Am I allowed to take a photo of a sign that says "Sorry no photos"? This was a candle shop in the Torquay Pavilion that was closed at the time.

Evidence, support, plausibility, belief, probability.

I've been reading about mathematical theories of "evidence" - how one should draw conclusions based on different types of (perhaps conflicting) evidence. Dempster-Schafer seems to be the big name, although there are a few offshoots from this that deal with different areas where DS doesn't seem to produce intuitively correct outputs. I find it interesting that "science" is so fundamentally based on the concept of experimental support for theories, but that there isn't a good single theory for describing how evidence supports conclusions.

If you type Dempster Schafer into Google, the first result is a DSTO report, which outlines the concepts nicely, and has a good comparison with Bayes' probabilities.

Although I'm a Wikipedia fan, its article in this area isn't so good, I don't think. The best thing was that it pointed me (in the last reference) to a very clearly written Masters thesis which sums it all up nicely.

Oh, and by the way, it is actually work-related! I feel lucky to be able to read about such interesting things in my work, but a bit embarrassed that I wasn't already aware of such things.

Software List

The new computer is back. I've shrunk some partitions to leave room for linux. I've set up AVG (I need to use Trend for work purposes, but don't have the serial number yet, so I'll use AVG until I do), and I'm using Google Pack to install a batch of stuff.

I think I'll use this blog entry as a record of significant software that I want to be able to reinstall. It therefore counts as a recommendation, although your needs might not be the same as mine.

• AVG Free Antivirus
  
• Google Pack provides Google toolbar, Google desktop, photo screensaver, Picasa, Firefox, Spyware doctor, RealPlayer, Skype, Acrobat Reader, and StarOffice
• Google Earth for when Google Maps aren't good enough
• Java (latest JDK, plus tutorial, source, and API docs)
  
• MyEclipse Software development environment, with the following plugins:
• Subclipse plugin for Eclipse (not forgetting to include the Mylyn and Buckminster things in the Europa discovery site)
  
• FormatOnSave plugin
• MiKTeX - Windows LaTeX distribution
• Texclipse - makes LaTeX so much easier to use.
• Checkstyle plugin - not essential, but good for industrial strength collaborative projects.
• MySQL database
  
• CutePDF Free PDFWriterPublish Post
• 7-Zip Decompresser/archiver (Why does windows take 5 hours to decompress java source Zip file, when 7-Zip only takes a minute or so?)
• The latest flash player - probably easiest to go to YouTube to have the browser load it automatically.
• Hugin and Autopano for image stitching
• Audacity for audio recording and editing
• Putty for ssh.
• Workrave for preventing RSI
• WinMerge for comparing and merging text-ish files
• PDFSAM for splitting and merging PDF files.
  
• GIMP - especially for making backgrounds transparent
• Inkscape for filling in PDF forms and other vector graphics
  

Software installation

I don't have an enormous amount of software to install, but enough to want some help.

To explain: my new laptop came back from the warranty repair today. After having taken so long, I imagined that the repairs may have been complex. So I was a little disappointed to see that all they'd done was replace the hard disk. Maybe they did extensive diagnostics and found that the disk really was the problem. They haven't told me. Maybe they will if I ask.

But now I have a brand new installation of Vista. I could go ahead and start configuring it all. Maybe I should reformat it so that I can have a linux partition. Do I want to risk difficulties in the Vista re-installation? I should be able to download any Asus utilities from the web. Hmmm.

But the blog refers to the various free/open source software that I use - mysql, Google earth, open office, audacity, myeclipse, and a host of libraries etc. Wouldn't it be great to just submit a list (saved in a backup) to an installation tool, and have the computer automatically download all the right stuff. Easy in linux, but I'm not aware of such a tool for Windows. Maybe I'll search.

Cheese floods

It was nice to see snow on the hills on Saturday morning. There wasn't any left on the roads when we took Steph to school and back. But I went for a ride across the tops of the hills between the Wyche and British Camp, and it was (in the words of one passer-by) "a bit treacherous". Hearing the ice cracking under the tires was like riding over bubble-wrap. There were some parts where I couldn't get enough traction, and had to walk - even that was difficult in one part. But the views from the top were spectacular - a wonderfully clear morning.

In the afternoon, we decided to catch the train to Hereford for afternoon tea. We pottered around the shops, and eventually located some slippers for Helen. I stayed on for Evensong (Murrill in E, Howells Here is the little door).

Sunday's destination was Cheddar. Non-English folk may think that this means we were heading to a cheese shop, but we were actually aiming for a gorge and some caves near the town of Cheddar, just south of Bristol. We encountered a diversion around the road to Upton-on-Severn, which was on its way to becoming Upton-in-Severn. It seems that the snow and rain from Friday night was having quite a significant effect! The motorway driving was rather bland, and we got to Cheddar in just over 2 hours. The guide at the cave entrance explained apologetically that the caves were flooded, and therefore closed. That dampened our spirits somewhat. We climbed to the top of the hill and up the lookout tower, and went to the cheese shop for a tasting. (The factory visitor room was closed too.) Lunch was a relatively economical fish and chips, along with a discovery that faggots involve offal.

