Erika Kosina has done a great job of setting this up, and I’m looking forward to meeting more of the local tech community.

Some of the things I’ll be touching on are:

• Why big data is the cool new kid on the block, or why I wished I really knew statistics.
• Crunching big data to filter, cluster, classify and recommend.
• How big data + machine learning == more effective advertising, for better or worse.
• The basics of Hadoop, an open source data processing system.

Hope to see you there!

Unfortunately most of the relevant content I’ve got is for Java programmers interested in using Hadoop. Things I could talk about, based on personal experience:

• A 600M page web crawl using Bixo.
• Using LibSVM to predict medications from problems.
• Using Mahout’s kmeans clustering algorithm on pages referenced from tweets (the unfinished Fokii service).

I’m looking for relevant talks that I can borrow from, but I haven’t found much that’s targeted at the technically minded-but-not-a-programmer crowd.

Comments with pointers to useful talks/presentations would be great!

Check out the interactive version here.

Matt posted a video of the kids having fun at a local school.

Wish I knew how to embed Facebook videos in a WordPress blog posting.

Captains of Crush Gripper

No, I’m not thinking of a new career in strength training – the tie-in is that Randall & IronMind are based in my small town of Nevada City.

After about an hour of work, my battery life was down to less than an hour, instead of the 3-4 hours I was expecting. Hmm, maybe my battery is dying. But I can hear a faint humming noise, which means the hard disk is spinning continuously. And I had trouble putting my Mac to sleep before I left for the parade.

I fired up Activity Monitor, and saw that something called “ditto” was using up 95% of my CPU. Firing up the Terminal, I executed “ps auxwww | grep ditto” and got:

kenkrugler 15193  98.2  0.0    75624   1024   ??  Rs   Tue02PM 3942:21.74 /usr/bin/ditto -xk - /Users/kenkrugler/Desktop/.BAHO26HV

Executing “man ditto” in the Terminal tells me it’s used to “copy directory hierarchies, create and extract archives”. What’s odd is that it’s been running for 3942 minutes, or almost 3 days.

Then I remembered that a few days ago, I’d renamed a .jar file to .zip and tried to expand it, to show somebody the structure of a jar file. But the Archive Utility hung, or rather it refused to finish or quit. So I had to force-quit it.

Which apparently left the underlying “ditto” process running, and what looks like a fully expanded version of the .zip file in a hidden “.BAHO26HV” directory on my desktop. I restarted my Mac, deleted the directory, and everything returned to normal (less 3 hours of battery).

Instead, Jenna came home from school with a sealed envelope they’d left with her teacher. This directed us to a sundial Schmed had secretly constructed on our property.

At 4pm the shadow gave us the digit to use to construct a phone number, which we called for our next clue. Hmm, where can you find the most wheels in Nevada City that aren’t attached to cars? They’d cleaned up that illegal tire dump near Old Downieville Highway. Of course – the Tour of Nevada City bicycle store! After a fun hour of digging up buried hints, figuring out what a Pikachu evolves into (good thing Jenna was there) and reading “Go Dog Go” for clues…

…we found ourselves at the final destination:

Banner Mountain is the highest point around Nevada City & Grass Valley, at 3899ft. During fire season the tower at the top is manned by volunteers.

Jenna & Schmed on the tower stairs

It turns out Cindy & Schmed had been practicing “pair fire-spotting” for the past few months…

Cindy demonstrates good technique

and they’d set up a lovely anniversary party for us at the top. At the end of their 6pm shift, Jenna got to sign off, which pretty much made her day.

Talk about raising the bar – I’ll have to start planning their next anniversary event soon, since it’s only 8 months away.

My initial calculation for the pay-back period was 15 years, due to slightly less-than-optimal roof orientation and some shade from large cedar trees around the house. This was based on the “easy” approach of having a local company handle the entire project, including the rebate.

By paying for consulting to design the system, buying the equipment myself, hiring a contractor to install it, and dealing with the California state rebate program directly, I managed to get the break-even time down to about 7 years. Though at the expense of significant hassle and a few close calls, like the fact that my original inverter couldn’t deal with the (lower) voltage gain from the Kyocera panels I wound up buying.

But back to the title of this post – while working on the design, I searched the net to see if somebody had a way of calculating the optimal angle for the panels on the roof. I found exactly what I was looking for here. Then I noticed that the author of this page is Charles Landau, somebody I had worked with briefly while consulting at Palm. And then I found out that he lives in Nevada City, about a mile away from my brother-in-law.

Now we’re both members of the Nevada City tech lunch group, so we get to talk about solar panels, environmental testing, and open source projects like his CapROS operating system.