Steep Speedy Hikes

It started as curiosity. What do GPS tracks say about the ratio of uphill and downhill hiking speeds?

It became graphs of all the hikes I’ve done since ’07 showing speed against the hike’s angle of slope.

Here are the average absolute slope angles on a per-track basis. If the dot’s high up, the hike was on a steep hill.

All hike speeds by track.

Yes, those high tracks before 2012 were steep. Mailbox Peak, Guye Peak, and Wagonwheel Lake, for example. Good stuff. A week after wobbling to the car below Wagonwheel Lake, I was merrily springing up the stairs at home.

Notice the laid back hiking in ’12 and ’13. … Sigh. … 2012 was a lost summer – lost working too much while the sun shone outside. The 2013 hiking season was spent in chemo-land. The cluster of flat hikes at the end of 2013 was me getting strength back by looping Maplewood.

Here are the average track speeds. It shows Scott’s bike a few times in the last couple years. The cluster of 5 kph tracks at the end of 2013 are the flat, Maplewood strolls mentioned above.

All hike slopes by track.

One of the slow speed hikes in late 2014 was up Adams Peak (Sri Pada) in Sri Lanka. Here are how the point-speeds on that walk distribute as a function of slope angle.

Sri Pada speeds by slope.

That hike’s graph really shows the difference between down and up-hill speeds. I “ran” down a lot, but you don’t enthusiastically race straight down 5000 concrete stairs.

Here’s the same sort of thing for Wagonwheel Lake:

Wagonwheel Lake speeds by slope.

As noted below, GPS points are noisy, any way you spin ’em. But the overall fit is OK.

Here are all the tracks’ points graphed as a function of slope.

All hike speeds by slope.

Bike ride speeds tower above the others. The near-level-ground points in the middle of the graph are, in fact, skewed to the left – downhill – to negative slope angles. They don’t look so in this graph for tech reasons.

Finally, here is a PDF containing scalable versions of the all-hike graphs above.

all_hikes.pdf

Note: These graphs were made from “hikified” GPS tracks. Points in a line between two points are eliminated by the “hikify” logic. That logic also combines GPS points near each other. But, even at a filtered, combined point scale, GPS data is noisy.

Python 2.7 scripts in the usual state of repair:

hikify.zip
gps_hill_speed_plot.zip

Really old hospital charges

Scratch paper gathered from Mom included some stiff cuttings of the bottom lines from a Longview hospital in 1973.

old_hospital_charge_01

Here are some numbers:

 

Patient Amount Insurance
3434.15 0.00
7883.24 614.85
12280.31 11351.91
2862.78 0.00
13387.37 3656.97
2239.54 0.00
4516.33 2745.24
2632.35 0.00
12645.13 3542.17

They feel very modern.

Sending ad requests to the bit bucket

To send ad requests from your browser to the bit bucket, a common trick is to use the hosts file to send ad farm HTTP requests to a non-existent server.

A non-existent server can make the browser wait too long for gobs of HTTP requests.

So, give a machine running Apache an interface for an IP address that isn’t used on your local network. 192.168.99.99, for instance. Or 10.252.252.252.

Then add this sort of thing to your /etc/apache2/sites-enabled/200-vhosts file:

<VirtualHost 10.252.252.252>
  ServerName    helload
  DocumentRoot  /var/www/spam_ad_dir/
  ErrorLog      /var/log/apache2/spam_ad_error.log
  CustomLog     /var/log/apache2/spam_ad_access.log combined
  RedirectMatch 403 /* 
</VirtualHost>

Change the IP address as appropriate. And, you can make an empty directory at /var/www/spam_ad_dir/

For amusement, read the spam_ad_access.log.

Fleeting glances

Since replacing my eyes’ lens there have been a few times – every week or two, call it – when I see an hallucination out of the corner of an eye.

They move. Fast. And are gone.

What was that?? A rabbit? A car? A leaf falling where it shouldn’t?