On the way home, we stopped at Wells and (in two shifts - Christopher asleep in the car) went to explore the Cathedral - home of "the oldest mechanical clock with original dials in the world". We also peeked at the ruins of Glastonbury Abbey through the fence, not judging the expenditure of approx £15 for three of us to wander around in the drizzle for 5 minutes to constitute good value.

There was more flooding evident between Worcester and Malvern on the way home. We saw several usually-sheep-filled fields that were now lakes, and we wondered if the sheep were good swimmers.

Possible holiday route

Here's a little map of a possible Easter driving holiday. Budapest, Salzburg, Freiburg, St Anton, Venice. I won't leave this map on the blog for a long time.


View Larger Map

A light dusting

You'd hardly know it where we are. On the drives to and from school this afternoon, as we went over the hill the rain became snow. At our level, you could tell by the way it was flying around in the headlights that it was either very windy rain or there was some snow in it. But the top half of the hill had snow settling on the ground, and the road at the very top was completely white.

I wonder whether there will be any left by the morning - it's supposed to be clear and cold, so we may be in luck.

Did you notice that I've started putting labels on the posts, to help you find just the ones you like? Click on your favourite category over on the right to narrow your view.

Installing Roller

Am I allowed to write about the opposition (a different blogging tool) here? I decided yesterday that I needed to install a mediawiki and a blog site at work. It wasn't feasible to use an Internet hosted site.

I've read blogs supported by heaps of different engines, but I've only ever used this one, and I've never installed any. I decided that Wikipedia might have info to help me choose a good piece of software. With endorsement from Sun + Apache, Roller must be good.

Installation

My trial system was an old 1.8GHz machine, on which I've installed Ubuntu. Although there was a promise of a 5-minute install, it took hours.

In the end, there were two main things I did to make it work. If only these had been in the instructions!
1. Turn tomcat security off
2. Create a directory /usr/share/tomcat5.5/roller_data (well actually a symlink to /var/roller_data)

So here's the story. There were a number of symptoms that led me to these steps.

There were some errors in catalina.log suggesting that the roller-startup.log could not be created. I tried putting log4j configuration properties into the roller-custom.properties file, but it made no difference. I tried modifying the log4j.properties file inside the webapps directory, and then I started getting different errors.

I decided that the roller-custom.properties wasn't being read. But still errors like this:

Caused by: java.security.AccessControlException: access denied (java.io.FilePermission roller-startup.log write)

I set the log4j.propeties file to be more explicit:
log4j.appender.roller-startup.File=/var/log/roller/roller-startup.log

Then I added a permission to the tomcat policy file:

grant {
permission java.io.FilePermission "/var/log/roller/-", "read,write";
};

The final step in getting the log file was to create the /var/log/roller directory, chown it to tomcat55, and set 755 permissions. Hurrah! Now after a /etc/init.d/tomcat5.5 restart I was getting a roller log.

I found that there was another access problem with ehcache - it wasn't able to create it's diskfile properly. So I used the ehcache properties file to say explicitly where I wanted the cache to go (/var/cache/roller), and then granted the necessary permissions. (Finding the requirement for delete took a little while too!) This took a lot of messing around, because it seems just this first permission wasn't enough:

grant {
permission java.io.FilePermission "/var/cache/roller/-", "read, write, delete";
};

I also had to add a permission for roller to read the /var/cache directory as well:

grant {
permission java.io.FilePermission "/var/cache/-", "read";
};

Great, now the ehcache problem is gone. The next problem is connecting to the database. There was no explicit java.security.AccessControlException - the log just showed this:

INFO  2008-01-11 11:55:07,042 DatabaseProvider:successMessage - SUCCESS: Got parameters. Using configuration type JDBC_PROPERTIES
INFO  2008-01-11 11:55:07,042 DatabaseProvider:successMessage - -- Using JDBC driver class: com.mysql.jdbc.Driver
INFO  2008-01-11 11:55:07,043 DatabaseProvider:successMessage - -- Using JDBC connection URL: jdbc:mysql://localhost:3306/rollerdb
INFO  2008-01-11 11:55:07,043 DatabaseProvider:successMessage - -- Using JDBC username: roller
INFO  2008-01-11 11:55:07,044 DatabaseProvider:successMessage - -- Using JDBC password: [hidden]
INFO  2008-01-11 11:55:07,061 DatabaseProvider:successMessage - SUCCESS: loaded JDBC driver class [
com.mysql.jdbc.Driver]
ERROR 2008-01-11 11:55:07,508 DatabaseProvider:errorMessage - ERROR: unable to obtain database connection. Likely problem: bad connection parameters or database unavailable.
FATAL 2008-01-11 11:55:07,510 RollerContext:contextInitialized - Roller Weblogger startup failed during app preparation
org.apache.roller.weblogger.business.startup.StartupException: ERROR: unable to obtain database connection. Likely problem: bad connection parameters or database unavailable.
    at org.apache.roller.weblogger.business.DatabaseProvider.(DatabaseProvider.java:148)

