444 reputation
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bio website jasondavies.com
location London, United Kingdom
age
visits member for 2 years, 11 months
seen yesterday

Jun
27
comment Issue with using TopoJSON server API to return TopoJSON object with properties
You need to make sure you're using version 1.6.11 or later (latest is 1.6.14 at the time of writing). The API for property transforms changed slightly in 1.6.11.
Jan
15
awarded  Popular Question
Sep
17
awarded  Yearling
Jun
3
comment ST_Distance is not delivering right results
The URL parameters simply do not reflect the positions of the points; the URL only specifies the centre of the browser window, and the zoom level (position of one of the corners). To get the positions of the points, you need to use LatLng markers, as I mention in my answer.
May
28
revised ST_Distance is not delivering right results
Add note about precision and loxodrome.
May
28
comment ST_Distance is not delivering right results
No, Google Maps is truncating the number to one decimal place, so you need to include a margin of error. If you click "show options" and pick "km", it shows "1.8 km".
May
28
comment ST_Distance is not delivering right results
OK, I finally found the right coordinates by dropping LatLng markers, and this agrees with Google. See edited answer.
May
28
revised ST_Distance is not delivering right results
Finally found the right coordinates!
May
28
revised ST_Distance is not delivering right results
Fix coordinates.
May
28
revised ST_Distance is not delivering right results
Fix coordinates.
May
28
revised ST_Distance is not delivering right results
added 137 characters in body
May
28
comment ST_Distance is not delivering right results
I believe WKT requires POINT coordinates to be specified in the order longitude, latitude, so you have them the wrong way around.
May
28
answered ST_Distance is not delivering right results
Feb
9
awarded  Tumbleweed
Jan
17
comment Calculating a spherical polygon centroid
I found it, and realised you translated it to English, so thank you. :)
Jan
10
comment Calculating a spherical polygon centroid
Do you mind providing a reference for the area calculation due to Bessel, too? I can't seem to find it anywhere, and I'm interested in writing a fast (and accurate) spherical polygon area routine. Thanks!
Jan
4
comment How to create an accurate Tissot Indicatrix?
How did you compute the orientation of the ellipses?
Dec
28
comment Calculating a spherical polygon centroid
Great, thanks for the reference.
Dec
27
comment Centroid of the equator and a point
I changed "bottommost" to "southernmost" for clarity. I'm trying to describe how I'm generalising the planar center of mass to a sphere. Do let me know if my intuition is incorrect here!
Dec
27
revised Centroid of the equator and a point
s/bottommost/southernmost