They always seem like … something. Something identifiable.

But then they are gone and forgotten.

Nothing to see here, folks. Move on.

Coupled with more apparent oddities of new lenses – weird depth perception, fluid focus, bright blue world – these hallucinations do show that vision is not a camera.

So, now I wonder – just where in the brain is our GPU? Hey, it’s no new story that what we see in our mind’s eye is highly processed. But some gizmo has to render that highly processed information back in to pixels. That gizmo is impressive. And it’s not surprising the works of such a gizmo would be gummed up when its raw input is changed.

(Yes. I also believe that “gizmo” is a misleading representation of this aspect of the vision system’s architecture. It might make more sense to think of the image in our head as being heavily shopped. With parts of the image variably selected from many shopped alternatives.)

Paper Tape

As can be clearly seen by the octal values, this is a scan of the mylar tape of the Super Wrinkle boot loader for the APS-73 Computer used in Autologic typesetters.

super_wrinkle_boot_loader_in_mylar_small_01

Super Wrinkle, if I recall, was the ultimate boot loader – a worthy successor to the famous Wrinkle loader. Super Wrinkle required the minimum possible switch toggling to be read from the tape reader. Once it overwrote the toggled instructions, it read a more complex, generic, non-hacky loader. This had to be done after any power cycle / reset / program failure / hardware glitch.

The alternative to toggling in the instructions to read an infinite number of (Super Wrinkle) bytes from the tape reader was too expensive for everyday computer use. We’re talking $27 for a mighty, 256 byte ROM chip. That was back when $27 was $27, mind you. One customer built such a device out of discrete diodes to save the cost. The word was it was quite a monstrosity.

Does rotation matter?

Watch a baby get frustrated with toys that encourage them to fit a piece of wood in to a complex hole the piece is shaped for. Or watch a baby try to fit simple-geometry, 3D blocks through the 2D holes made for them in a box.

The question is: Do babies have a hard time twisting things and/or do babies just not “see” the rotation of an object? Or is there something else going on?

My own memory of those fit-the-pieces toys is not happy. I found them boring. And irritating. The danged thingees just did not fit properly! Like they had secret knobs that stopped them from going in to their holes. But I don’t remember having a hard time physically rotating the thingees. They just didn’t auto-rotate to exactly the right orientation as they should have. I was probably thinking, “Good golly, where is NFC when you need it?!!”

Well, luckily, the world moves on. Some years ago, car companies figured out a key should go in both ways. Now, they’ve figured out cars don’t need keys. Just a push-button. Soon, soon, your infant will be able to drive.

So what does a VR headset feel like if it rotates the horizon to always be level with your eye line? … … … As you see it in real life.

CrystaLens

Monday I was sedated and had my big-cataracted, right lens replaced with a CrystaLens by Dr. Jarstad at Evergreen Eye Center in Federal Way.

A bunch of eye-drops, at least one 13 hour sleep, and the eye is starting to see things without a sheet of turbulent water in the way.

The kitchen’s fluorescent lights made one thing very, very clear. Currently, the CrystaLens eye sees a far cooler color temperature. Two of the three kitchen lights were a bright blue in the new right eye, a warm orange in the “normal” eye. Here’s an image with two roughly identical sides on one of my monitors (the right-eye side has a bit of a blue glow on the other monitor).

crystalens_left_eye_01

 

That is, if the left eye sees the left side and the right eye sees the right side, the two sides look pretty close to the same.

The left eye version of this image doesn’t see a huge difference between the two sides. The right eye version sees a stronger blue-ish on the left, green-ish on the right with quite a bit of intensity difference.

There are a number of odd artifacts having to do with surrounding colors. But, we’ll see how things change in the next week or so. The doctor indicated I had quite a bit of swelling so it’ll be some time before things settle down.

But, at least today, the eye hasn’t felt like there’s a chunk of rock in it. That’s a huge improvement.