[mapserver-users] Shapefiles - different formats?

Ed McNierney ed at topozone.com
Fri Oct 12 15:21:52 EDT 2001


Interesting - are you suggesting that 8.1 requires a .prj file in a
format that, while perfectly standard, is different from the 3.1 .prj
format?  That would be rather confusing for users, no?

The .prj file you describe is the equivalent of this file:

proj=utm
zone=10
units=m
ellps=GRS80

and you might try (just as an experiment) replacing your current 8.1
.prj file with those lines - it's possible 8.1 reads them in both
formats.

Since I'm *not* an 8.1 user, I'm mostly shooting in the dark here, so if
there are wiser eyes on the list, please jump in!

	- Ed

Ed McNierney
Chief Mapmaker
TopoZone.com
ed at topozone.com
(978) 251-4242


-----Original Message-----
From: Janet Ciavarelli [mailto:Jciavarelli at city.kamloops.bc.ca]
Sent: Friday, October 12, 2001 2:13 PM
To: imap at chesapeake.net; mapserver-users at lists.gis.umn.edu; Ed McNierney
Subject: RE: [mapserver-users] Shapefiles - different formats?


Hi Ed, 
  I think you're thinking of an ArcInfo .prj file format. The .prj file
I attached to a previous message does not have the format you listed,
but rather looks like this:

PROJCS["NAD_1983_UTM_Zone_10N",GEOGCS["GCS_North_American_1983",DATUM["D
_North_American_1983",SPHEROID["GRS_1980",6378137,298.257222101]],PRIMEM
["Greenwich",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Transve
rse_Mercator"],PARAMETER["False_Easting",500000],PARAMETER["False_Northi
ng",0],PARAMETER["Central_Meridian",-123],PARAMETER["Scale_Factor",0.999
6],PARAMETER["Latitude_Of_Origin",0],UNIT["Meter",1]]

Just thought I'd point this out. 

Janet.

Janet Ciavarelli
GIS Programmer/Analyst
City of Kamloops, BC
(250) 828-3393
jciavarelli at city.kamloops.bc.ca

>>> "Ed McNierney" <ed at topozone.com> 10/05/01 09:58am >>>
Janet et al. -

Janet seems to have found the problem.  It appears that ArcGIS 8.1
*requires* a .prj file (which describes the shapefile's projection, not
an ArcView project), which (all else being equal) is a pretty good
thing.  ArcView 3.2 does not require .prj files.

PRJ files are simple text files that probably look familiar to PROJ
users - here's the contents of a simple one.

proj=utm
zone=15
units=m
ellps=GRS80

	- Ed

Ed McNierney
Chief Mapmaker
TopoZone.com
ed at topozone.com 
(978) 251-4242


-----Original Message-----
From: imap at chesapeake.net [mailto:imap at chesapeake.net] 
Sent: Friday, October 05, 2001 12:54 PM
To: mapserver-users at lists.gis.umn.edu 
Cc: Janet Ciavarelli; Ed McNierney
Subject: Re: [mapserver-users] Shapefiles - different formats?



ArcView will read the 3 files just fine.  You have to create
or Open a New Project, then Add Layer, then browse to the
dir where your shapefiles are, then pick one.

A somewhat related comment, There are actually a other 
files that sometimes accompany a shapefile. 

.shp, .shx, .dbf  (main 3 files)
.sbn, .ixs, .mxs  (???  mystery files)
.prj, .apr        (project files I think)

I think the .ixs and .mxs are geocoding indexes 
and .sbn??? who knows.   I'd really like to know
the layout of these other files.  I am not sure
if they come from ArcInfo, or what?  I see a few
3rd party companies create these files within their
ArcView Format, but it may be a proprietary aspect
of Arc???  If anyone has info, please reply an email.

Anyway, The .apr(.prj?) are in ascii and is a long
list of name/value pairs, so a script should be able
to generate/manipulate OK.

