[R-sig-Geo] World map in magnetic coordinates

[Barry Rowlingson]

On Fri, Oct 8, 2010 at 5:32 PM, ogbos okike <ogbos.okike at gmail.com> wrote:

> My data points are given in latitude and longitude (geographic). Using AACGM
> geomagnetic coordinate software, I converted them to magnetic coordinates.
> World map (such as implemented in R, which can be generated using maps has
> no data points). It is only implemented in R such that one can use maps
> library to generate it. However, that is in geographic coordinates.

 I'm not sure what world map you are referring to here. Can you tell
us the R commands that plot it?

 The data points are in there somewhere, and if you want to transform
them with something that isn't spTransform then we'll have to tell you
how to get them. If the map is a SpatialPolygonsDataFrame then the
coordinates are obtained by getting the individual polygons which are
made up of rings which are made up of points and so on. Messy but
possible to apply a generic transformation function to them.

 What does your conversion software work on? Text files?

Barry