Snyder ISEA

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Snyder ISEA

Lili Zhang-2
Hi,
   Does someone know  Snyder Equal Area (ISEA) projection?   Or where can I find some information about this projection ?

   Any suggestions is appreciated.
   
   Thanks.


       

       Best regards
----------------------------------------------------------
        Zhang Lili
        Ph.D Candidate Institute of Geography and Nature Resource Reseach,
        Chinese Academy of Sciences

    NO. 11jia, Datun Road, Chaoyang District, Beijing, 100101, China
    E-Mail: [hidden email]
    Http://www.igsnrr.ac.cn, www.gischina.com
    Voice: +86-10-82736655   Fax: +86-10-82734630
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Re: Snyder ISEA

strebe

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, [hidden email] 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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Re: Re: Snyder ISEA

Lili Zhang-2
In reply to this post by Lili Zhang-2
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:=======

>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, [hidden email] 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.
>>
>>
>>
>_______________________________________________
>Proj mailing list
>[hidden email]
>http://lists.maptools.org/mailman/listinfo/proj

= = = = = = = = = = = = = = = = = = = =
                       

        致
礼!
 
                                 
        Lili Zhang
        [hidden email]
          2005-10-19


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Re: Re: Snyder ISEA

Paul B. Anderson-2
- 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" <[hidden email]>
To: "PROJ.4 and general Projections D" <[hidden email]>
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:=======
>
>>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, [hidden email] 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.
>>>
>>>
>>>
>>_______________________________________________
>>Proj mailing list
>>[hidden email]
>>http://lists.maptools.org/mailman/listinfo/proj
>
> = = = = = = = = = = = = = = = = = = = =
>
>
>         致
> 礼!
>
>
>         Lili Zhang
>         [hidden email]
>           2005-10-19
>
>
> _______________________________________________
> Proj mailing list
> [hidden email]
> http://lists.maptools.org/mailman/listinfo/proj
>
>


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Re: Snyder ISEA

pw-3
Paul B. Anderson wrote:

> - 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:
>


If you'd like the GWBASIC converted to C/C++, or something else
more current, let me know. At very least make lots of backups.

Peter Willis

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Re: Snyder ISEA

Paul B. Anderson-2
- pw,

It was not my intent to hi-jack Lili Zhang's post. Yes, code for Snyder's
ISEA is in the zipped file I mentioned.

I've been giving John's code away since 1997. Gerald Evenden, as far as I
know, is the only person that has done any work with John's software code
and placed it back into the public domain. I'm perfectly happy to maintain
custody of the original. I'm also very happy to give out copies to anyone
that wants it.

- PBA

----- Original Message -----
From: "pw" <[hidden email]>
To: "PROJ.4 and general Projections Discussions" <[hidden email]>
Sent: Wednesday, October 19, 2005 4:22 PM
Subject: Re: [Proj] Snyder ISEA


> Paul B. Anderson wrote:
>> - 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:
>>
>
>
> If you'd like the GWBASIC converted to C/C++, or something else
> more current, let me know. At very least make lots of backups.
>
> Peter Willis
>
> _______________________________________________
> Proj mailing list
> [hidden email]
> http://lists.maptools.org/mailman/listinfo/proj
>
>


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