[adegenet-forum] Use of other projected coordinate systems (e.g. Lambert conformal conic) in the sPCA

[Jombart, Thibaut]

Hi there,

the projection system does not matter too much as long as the Euclidean distances between your locations are a decent reflection of the actual distances.

Best
Thibaut
________________________________
From: adegenet-forum-bounces at lists.r-forge.r-project.org [adegenet-forum-bounces at lists.r-forge.r-project.org] on behalf of Cristen Watt [cristenwatt at trentu.ca]
Sent: 29 November 2014 04:37
To: adegenet-forum at lists.r-forge.r-project.org
Subject: [adegenet-forum] Use of other projected coordinate systems (e.g. Lambert conformal conic) in the sPCA

Hello,
I have a question regarding conversion to UTM and the way the sPCA handles spatial data. I have lynx sampling locations from Western Canada and Alaska. I was originally given these locations in the North America Lambert Conformal Conic projection. However, I saw that the sPCA should be done using UTM.

I converted my points to lat/long in ArcMap, then tried using convUL to convert to UTM. However, I am concerned with this method because my coordinates span a wide geographical extent. The convUL conversion is not recommended for more than one zone to the right or left of the central zone. My data span 10 zones (from Western Alaska to Eastern Alberta). I tried using convUL with the most central zone, but the connection network looked quite distorted, and am concerned about the possibility of 'erroneous results' mentioned in the PBSmapping package.

Here is my main question: Since the projection I originally used (North America Lambert Conformal Conic) is already in meters, is it possible to use these coordinates without conversion to UTM? Will the sPCA perform the correct analyses using this projection?

Thank you,
Cristen




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