[UMN_MAPSERVER-USERS] simple tool for conversion

Thu Dec 9 10:50:22 PST 2004

Joseph,

I would like to say that we are trying to help you as best as we can.  But
the projections concepts are not easy to understand and requires many
knowledge that obviously you don't have (no offense).  Many of us has
studied in geographic, cartographic or geomatic domain and learned the
projection concepts in classrooms or read a lot about that.  So as a
"newbie" like you say, I recommend you to take the time to demystify the
projections and underlying concepts and maybe meet a person who can help you
(it's more easy to understand something when somebody can explain it in
front of you, not by e-mail!).

To begin, I recommend you to take a look at these simple tutorials which
will guide you through the concepts of projection systems:

HYPERLINK
"http://www.colorado.edu/geography/gcraft/notes/coordsys/coordsys_f.html"htt
p://www.colorado.edu/geography/gcraft/notes/coordsys/coordsys_f.html

HYPERLINK
"http://www.geo.hunter.cuny.edu/mp/index.html"http://www.geo.hunter.cuny.edu
/mp/index.html

HYPERLINK
"http://www.udel.edu/johnmack/frec480/480lec_projections.html"http://www.ude
l.edu/johnmack/frec480/480lec_projections.html

After, you will be able to better understand the parameters to set in proj
as well as the dynamic and impact of projected and unprojected datas.  These
concepts are the basis of a good understanding of Mapserver.

Hope this will help you to clarify all these concepts!

Skweda O'Bomsawin

-----Message d'origine-----
De : UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU] De la
part de Joseph Norris
Envoyé : 9 décembre 2004 12:12
À : MAPSERVER-USERS at LISTS.UMN.EDU
Objet : Re: [UMN_MAPSERVER-USERS] simple tool for conversion

Ethan,

At the risk of being flamed into non-existence on this subject.  I have
repeatedly modified my map file to include the projection blocks that you
and others in this list have mentioned.  Each change has provided no
results.  I have sent copies of my projection file for the California zip
map and I have received no explanation of what the terms mean. I have tried
to get simple features to work and this has been unsuccessful. 

I am a complete newbie in the use of mapserver and I have approached the
list giving full knowledge of this.  Not seeing any change at all between my
teacher location shapefile and my California zip file,  I began to examine
in detail the shapefile itself - my teacher shapefile. 

I used the utility fGIS a free arcview look-a-like and I began to manually
build a teacher point layer over my California zip map and then dump the
shape file. ( Incidentally I could bring both my California zip file and the
Teacher point file that I built manually up to my mapserver and it displays
perfectly)

After examining my new point shapefile built with fGIS, I found no lat/long
information that was in accord with the lat/long information I have in my
database.  This led me to the conclusion that I had to convert my lat/long
data to x/y coordinates in accord with the California Zip file.  

Again I began to ask on this list about this - the use of proj and
conversion utilities etc.  I even asked about ( in replies to others
inquires ) formulas for conversion. I received replies of learn basic
algebra or something along that line.  This was of no offense to me but it
was not productive.

Many of the discoveries that I have made that have furthered my on
understanding have resulted from serious hacking sessions of writing script
after script trying to find some correlation between the entries of one
shapefile to entries in the other.  

I keep asking questions following the Chinese proverb:  better to ask a
question and look the fool for 5 minutes than not ask and look the fool for
a lifetime.  

The term "newbie" which does not register in my spell-checker should be
taken seriously and in all fairness some of the list  members have take me
as such and been very helpful.  I apologies to any and all if my newbie-ness
has caused any frustration.

#Joseph Norris (Perl - what else is there?/Linux/CGI/Mysql) print @c=map chr
$_+100,(6,17,15,16,-68,-3,10,11,16,4,1,14,-68,12,1,14,8,-68,4,-3,-1,7,1,14,-
68,-26,11,15,1,12,4,-68,-22,11,14,14,5,15,-90);

-----Original Message-----
From: Ethan Alpert [mailto:ealpert at digitalglobe.com]
Sent: Thursday, December 09, 2004 6:27 AM
To: Joseph Norris; MAPSERVER-USERS at LISTS.UMN.EDU
Subject: RE: [UMN_MAPSERVER-USERS] simple tool for conversion

I still don't see why you feel you must reproject your lat/long data.  Look
back at the emails people have sent you. You just need to set a correct
PROJECTION block for each layer and the mapfile and mapserver will take care
of the rest.

-e

   _____  

From: UMN MapServer Users List on behalf of Joseph Norris
Sent: Wed 12/8/2004 4:40 PM
To: MAPSERVER-USERS at LISTS.UMN.EDU
Subject: Re: [UMN_MAPSERVER-USERS] simple tool for conversion

I do the following:

[joseph at spare:]$ proj +units=us-ft +init=nad83:4202 <<EOD
> -119.770623
> 36.830072
> EOD
-7049825.31     -4677803.10
45036164.88     26747054.17

I am not sure what the results are.  Are these x/y coordinates?  And if so -
which set the upper or the lower.

#Joseph Norris (Perl - what else is there?/Linux/CGI/Mysql) print @c=map chr
$_+100,(6,17,15,16,-68,-3,10,11,16,4,1,14,-68,12,1,14,8,-68,4,-3,-1,7,1,14,-
68,-26,11,15,1,12,4,-68,-22,11,14,14,5,15,-90);

-----Original Message-----
From: UMN MapServer Users List [HYPERLINK
"mailto:MAPSERVER-USERS at lists.umn.edu"mailto:MAPSERVER-USERS at lists.umn.edu]O
n
Behalf Of Lawrence, Kevin
Sent: Wednesday, December 08, 2004 7:05 AM
To: MAPSERVER-USERS at lists.umn.edu
Subject: Re: [UMN_MAPSERVER-USERS] simple tool for conversion

proj - the same utility used for on the fly re-projection

one example
echo $lat $long | proj +proj=lcc +lon_0=95w +lat_0=0 +lat_1=49 +lat2=77 -r

project geographic to
lambert conformal
        origin -95 0
        1st parallel 49
        2nd parallel 77

KL

> ----------
> From:         UMN MapServer Users List[SMTP:MAPSERVER-USERS at LISTS.UMN.EDU]
> on behalf of Joseph Norris[SMTP:sirronj at PACBELL.NET]
> Reply To:     Joseph Norris
> Sent:         Wednesday, December 08, 2004 9:58 AM
> To:   MAPSERVER-USERS at LISTS.UMN.EDU
> Subject:      [UMN_MAPSERVER-USERS] simple tool for conversion
>
> Can anyone make a recommendation for unix command line tool that will
> convert lat/long to xy coordinates?
>
> Thanks.
>
> #Joseph Norris (Perl - what else is there?/Linux/CGI/Mysql) print @c=map
> chr
> $_+100,(6,17,15,16,-68,-3,10,11,16,4,1,14,-68,12,1,14,8,-68,4,-3,-1,7,1,14
> ,-
> 68,-26,11,15,1,12,4,-68,-22,11,14,14,5,15,-90);
>

---
Incoming mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.807 / Virus Database: 549 - Release Date: 2004-12-07

---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.807 / Virus Database: 549 - Release Date: 2004-12-07