Archive for February, 2008

I Like Math…

Monday, February 25th, 2008

…which doesn’t mean that I understand it. However, it does seem to have the uncanny ability to predict how some things will behave and certainly can make come cool looking stuff.

Expanding on the spirographs from the other day, here’s a modified version which will iterate through a range of .1-10.0 for r and R.

Spirograph Generator


Oh! The Places You’ll Go…

Monday, February 25th, 2008

I was messing around with generative drawing for the Processing class I’m teaching…and started playing with spirographs (my bigger brain, ie. Google and Wikipedia, reveals that they are called hypotrochoids).

The algorithms are quite simple:

x = (R - r) * cos(theta) + d * cos((((R-r)/r)*theta));
y = (R - r) * sin(theta) - d * sin((((R-r)/r)*theta));

The results are neat, and mapping the basic variables to keys or the mouse provide a nice way to alter the drawing through iteration. Coupled with the PDF library and some extra code the graphs can be printed out at large sizes. Here are a couple.


Moving Forward

Sunday, February 24th, 2008

What a week. Really busy with projects under deadline, but it’s over…for the moment. Golden Cheetah has only a couple more features that we’re looking to include before the release. I also finally got on my bike with regular frequency this week.

I’m looking forward to focusing more on my classes and riding in the next couple of weeks. The season is fast approaching…

Fun-A-Day 4

Sunday, February 17th, 2008

The fourth annual fun-a-day show was last night at Studio 34 Yoga in West Philadelphia. As always, it was a mad rush to get ready, a blur of an evening then an exhausted aftermath.

Here’s what it looked like compressed to 30 seconds.

Get the Flash Player to see this content.

More features

Saturday, February 16th, 2008

I noticed a thread on the Wattage forum that mentioned a new format for Ergomo CSV files. The poster also mentioned that they hadn’t used Golden Cheetah because they thought it was for Linux only. Anyway, I got a copy of an Ergomo CSV file and got to work on making GC.

It was pretty simple to update. Justin had already wrote the code to read in PowerTap csv files. I just wrote in the logic to determine which flavor of CSV was being read and to parse the data in the way GC expects.

Still need more testing. The only Ergomo CSV file I have has German headers (ZEIT,STRECKE…). Hopefully I’ll get other versions of the files to test.


Saturday, February 16th, 2008

Golden Cheetah is universal! (i hope)

I spent most of the evening setting up my development environment to get Golden Cheetah to compile as a universal OS X application. This would be made easier if I actually knew what I was doing. In the end, I recompiled Qt4.3.1 and QWT5.0.2 as universal before I could move forward with building GC.

Here’s the configure command for Qt (one line):

./configure -static -prefix /usr/local/Qt4.3u-static -make libs
-confirm-license -universal -sdk /Developer/SDKs/MacOSX10.4u.sdk
-qt-sql-sqlite -LD="gcc -mmacosx-version-min=10.4"

I’m using a non-standard install location for the static libraries so I can update Trolltech’s binaries separately. There was some problem with gcc under Leopard, so some special parameters needed to be passed along: -mmacosx-version-min=10.4

qmake’s .pro files needed to have some config variables set. Specifically, I had to add these lines to each of GC and QWT’s .pro files:

CONFIG+=x86 ppc

I was also getting linker visibility issues, which were resolved by additionally adding QMAKE_CXXFLAGS += -fvisibility=hidden to each of the .pro files as well. I don’t know if this is correct, but the resulting application seemed to work.

More testing is needed, but it’s finally working under 10.5 Intel and 10.4 PPC. Forcing the use of the 10.4 SDK and min version 10.4 did something right.

Enough tech…I need to ride.

Almost there…

Wednesday, February 13th, 2008

Golden Cheetah is on the verge of a new release. Sean’s committed Justin and my changes for BikeScore and metric/english preference into the svn trunk. I’ve cleaned up some of the user interface and have compiled an OS X Intel version. More importantly, we now have a desktop icon for the application under OS X…it’s all about aesthetics, really.

We’re discussing the next round of planned features now…it’s exciting.

Golden Cheetah

Saturday, February 9th, 2008

We sorted out the build issues largely, however I still haven’t been able to confirm if the problem was isolated to the target machine or to 10.4 in general. Regardless, the Dr. Phil Skiba’s BikeScore algorithm has been incorporated by Justin Knotzke using a bit of the code I had originally developed for Dr. Coggan’s Training Stress Score (TSS/NP) into unreleased dev builds of Golden Cheetah. Hopefully this will be rolled into the release branch soon.

This is an interesting metric. I’m going to begin to use it in ernest in my training and will compare it the the TSS I have been using.

op art

Tuesday, February 5th, 2008

in preparation for the processing class i’m teaching this spring, i’m reviewing casey and ben’s book which i’m using as a textbook for the course. i noticed a mention of the paintings of bridget riley as influence for a series of images titled “riley waves”. i remember creating a similar optical illusion using hand cut strips of Color-Aid paper long ago in a color theory class.

with the only clue of using beginShape(TRIANGLE_STRIP) mode i played around to recreate the effect. i really like the animation. (click in the canvas to change the animation parameters)

op art

headache resolved (sort of)

Monday, February 4th, 2008

after rebuilding GoldenCheetah every which way I could think of to get it to run on 10.4 Intel, the end solution for this specific case was to upgrade the target computer to 10.5. i’m not satisfied with this, but am too busy with other work to invest more time on it for now.