Regards,

Chris Stuber (mapsurfer)
Silicon Mapping Solutions, Inc
(410)257-3187




Janet Ciavarelli wrote:
> 
> Hi Ed,
>    I see what the difference is now. I went into ArcCatalog and
created an empty shapefile, and I looked in explorer. It creates 4
files! Not just the 3 files that it used to use (.shp, .shx, .dbf).
> 
> I've attached all the four files. So that explains why ArcView 3.2 can
open the file though. Cause it finds the 3 files and just ignores the
4th. But ArcMap 8 wants all 4 files. The 4th file is a .prj file. I will
have to find out what's in it and get my script to create that as well.
Also, maybe that utility you advised me to grab will create it. I will
check when I get time which my be a long time from now.
> 
> Thanx for your help. Janet.
> 
> >>> "Ed McNierney" <ed at topozone.com> 10/04/01 05:49pm >>>
> Janet -
> 
> Can you create an empty point shapefile in 8.1 and send that to me,
too?
> I don't have 8.1, but I can take a look at the shapefile to see if
> there's anything different.
> 
>         - Ed
> 
> -----Original Message-----
> From: Janet Ciavarelli [mailto:Jciavarelli at city.kamloops.bc.ca] 
> Sent: Thursday, October 04, 2001 4:11 PM
> To: Ed McNierney
> Subject: RE: [mapserver-users] Shapefiles - different formats?
> 
> Yes, same symptom even with records added.
> 
> >>> "Ed McNierney" <ed at topozone.com> 10/04/01 01:10pm >>>
> Janet -
> 
> Do you get the same symptom when you add records to the shapefile?
> 
>         - Ed
> 
> -----Original Message-----
> From: Janet Ciavarelli [mailto:Jciavarelli at city.kamloops.bc.ca] 
> Sent: Thursday, October 04, 2001 4:03 PM
> To: Ed McNierney
> Subject: RE: [mapserver-users] Shapefiles - different formats?
> 
> Hi Ed,
>    Here's a copy of the shapefile. BTW, it is an empty one but it
should
> be successfully able to open empty shapefiles as well. We've tried it
> with both empty and un-empty ones and get the same results: it opens
> find in AV 3.2 but errors out in AV 8.1
> 
> Janet.
> 
> Janet Ciavarelli
> GIS Programmer/Analyst
> City of Kamloops, BC
> (250) 828-3393
> jciavarelli at city.kamloops.bc.ca 
> 
> >>> "Ed McNierney" <ed at topozone.com> 10/04/01 12:38pm >>>
> Janet -
> 
> I certainly expect 8.1 reads 3.2 shapefiles (at least, in general).
> Perhaps it's more likely that you're creating a slightly out-of-spec
> shapefile that's being tolerated by 3.2, but 8.1 is being fussier
about.
> 
> There's a tool called shpfix in the GDAL distribution that might
> possibly help clean up the file.  If you'd like to email me the
> shapefile I'll take a look at it.
> 
>         - Ed
> 
> Ed McNierney
> Chief Mapmaker
> TopoZone.com
> ed at topozone.com 
> (978) 251-4242
> 
> -----Original Message-----
> From: Janet Ciavarelli [mailto:Jciavarelli at city.kamloops.bc.ca] 
> Sent: Thursday, October 04, 2001 2:17 PM
> To: mapserver-users at lists.gis.umn.edu; teb at mallit.fr.umn.edu 
> Subject: [mapserver-users] Shapefiles - different formats?
> 
> Sort of off topic, but thought I'd ask anyways in case anyone knows. I
> have written a perl/mapscript to create a shapefile. I can view the
> shapefile in ESRI  ArcView 3.2 fine. But when I try to view it in ESRI
> ArcView 8.1, I get an error. Is anyone out there aware of any
> differences between shapefile formats between different products?
> 
> Janet.
> 
> 
> 
> Janet Ciavarelli
> GIS Programmer/Analyst
> City of Kamloops, BC
> (250) 828-3393
> jciavarelli at city.kamloops.bc.ca 
> 
>
------------------------------------------------------------------------
--------
>                      Name: shapev8.dbf
>    shapev8.dbf       Type: unspecified type (application/octet-stream)
>                  Encoding: base64
>               Description: dBase 3 database
> 
>    shapev8.prjName: shapev8.prj
>               Type: Plain Text (text/plain)
> 
>                   Name: shapev8.shp
>    shapev8.shp    Type: ESRI Shapefile
(application/x-unknown-content-type-shpfile)
>               Encoding: base64
> 
>                   Name: shapev8.shx
>    shapev8.shx    Type: unspecified type (application/octet-stream)
>               Encoding: base64



More information about the mapserver-users mailing list