Viewing Category: Geeky
This Saturday, November 18, is Barcamp Manchester. I was in the vicinity of a Barcamp in Austin last year, but wasn't a participant. This will be my first time. If I can get a network connection, I'll try liveblogging it.
Doors open at 10AM. We're capping the attendees at 100. There's a little over 100 people registered on the Wiki, we're thinking we'll see about 70% turnout from people who've put their name down. We'll see how it goes.
FOLLOWUP
Here's the flickr pool tagged barcampmanchester.
The conference was a success! About 75 people showed out of the 100+ who'd signed up. We had enough food. I also discovered that (1) my hairline has eroded far beyond what I thought (2) it is time to hit the treadmill and (3) I hate interrupting speakers to remind them about time...next year I'm bringing kitchen timers.
I didn't attend full sessions, though I caught bits of several and am feeling energized. Tired, but energized.
Ian Muir has been busy organizing the first BarCamp Manchester for November 18, right here in Southern New Hampshire. It looks like people are starting to register, so that rocks!
Spread the word! Ian is also looking for corporate sponsors to cover the cost of food and other sundries like shwag.
The poster is comprised of photos I took of stuff lying around my house, composited together quickly (and rather sloppily) in Photoshop before being dumped into Illustrator. The cool windows in the background were created by Joan, which helped get the whole poster rolling when I was stuck...thanks Joan! This part of New Hampshire is known for the old textile mills that still line the river. They have windows that are rather distinctive and tall, and most of the buildings have been converted into high tech office space.
I wasted a couple hours debugging a Kensington Pocket Keypad I had purchased to work with a 3D program I'm using. I use ancient Model M keyboards on all my PCs, specifically the 84-key Space Saver design that lacks a numpad. Geeky notes follow.
PC Keyboard Scan Codes
Every key on a IBM PC-style keyboard has a unique identifier called a "scan code". For complex applications with a lot of functions, it's not uncommon to use the numeric keypad for special uses. So while you might think typing a "9" on the numpad or the top row of keys doesn't really make a difference, they are two distinct keys. Each key has a unique scan code, and software can be written to take advantage of that.
I used a nifty utility called ScanCode Show to tell me what scancodes were being sent by the Kensington compared to the Targus keypad I just picked up. The Targus (model AKP01US, wireless) sent the correct codes. The Kensington sent the codes for the other number buttons at the top row of the keyboard. Functionally, this is OK most of the time, but it is 100% useless for what I need it to do. Back it goes!
It's really too bad, because otherwise it's a very attractive, compact, good-feeling keypad with extra USB ports.
Although I keep telling people I don't do servers, I'm looking into moving a friend's active Phorum-based BBS to a new host. I'm considering FutureQuest as the new host. I'd heard good things about them, though they're a little pricey compared to other plans.
This is a good opportunity for me also to evaluate new hosts for the blog. I'm currently using Pair Networks, who have been awesome for the past 8 years, but their database servers start pooping out when you get over a certain number of transactions per minute, and it's starting to become an issue.
This is the first time I've had to move a WordPress blog from one host to another, so I'm documenting the process. WARNING! GEEKY NOTES FOLLOW!
Different Server, Different MySQL Versions
Conceptually, it is as simple as uploading my current WordPress files to the new server, and then transferring the MySQL database that holds all my posts and stuff. POOF, it should work, right?
As it turns out, the FutureQuest DB servers are using MySQL version 4.0.x, and Pair is using 4.1.x, so I have to downgrade to an older server version.
MySQL Import Woes
There were three easy ways I found that would backup a Wordpress database, which I tried one-after-the-other.
First up was Aaron Brazell's WordPress-to-WordPress Import exporter / importer. WordPress doesn't come with a WordPress importer, so that's what this package adds.
The plugin exports your posts in an extended RSS format, which you can then upload via the import plugin from your browser. Great in theory! Unfortunately, my blog backup is 9MB, which exceeds the 2MB upload cap of this server for PHP. I may try hacking this to read the backup file from a location on disk, but I decided to try another approach.
Next, I looked at Skippy's WP-DB-Backup plugin, which is included with WordPress 2.0, gives you the ability to produce a SQL dump file from the convenience of your admin panel, without all that fussing around with the command line.