I checked that I could log into mysql with the username and password - no problem. I wrote a small java app to test programmatic connectivity. No problem. Guess an access control issue: look for java permissions to allow connections, and add the following to the policy file:

grant {
permission java.net.SocketPermission "localhost:3306", "connect,resolve";
};

Database connectivity fixed. I added a similar permission for localhost:25 to get past mail configuration errors.

The Tiles problems were harder:

FATAL 2008-01-11 11:55:07,542 TilesListener:contextInitialized - Unable to retrieve tiles factory.
org.apache.tiles.TilesException: Unable to retrieve init parameters. Is this context a ServletContext, PortletContext, or similar object?
    at org.apache.tiles.factory.TilesContainerFactory.getInitParameterMap(TilesContainerFactory.java:352)
    at org.apache.tiles.factory.TilesContainerFactory.getFactory(TilesContainerFactory.java:143)
    at org.apache.tiles.factory.TilesContainerFactory.getFactory(TilesContainerFactory.java:122)
    at org.apache.tiles.web.startup.TilesListener.createContainer(TilesListener.java:88)
    at org.apache.tiles.web.startup.TilesListener.contextInitialized(TilesListener.java:57)

I spent some time trying to learn about tiles, but gave up. I decided that most people must install tomcat with security turned off. I looked for a way to do this, and found in /etc/init.d/tomcat5.5 there are a couple of lines

# Use the Java security manager? (yes/no)
TOMCAT5_SECURITY=yes

So I changed the yes to a no, and restarted tomcat. What a difference! Finally, the tomcat manager showed that the application was starting up. I clicked on the [/roller] link, and after a few seconds, there I was - a real roller page, offering to configure the database for me. I clicked configure, and it seemed to whirr and clunk for a few seconds.

The next page that came up was a 500 server error. Checking behind to make sure nobody was looking, I just pressed the Reload button on the browser, and I was offered a page asking whether to create a user, a new blog, or modify system settings. I chose to create a new user, but then was informed that the administrator had blocked creation of new users. Clearly a problem.

Decided to revert to a clean roller.war, without any of my fiddles. Also dropped the database inside mysql and started that again. This time, it was sure to work as advertised. Well, nearly. I was still unable to create new users. Check the log file (now /var/log/tomcat5.5/roller.log, and find this error:

ERROR 2008-01-11 14:25:58,853 IndexManagerImpl:initialize - java.io.IOException: No such file or directory
ERROR 2008-01-11 14:25:58,894 IndexManagerImpl:getFSDirectory - Problem accessing index directory
java.io.IOException: Cannot create directory: /usr/share/tomcat5.5/roller_data/search-index
    at org.apache.lucene.store.FSDirectory.create(FSDirectory.java:138)
    at org.apache.lucene.store.FSDirectory.(FSDirectory.java:128)

I wasn't going to look into lucene. I tried just creating the /usr/share/tomcat5.5/roller_data directory, which was actually a symlink to /var/roller_data, dropped and recreated the database, started again.

At last, success!

Using Roller

I'm not going to write too much here. I'm very new to Roller, and I'm sure I haven't explored all the options. And when one is familiar with one system, it can sometimes be hard to appreciate the complexities of another. In my case, the initial attempts were somewhat more complex than I am used to. I didn't notice any wimpy wysiwyg type support for adding links and formatting: just a couple of filters for preserving linebreaks. I had to type my own <a href=... > details in. Maybe this one (Blogger/Blogspot) really is better, or maybe I just need to set up Roller a bit more, and understand how to use it. Stay tuned for further reaction.

Dropping marbles, skipping lectures.

A nice Freakonomics post led me to see what happens when you drop a marble in a sandpit. Check out the videos showing how these physicists attract their future students. They should have no problems.

A related Freakonomics post attracted a comment describing auctioning the rights to skip lectures.

Horsing around

I left home at 5:50am to walk to London (via Malvern Link Station). While I was away, the last day of school holidays was celebrated with a visit to the local horse riding stables: Guiness Park Farm. They asked to ride the largest horses available, as you can see. (As usual in this blog, click on pictures to enlarge them.) Although there had been showers/drizzle forecast for the whole day, it didn't rain here this morning, so they were led around a whole farm circuit, which took around 45mins. Stephanie and Helen both seem to want to go back.

Christopher didn't get a turn on a biological horse, but did manage to locate a metal one, which seems to have made his day.