[R-sig-Geo] How to translate coordinates from cylindrical to a Lambert Azimuthal Equal Area Projection
Ivailo
ubuntero.9161 at gmail.com
Wed Apr 24 12:36:21 CEST 2013
On Wed, Apr 24, 2013 at 12:34 PM, Julian M. Burgos <julian at hafro.is> wrote:
> Hi Ivailo,
>
> I would just create a SpatialPoints object with four points defining the
> horizontal and vertical extent of your area of interest. Something like
> this:
>
> maximum latitude, mean longitude
> minimum latitude, mean longitude
> mean latitude, maximum longitude
> mean latitude, maximum longitude
>
> Make sure that the projection for these points is ("+proj=longlat
> +datum=WGS84").
>
> Then use the spTransform function (rgdal package) to transform these
> four points into the Lambert Azimuthal Equal Area projection. Now you
> have your horizontal and vertical ranges.
>
> Next, use the raster package. Create an Extent object with your
> horizontal and vertical ranges, and use the crop function to change the
> extent of your raster to your area of interest.
>
> Good luck!
>
> Julian
Thank you for the input, Julian! In the previous post Barry worked out
a similar approach to solving the task at hand.
Best,
Ivailo
--
UBUNTU: a person is a person through other persons.
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