So I did this, and then tried importing the dump file into the new server using the standard mysql < dumpfile.sql style approach. It didn't work: 1064 - You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near 'DEFAULT CHARSET=latin1'
Darn! This looked so promising.
I moved on to Lester Chan's WP-DBManager 2.05 plugin, which allows you to do a lot more with your WP database. It uses mysqldump to create a compatible SQL dump file, which you can then use to re-initialize a new WordPress installation. SAME ERROR in attempting to import. DOUBLE DARN!
Downgrading from MySQL 4.1 to MySQL 4.0
After some digging, I found that MySQL 4.1.x added a different way of handling character sets, and this was reflected by the DEFAULT CHARSET command added to the end of the CREATE TABLE statements in the dump file. MySQL 4.0.x has no idea what this is, so it throws an error.
The workaround I found was to modify lines 32 and 36 of Lester's dbmanagerdatabase-backup.php file. I added:
--create-options --compatible=mysql40
...before the '|' character on line 32, and before the '<' character on line 36. The first parameter tells mysqldump to use MySQL-specific syntax for creating the table, and the second parameter makes those problematic DEFAULT CHARSET commands go away.
The Backup Procedure
So here's what I ended up doing:
On the CLONE blog: Install WordPress 2.0.4, plain vanilla, uncustomized. This is the "blank clone" on which my old blog will be imprinted.
Install Lester Chan's WP-DBManager 2.05 plugin on both old and clone blogs.
On my OLD server: I edited the plugin as described in the previous section, so the database backup file created would be compatible with the new server. Again, my current server uses MySQL 4.1, and the new server uses MySQL 4.0.
On my OLD server: Created a database backup with the patched version of Lester's plugin. Yay!
Then, copy the database backup to the CLONE server. It's in wp-contentbackup-db if you've successfully installed the DBManager plugin; just copy it using FTP or SCP to the same location.
Preparing for Restore
First of all, my CLONE server has only a numeric IP address, not a domain name. I don't plan on transferring the davidseah.com domain over until I make sure everything works. So the URL I use for it is, for the same of example, is http://192.168.1.100.
WordPress keeps track of your blog's URL in the database table, and uses that to generate links to various parts of your blog. When you do a database restore with DBManager, it overwrites your entire database, including that blog URL setting. When that happens, you won't be able to use the admin page, because you'll be redirected to your OLD blog everytime you try to login.
To get around that, you need to be able to edit the database directly and reset the BlogURL setting. I installed PHPMyAdmin on the clone, to be ready to edit the database manually when I did the database restore.
- To the CLONE server: Copy the database backup file to the
wp-content/backup-db folder, where DBManager looks.
Now you're ready to restore the database.
The Restore Procedure
On the CLONE server: Copy all your plugins, template files, and so forth over to the new WordPress installation.
On the CLONE blog: Go to the admin page and click the DATABASE tab that DBManager has added. Go to the MANAGE BACKUP DB tab, and choose the database file to restore (you did copy it to the right place, right?).
Restore the database by clicking the RESTORE button! If everything goes well, you'll see a SUCCESS message. Congratulations! Your database has been cloned onto the new wordpress installation!
Visit the cloned blog server and see if the home page works. It's probably messed up in some ways if you've forgotten to transfer everything over, and you'll find that you keep getting re-directed back to the old blog if you click on anything. That'll be fixed next.
On the CLONE server: Run the MySQL Administration Tool of your choice. Using PHPMyAdmin, I went to the wp-options table and clicked BROWSE. I edit the siteurl option value to point to the CLONE server (not the CURRENT blog).
Here's an example:
My old site is davidseah.com. My new clone site is, say, on a local server 192.168.1.100, and WordPress is installed in a directory called wordpress. The new siteurl (at least for now) is http://192.168.1.100/wordpress, so that's what I should set the siteurl to. Your new webhost should have provided you a URL that you can use to FTP files to, so just use that.
You should now by able to login and visit the CLONE blog's admin page. Go to Options and change BLOG ADDRESS so it's also pointing to the new server for testing.
