A hypothesis to test

I have recorded reams of data from paddling:

Everything is keyed on time, using the Time::HiRes perl module. Now I just need to test a few hypothesis:

I do not really believe that paddling is that simple, but I'm looking for some well defined problems to brush up on my skills with R


jack | posted Tue Mar 27 08:43:44 2007 | updated Tue Mar 27 08:45:53 2007 | #
category: outside/paddling

Pretty pictures

On Wednesday, I showed up at practice with my Zaurus, gps, heart rate monitor, and accelerometer.

The new addition to this is the accelerometer, which adds significant resolution to the data. It supports sampling rates up to ~475Hz, but I only had it working at 25Hz (that's how fast it worked reliably with minicom).

As a first pass, I turned everything on and put it in my drybag. I wanted to get a feel for how it all worked.

After practice I loaded up all of the data into R, and set up the data as time series.

A major error source is the correlating of the starting points of the time series. The GPS, and HR monitor are fairly easy to correlate (because they have reasonably accurate clocks onboard). The raw accelerometer output I used didn't timestamp the data. As I was using minicom to capture the accelorometer output, I ended up using the ctime of the minicom capture file. Assuming a capture rate of 25Hz(which it was set to), and the number of samples, I estimated the start time.

I'll write a zaurus application that does this.

A keen observer will note that the accelerometer also isn't calibrated well.

At 25Hz, you can see the individual strokes.

This means it should be possible to systematically analyze what acceleration waveform correlates to the highest hull speed, and thus validate what stroke technique is most efficient.

That, however, is gonna take a schwack of work.


jack | posted Fri Dec 8 16:30:39 2006 | updated Fri Dec 8 16:45:28 2006 | #
category: outside/paddling

A long day

0400h Idea preventing me from sleeping. How to transform a set of distances between points into vectors?
0445h Leave for Vernon
0915h Arrive in Vernon (at Kin Beach)
0945h Welcome FCRCC Novice crew. The completed the short course for the Vernon Freshwater Challange in 2:31. Congrats!
1000h-1200h Race preperation madness ensues. It turns we have 2 teams of 8, instead of 2 teams of 9. This means longer shifts. Whee!
1215h Start the Vernon Freshwater Challenge Long course.
1630h Finish the Vernon Freshwater Challenge Long course.
1700h Load the canoes back on to the trailer.
1800h Depart for Vancouver.
0000h Arrive in Vancouver.

jack | posted Mon Aug 7 00:59:55 2006 | #
category: outside/paddling

April Time Control

Conditions were good for the time trial. There was a bit of a breeze, and a bit of a tide, and it was nice and sunny. There were three of us doing 2 rounds
of the False Creek 5km loop.

About a third of the way into the first loop I managed to find and keep good upwind rhythm, and then turn at Science World and find and keep a good downwind
rhythm.

All told I'm pretty happy with the way it went. As Calvin put it, I should have stopped paddling to suck back a power gel when I was already moving,
instead of when I was turning around and essentially stopped.

I haven't seen the posted results, and I didn't time myself, but the number on the time sheet was "57:11?", which would be good.


jack | posted Mon May 8 13:30:31 2006 | #
category: outside/paddling

Vernon Freshwater Challenge

August long weekend is a good time to be in the Okanagen. Unless you don't have a place to say. Or don't like heat.

My excuse for making the trek out to Vernon this time was the Vernon Freshwater Challenge. The race was on a Sunday morning, so I rode my bike out
on Saturday Afternoon. Meriit when I rode past it.

There was nowhere to stay in Vernon, so I ended up staying up at Silver Star. Although more expensive than camping, it was quiet, and cool.

The Vernon Freshwater Challenge is a fun race: well organized, warm, beautiful location, and a nifty beach start. It is also a change race. Change
races are oddly similar to relays; in a change race there are 9 paddlers and
only 6 of them are in the boat at any time. A escort boat carries the other 3,
periodically dropping a few in the water in front of the canoe. The paddlers
become swimmers, and the swimmers become paddlers. The escort boat then cycles
around and picks up the swimmers. Getting into a boat going 13kph is harder
than it sounds.

Race day started by getting up too early to cheer the women for their 0700h start. Then followed about 4 hours of trying to organize 9 guys for a 4 hour
race: food, water, paddles, and a coach (someone to keep on top of the change
schedule). There was a brief delay of the race start when Steve, the steersman
for our top boat, cut his head open on a car door.

The race went well. We had a good start, we didn't huli, and we beat the women and all of the mixed teams.


jack | posted Thu Dec 1 18:02:21 2005 | #
category: outside/paddling

Cataline pics

I've pruned and renamed Tam's pictures of the Catalina Crossing.

What I'm really waiting for is the pictures Tam took on Niels's camera.


jack | posted Tue Sep 20 11:58:17 2005 | #
category: outside/paddling

Catalina Pictures

Tam's Catalina pictures are up.

Apparently Tam took much better pictures on Niels's camera. Once I get those, I will cull and comment.


jack | posted Thu Sep 15 22:41:52 2005 | #
category: outside/paddling

Catalina Results

Results are up.

To quote Shane:

The 2nd crew was 22nd (Open Spec) and 20 minutes ahead of the last crew...pretty good for a boat that hulied and was DFL early on!

jack | posted Tue Sep 13 11:22:12 2005 | #
category: outside/paddling

Not 31 miles..

I built a route map for the Catalina Crossing using the google
maps pedometer
. Its probably not 100% accurate, but I believe it when it
says that the route is 34 miles.

Tam came along in the escort boat and took a pile of pictures using other peoples cameras. Now just to collect them..

The race went well, except for a huli just after the first change. The first time Ive ever turtled an OC6.

Big thanks to Robyn and Sheila for coaching us, and Dave and Grant for driving the escort boat, and to Shane for organizing the whole damn thing.


jack | posted Tue Sep 13 07:38:01 2005 | #
category: outside/paddling

Catalina Crossing 2005

Yay! Off to Catalina for the races.


jack | posted Thu Sep 8 22:50:07 2005 | #
category: outside/paddling

A weblog by Jack Cummings