Re: Map Projection with Mathematica
- To: mathgroup at smc.vnet.net
- Subject: [mg40293] Re: Map Projection with Mathematica
- From: Bill Rowe <listuser at earthlink.net>
- Date: Sun, 30 Mar 2003 04:08:35 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
On 3/29/03 at 5:20 AM, thiery.balser at gmx.net (Thiery Balser) wrote:
>I'm wondering whether there's a smart way to do map projections with
>mathematica.
>I know that mathematica comes along with the package `WorldPlot. So is
>there anyway to access the data they're using there? They even got
>some different projections options but the point is that I want to do
>in on my own.
>Has anyone got experience in this?
Have you opened the file WorldPlot.m that comes with Mathematica using a text editor or something else that can display ASCII? If you do this you will find you can review the code used to implement each of the functions. Additionally, there is information regarding the sources used to develop this package.
As far as accessing the data used, the first line of code after the comments is
BeginPackage["Miscellaneous`WorldPlot`","Miscellaneous`WorldNames`",
"Miscellaneous`WorldData`","Utilities`FilterOptions`"]
suggesting the file WorldData.m contains the data of interest. And that file contains the comment
(* :Source:
These data are derived from what was originally a CIA database,
released into the public domain by the Freedom of Information
Act. I acquired a copy of these data, and rearranged them
to the form below. The copy I found was from the Amiga
Fish disks, a public-domain distribution of software for the
Amiga computer, under the name WorldDataBank. Note that these
data (in the original format) are available at higher resolution
from this source.
*)
Looking at the packages that were distributed with Mathematica is a very good way to learn by example many useful techniques.