After all that, the cloned blog seems to be working, but I won't be able to tell what genetic defects may be lying dormant until they manifest. Database performance seems a little sluggish to me, so I'm not sure if the way that I performed this database move somehow messed up the DB. Maybe some MySQL guru out there can give me some pointers.
Next Steps
Before I move everything over, I need to make sure that my .htaccess is set up correctly, get ALL the downloadable files moved over, update my basecamp FTP settings, and also ensure that my new email addresses are set up on the new server. What a pain in the butt!
My DNS is handled by another registrar, so I should be able to just change the nameservers when I'm ready and see what happens. If it doesn't work out, I can just switch the nameservers back, and resume operations at my current host.
UPDATE:
- My Server Move Log, which also details the different way I moved the database with straight
mysqldump and mysql restore commands from the shell.
A few days ago I wrote about reacquainting myself with mathematics. What started out as a mild recollection of past educational experience ended up raising negative feelings that flapped around my consciousness like angry ghosts. A buddy pointed this out, and after some reflection I laid them back to rest; there's no sense in remaining angry about the past.
While Math had been a source of frustration for me, it wasn't due to the math itself; it was the clouds of confusion surrounding the practice of Mathematics that so confounded me. This was exacerbated by my insistence on understanding something before doing it. Now that I know that there's something good to be said for "learning to recognize and reproduce patterns" before understanding something, I am a lot more interested to tackling mathematics once again.
So here is how I'm seeing the challenge:
- I like the mysterious qualities of Math, and want to be more fluent with the ideas and concepts behind that.
- To do that, I'll need to reconstruct the knowledge for myself, so I can have a clear picture of the relevant facts, principles, and standards of practice.
- However, there are barriers to reconstruction inherent in the presentation of the material: spotty instruction, missing/misunderstood key insights, ambiguous writing in textbooks, and misleading illustrations and diagrams. I groused about this at some length in my earlier post.
Turning the Tables
When I was a kid, I hated it when the facts weren't clearly presented. Today, I have much greater insight into how I learn, and am excited about trying to fix this perceived deficiency in my educational background. In fact, I could make this into a role playing game by thinking of education as a crime scene, where terrible wrongs have been committed against learning! The crime scene is a confusing, muddled puzzle: ambigious wording in textbooks obscure the true relationship between the facts, if they are indeed correct and unbiased to begin with. Key steps are mysteriously withheld, or buried somewhere in the back of the book. Upon cross-examination, key witnesses who spoke with confidence on the scene crumple in the face of sterner questioning.
Yeah, I'm totally going to be a Math Scene Investigator! I already am thinking of the cool notebook I'll get for it!
The Math Scene Investigation Process
Concidentally, I had stumbled upon the Taylor Series Expansion entry on Wikipedia a few days ago. I remember the Taylor Series as being a particularly odious waste of my time in high school, embodying all the qualities I didn't like about math:
- It expanded simple functions into VERY LARGE ONES...seemed like a net loss to me at the time.
- It introduced notation that was tedious to write out when showing your work, though I actually did like drawing those ziggy E things a lot.
- I had no idea really what it was good for, and because at the time I thought math was supposed to be about understanding rather than replicating process, I was very frustrated. The beauty of math was unknown to me.
The Taylor series is a good candidate for the Math Scene Investigative Process, which is proposed below!
Divine the modus operandi of the Mathematics
This is right out of the crime scene reconstruction article I was reading. I pulled up the Wikipedia entry and let it flap its gums for 8 paragraphs of irrelevant detail; they were descriptive facts, but not helpful at all in understanding WHY the Taylor Series even had a place in Mathematics to begin with; I really wanted the big picture first. If I don't know what something is for, how can I evaluate it? Instead, the article told me "what" it was, in terms of mathematical detail. That doesn't really help.
Around paragraph 9, the article came clean: by breaking down a difficult-to-transform function into simpler components, one can actually transform things more easily. That is pretty cool, just not in the context of high school mathematics; for me, it was just another one of those lame exercises you need to do that cramps up your hand and uses up a lot of paper. It's only NOW that I can understand that there's actually some kinds of interesting analysis buried in there; the harmonic analysis, for example, is what's behind all those cool MP3 Player spectrum analyzer displays and other cool digital signal processing tricks. But I digress...I have a little bit of the story now: The Taylor Series has the power to break down tougher calculations into easier ones, a special kind of mathematical solvent. And there are all kinds of interesting side properties that opened up entire new fields of analysis. Pretty serious stuff. Time to move on.
