Re: country borders on 2d-world

[Daniel J S. <dan...@ie...>]

On 10/22/2015 01:47 PM, Juhász Péter wrote:
> On Thu, 2015-10-22 at 00:17 -0500, Daniel J Sebald wrote:
>> On 10/21/2015 07:02 PM, Valerio Schiavoni wrote:
>>> Hello,
>>> it is known that drawing a 2D map of the world is possible:
>>> - http://www.gnuplotting.org/plotting-the-world-revisited/
>>> - http://gnuplot.sourceforge.net/demo/world.html
>>>
>>> But, suppose that I want to:
>>> - also show the country/nation/state borders and
>>> - some of the country/nation/states need to be highlighted somehow (a
>>> different filling color than plain white would be ideal)
>>>
>>> Ideally there would be several groups of country/nation/states sharing
>>> the same filling colours
>>>
>>> Has anyone ever attempted at this ?
>>> Suggestions ?
>>
>> I've thought of doing such a thing:
>>
>> http://sourceforge.net/p/gnuplot/mailman/message/26788631/
>>
>> Although it isn't a type of plot I'd use in my field, it would be a
>> really nice feature given how common this type of geographical "plot"
>> with data points is today.  A command syntax is going to be the
>> difficult part.  Defining the maps is another issue.  What if boundaries
>> change?  Is there some type of universally accepted data format or
>> descriptive language for map boundaries these days?
>>
>> Dan
>>
>
> Two more issues that count against including high-resolution map data
> into gnuplot itself:
>
> - licensing
> - data size
>
> In more detail:
>
> The first link in the OP refers to
> http://www.naturalearthdata.com/downloads/ , where you can eventually
> download datasets for continent, lake and country boundaries in three
> different resolutions. It says that the dataset is in the public domain,
> which means that it's fine if you want to produce maps with it on your
> own, and it may be fine for inclusion into gnuplot (but IANAL).
> The highest resolution dataset that includes country borders is>5 MB
> compressed, which is comparable to the current size of gnuplot's binary
> package.

Well, I would think including the data itself would be out of the 
question.  Having it accessible is the important thing.  But judging the 
contents of that website parts of it seem relevant.  The "cultural" maps 
(i.e., vector outlines of countries) seem most pertinent.  In the zip 
files I see DBF files as the largest component.  The ESRI you pointed 
out below uses DBF.


> There is also GSHHG, http://www.soest.hawaii.edu/pwessel/gshhg/ , which
> is used by software packages such as GMT or IDL, however, its license is
> LGPL, which is not compatible with gnuplot's license - or is it?
> The entire package is above 100 MB which precludes its inclusion (but it
> contains lower resolution datasets that are likely smaller).

Here it looks like the World Vector Shorelines data is most useful.


>> "Is there some type of universally accepted data format or descriptive
>> language for map boundaries these days?"
>
> Universally accepted? I don't think so.
> However, there are many competing, widely recognized formats, ESRI
> Shapefile being perhaps the most used.

I wasn't aware of ESRI; interesting stuff.  Thanks.

It would be a big project, and I still wonder about combining the map 
data with a 1) plot and 2) statistical data in a way that is easy to use.

Dan