Driving times rebooted

Having paused for over two years, I’m back thinking about my old obsession: how to map travelling time. I have repeated the map I made for driving times in the UK, but this time starting at the Cherry Creek Shopping Centre in Denver, Colorado.


High resolution image available here. Suggestions for how to create isochrones gratefully received!


Speed check


Using successive Google timeline points, provided they are less than 10 minutes apart, I created a map of my speeds. Red tracks are slow, green are fast. Blue are really fast.

A police officer’s guide to my speeds:

  • All of my speeds are below the speed limit for the vehicle I was using.
  • My skiing speeds are extremely fast, until I skied with Eddie, and then they were slow.
  • The blue section on I-25 North of Denver is when I attached wings to my car, a la chitty chitty bang bang

Making tracks

Last post we saw how our benign overlords friends at Google have been tracking my phone. Joining the dots creates tracks showing where I’ve been (shown here with and without a context map).  I have only created tracks when points are less than 30 minutes apart, which means that they adhere quite well to the road network. It also explains why some of last week’s black dots have disappeared.

A stalker’s guide to my life:

  1. The two cluster in the South-West are Breckenridge and Keystone ski resorts.
  2. Denver is the city on the Eastern edge of the map is Denver. The I-70 interstate (motorway) connects Denver to the mountains.
  3. I quite like Boulder (NW of Denver)

How to destripe a panorama

Problem: This image of the Kepler Track, New Zealand (taken by my brother) has vertical stripes where the automatic panorama mode on his camera has adjusted to changing lighting conditions. How do we remove the stripes?


Kepler Track, New Zealand. (c) MDS

Step 1: Read into numpy using matplotlib.image

Step 2: Split into component bands (in this case red, green and blue)


Step 3: For each column of the image, sample the surround bit of sky


Step 4: Compare the sampled area with the sky of the column. If there’s a difference correct the whole column.



Step 5: Repeat for the full image


Step 6: Recombine the bands


Step 7: Compare and enjoy


Trump homogeneity test

Does Trump’s face cluster with that of the other Republican candidates?

1. First take your trump:


2. Build a grid over his face:


3. Repeat for all of the rest and measure some textures. Cluster these textures (in PCA space):


4. Find anomalous areas (areas that didn’t cluster)


5. Build a big wall around anyone with any anomalous cells.

The Ballad of Billy the Kid


Billy Joel’s The Ballad of Billy the Kid (youtube) visualised:

From a town known as Wheeling, West Virginia
Rode a boy with a six-gun in his hand
And his daring life of crime
Made him a legend in his time
East and west of the Rio Grande


Since Billy Joel hasn’t specified the exact area in which Billy the Kid was a legend in his time, I have assumed the drainage basin of the Rio Grande. There is a large uncertainty associated with this.

Well, he started with a bank in Colorado
In the pocket of his vest, a Colt he hid
And his age and his size
Took the teller by surprise
And the word spread of Billy the Kid


I have chosen the First Mountain Bank, Leadville, CO as Billy the Kid’s first crime. I expect he’d travel there along the route of I-70, as otherwise crossing the Continental Divide in Colorado is tricky, even if you have a Colt / six-gun, which they all do in Leadville.

Well, he never traveled heavy
Yes, he always rode alone
And he soon put many older guns to shame
And he never had a sweetheart
And he never had a home
But the cowboy and the rancher knew his name


Well, he robbed his way from Utah to Oklahoma
And the law just could not seem to track him down
And it served his legend well
For the folks, they’d love to tell
‘Bout when Billy the Kid came to town


I’ve planned his route from Utah, Utah to Oklahoma, Oklahoma, as they are both so good they named them twice. There are three sensible routes (suggested by Google). It seems most likely that he would rob his way via the region in which he became a legend in his own time, but the I-70 route would be more familiar and he could pop into his bank for another withdrawal.

Well, one cold day a posse captured Billy
And the judge said, “String ‘im up for what he did!”
And the cowboys and their kin
Like the sea came pourin’ in
To watch the hangin’ of Billy the Kid

Billy Joel then goes on to talk about another Billy, but that’s a different story.