Reconstruct the Facts and Events of the Mathematics
Apparently, I had stumbled in the middle of a pretty serious piece of mathematics; a kind of universal solvent that has far-reaching implications throughout the field, with fingers in modern computer consumer technologies. I would have to step carefully; this was no two-bit axiom I was dealing with.
The rest of the Wikipedia entry turned out to be pretty dense. If the first 8 paragraphs were hard going, paragraph 10 and beyond were incomprehensible, filled with self-referential assumptions and inside jargon. It was a jigsaw puzzle that I would have to unravel piece by piece, reconstructing more than just the Taylor Series knowledge, but its relation to other fundamental players like Power Series and who knew what else. The material certainly wasn't written to explain, in nice bite-sized chunks, what the heck was going on to a newbie MSI like me. Still, it's my job to wade in and extract the real story. If there was a tome called "A History and Timeline of Mathematical Insight and Philosophy", that would help a LOT. Instead, I would have to do things the hard way to figure out what the math was supposed to be telling me. That meant tracking down and explaining every piece of detail on the page, from the funny notation to the significance of every fact. Some of it, I imagined, would be irrelevant in the big picture, but even the tiniest shred of evidence might shed light on another mathematical principle.
This would take some time. I decided to move on to something else.
Interview the witnesses and get their testimony.
Who are the witnesses? People who actually use or teach the mathematics. By talking to them, I'll gain a better picture of what's happening in the world of the Taylor Series, and probably mathematics in general. That perspective will allow me to put together more pieces of the puzzle and form working hypotheses as I build my case.
It's a known problem that witnesses are notoriously unreliable in their observations, and are subject to biasing influences that make their testimony subject to unintentional falsification. A seemingly-confident witness at the scene may crumble in the face of sterner questioning; I've seen this happen over and over. It's important, though, not to hold that against them: people generally mean well, and their testimony and experience provides important clues in understanding just what happened at the crime scene. If anything, you'll be getting new ideas from those witnesses, so treat them nicely.
Still, I have to remember that their testimony, no matter how well-intentioned, may have some flaws or misinformation in it. It's my job to piece together a story that makes sense to me, is supported by the facts as they have come out, and explain the modus operandi of the mathematics. And...it's all got to convince a real math teacher that I have a strong case.
Another challenge is that it's very hard to explain things, especially to someone who isn't familiar with your work and the context in which you perform it. Teachers will have an advantage, as an "expert witnesses", but even their testimony may be inaccessible or flawed. Like I said, it's tough to keep all those details straight. I've got my job cut out for me.
Put it all together
This is one of the best parts of Monk, when he gets to explain how everything fits together despite his debilitating neurosis. Um, I'm not quite there yet with this Taylor Series thing...the investigation is just beginning!
Wrapping Up for Now
Essentially, I'm thinking of approaching Math without the skepticism I've had in the past. Now that I'm older, I'm confident that there is some logic underneath all the obfuscating jargon and material; I just need to treat it like evidence at a crime scene. In the past, I had assumed that everything printed in a book or came out of teacher's mouth was guaranteed to be 100% accurate and true, and if I could not literally understand it there was probably something wrong with me. I know now that understanding comes in many forms; by taking a more investigative approach to with the assumption that the facts are not out in the open, I may be able to make some additional strides.
There are a couple of important resources I have now that I didn't have then:
The Mathematics Wikipedia Entry, from which I can skim the world of mathematics to build my own "big picture" view of how it's all related.
Access to Mathematic Frameworks for all 50 states, a byproduct of the trend toward National and State Standards in Curriculum. For the first time, I've been able to discovery just what we're supposed to be learning, and why. That's important context to have, representing a "pragmatic view" of math education in this country.
It would be interesting to look at a real college-level mathematics curriculum, for people who major in it. I'd be curious to find out how it's different. I guess I need to track down some real mathematicians. Anyone out there?
