Tiago, if you're not familiar with geographic projections: 

    1. look at the wikipedia article, 
    2. check out (from the library) a geography textbook, and 
    3. try out the examples at the end of the helpfile for spTransform-methods {rgdal} - add plenty of plot() commands to see what's going on! 

Lee De Cola, PhD, MCP. 
DATA to Insight 
LDECOLA@COMCAST.NET 
Reston, Virginia USA 
703 709 6972 
571 315 0577 mobile 
----- Original Message -----
From: "Tiago Marques" <tiagoandremarques@gmail.com> 
To: r-sig-geo@r-project.org 
Sent: Monday, February 17, 2014 8:09:58 AM 
Subject: [R-sig-Geo] projecting data from decimal degrees to meters 

Dear List, 

Sorry if this is a very basic question, I've searched around and could 
not find a simple answer to it. I am familiar with R, but not with 
geo/GIS stuff. I have a matrix zs containing 3 columns, longitude, 
latitude and depth. Depth is available at a regular grid of points 
covering approximately 200 by 200 km in the Bahamas. The first few lines 
of the data are below: 

head(zs) 
lat long z 
1 23.2383 -78.3133 4.01 
2 23.2383 -78.3100 4.00 
3 23.2383 -78.3066 4.00 
4 23.2383 -78.3033 4.00 
5 23.2383 -78.3000 4.00 

I would like to implement some animal movement simulations, and my 
movement model is parametrized in terms of displacement, in meters. How 
can I project zs to a matrix containing say x,y,z in which the x,y are 
in meters. 

Best, and many thanks in advance for any advice coming this way. 

Tiago 

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