[Proj] Snyder ISEA

[Paul B. Anderson]

- Hi All,

While I've been a list member for a couple of years, I've never posted 
anything until now. This seems to be as good a time as any to let everyone 
on the list know that John P. Snyder gave me a copy of his personal software 
about a month before his passing. If anyone WANTS a copy, contact me off 
list and I will give you the URL where you can download it. I will also send 
you some operational notes. John wrote his program in MSDOS GWBasic/Quick 
Basic 4.5, and what I have is fully functional. Check the 'Miscellaneous 
Section' of my web site for graphics of Snyder's projections that I made 
using his program:

http://www.ilstu.edu/microcam/map_projections/index.html

Paul B. Anderson FCCS (USN, Retired)
Kingsport, TN native living in Norfolk, VA

----- Original Message ----- 
From: "Lili Zhang" <zhangli at supermap.com>
To: "PROJ.4 and general Projections D" <proj at lists.maptools.org>
Sent: Wednesday, October 19, 2005 7:57 AM
Subject: Re: Re: [Proj] Snyder ISEA


> Strebe,
>    Many thanks for your reply.
>
> The acronym ISEA stands for icosahedral Snyder equal area.
>
>    I got to know ISEA at the website: 
> http://www.sou.edu/cs/sahr/dgg/isea/isea.html
>
>    I am doing some work on hierarchical spatial partitioning method on the 
> ellipsoid suface with equal erea.
>
>    So ,the paper An equal-area map projection for polyhedral globes maybe 
> is very important for me.
>
>    Is there any resource code that implemented Snyder's equal-area map 
> projection ?
>
> ======= 2005-10-18 23:46:25£º=======
>
>>Snyder described at least three methods for creating customizable 
>>equal-area
>>projections, as well as an equal-area projection for arbitrary polyhedral
>>faces. I'm not aware of any of them called "ISEA".
>>
>>See:
>>
>>"Optimizing equal-area map projections using least squares", American
>>Congress on Surveying and Mapping, Reno, ASPRS-ACSM 1987 Fall Convention, 
>>ACSM
>>Technical Papers, p. 5-13.
>>
>>"An equal-area map projection for polyhedral globes," Cartographica, Vol. 
>>29,
>>No. 1, Spring 1992, pp. 10-21.
>>
>>"New equal-area map projections for noncircular regions," The American
>>Cartographer, Vol. 15, No. 4, October 1988, pp. 341-355.
>>
>>"Minimum-error equal-area map projections," (with John A. Dyer), The 
>>American
>>Cartographer, Vol. 16, No. 1, 1989, pp. 39-43.
>>
>>
>>Regards,
>>daan Strebe
>>
>>
>>In a message dated 10/18/05 09:53:13, zhangli at supermap.com writes:
>>
>>> Hi,
>>>    Does someone know?Snyder Equal Area (ISEA) projection?   Or where can 
>>> I
>>> find some information about this projection ?
>>>
>>>    Any suggestions is appreciated.
>>>   
>>>    Thanks.
>>>
>>>
>>>
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>
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> ¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡ÖÂ
> Àñ£¡
>
>
> ¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡Lili Zhang
> ¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡zhangli at supermap.com
> ¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡2005-10-19
>
>
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