Module talk:Location map/data/Canada Alberta

Transverse Mercator conversion

I've been working on updating and creating a lot of Western Canadian cartographic materials, and I think there are a couple things that could be improved with this locator module.

• The vertically exaggerated equirectangular projection causes a lot of distortion, because of Alberta's large extent and high latitude.
• The second-level divisions depicted on the map are census geometries of no administrative relevance.

So, I've created an alternative which minimizes distortion by using the province's standard EPSG:3401 transverse Mercator projection, and depicts the same assortment of counties and municipal districts (which do have administrative relevance) seen on other articles about Alberta local government. In order to test it, I've put a copy at Module:Location map/data/Canada Alberta TM, which was probably the wrong thing to do. The code can be seen below:

return {
	name = 'Alberta',
	x = '50 + 796 * 0.5 * ln( ( 1 + cos($1*(pi/180))*sin(($2+115)*(pi/180)) ) / ( 1 - cos($1*(pi/180))*sin(($2+115)*(pi/180)) ) )',
	y = '516.2 - 489*(atan(tan($1*(pi/180))/cos(($2+115)*(pi/180)))+0)',
	image = 'Alberta County Point Locator.svg'
}

Given the same lat/long pairs used by current Alberta locator calls, it renders as follows:

SW

NW

SE

NE

Fort McMurray

Medicine Hat

Kelowna

If this seems like an improvement, I would appreciate if someone with template privileges could make this change. Thanks!

Awmcphee (talk) 03:47, 7 June 2019 (UTC)

Template-protected edit request on 8 February 2021

Topo map: image1 = 'Canada Alberta relief location map - transverse mercator proj.svg' SANtosito (talk) 15:07, 8 February 2021 (UTC)

 Done Izno (talk) 22:54, 9 February 2021 (UTC)