mapscript API shapfileObj units

[Kralidis,Tom [Burlington]]

Correct, there is a .prj file.

Would it be valuable for the mapscript API to add shapefileObj->{units},
which would return as per
http://mapserver.gis.umn.edu/docs/reference/mapscript/index_html#map-uni
ts, else -1 if no .prj is associated?

..Tom
 

> -----Original Message-----
> From: Steve Lime [mailto:Steve.Lime at dnr.state.mn.us] 
> Sent: 30 October, 2006 1:27 PM
> To: Kralidis,Tom [Burlington]; MAPSERVER-USERS at lists.umn.edu
> Subject: Re: [UMN_MAPSERVER-USERS] mapscript API shapfileObj units
> 
> There must be a .prj file accompanying the shapefile? 
> MapScript has no way to get at that although a script could 
> certainly copy that file to the name of the output file for 
> consistency.
> 
> Steve
> 
> >>> "Kralidis,Tom [Burlington]" <Tom.Kralidis at EC.GC.CA> 10/30/2006
> 12:17:58 PM >>>
> Thanks for the info.
> 
> Having said this, if I do an ogrinfo, for example, on a 
> shapefile, I do get some units info returned, i.e.:
> 
> $ ogrinfo -al -summary
> ~tkralidi/geos/data/Confederation_Trail_2005.shp
> INFO: Open of `/home/tkralidi/geos/data/Confederation_Trail_2005.shp'
> using driver `ESRI Shapefile' successful.
> 
> Layer name: Confederation_Trail_2005
> Geometry: Line String
> Feature Count: 601
> Extent: (305059.000053, 657304.420162) - (471874.599925,
> 767349.092887)
> Layer SRS WKT:
> PROJCS["PEI NAD83",
>     GEOGCS["GCS_North_American_1983_CSRS98",
>         DATUM["NAD83_Canadian_Spatial_Reference_System",
>             SPHEROID["GRS_1980",6378137.0,298.257222101]],
>         PRIMEM["Greenwich",0.0],
>         UNIT["Degree",0.0174532925199433]],
>     PROJECTION["Double_Stereographic"],
>     PARAMETER["False_Easting",400000.0],
>     PARAMETER["False_Northing",800000.0],
>     PARAMETER["Central_Meridian",-63.0],
>     PARAMETER["Scale_Factor",0.999912],
>     PARAMETER["Latitude_Of_Origin",47.25],
>     UNIT["Meter",1.0]]
> NAME: String (12.0)
> INDEX: String (12.0)
> </snip>
> 
> ...so I initially imagine that this could be marshalled into 
> shapefileObj.
> 
> ..Tom
> 
>  
> 
> > -----Original Message-----
> > From: Stephen Woodbridge [mailto:woodbri at swoodbridge.com]
> > Sent: 30 October, 2006 1:14 PM
> > To: Kralidis,Tom [Burlington]
> > Cc: MAPSERVER-USERS at LISTS.UMN.EDU
> > Subject: Re: [UMN_MAPSERVER-USERS] mapscript API shapfileObj units
> > 
> > You can't! This is because it is not encoded in the 
> shapefile to start 
> > with. The only reason you can get it from the Layer pbject 
> is because 
> > you can set it in the mapfile and then retrieve it layer into 
> > mapscript.
> > The equivalent behavior would be to create a metadata file for each 
> > shapefile and fetch it from that.
> > 
> > -Steve
> > 
> > Kralidis,Tom [Burlington] wrote:
> > > Hi,
> > > 
> > > We have a script which utilizes the new mapscript geos
> > functionality
> > > by applying a buffer to each shapeObj within a shapefileObj
> > to output
> > > a new dataset.
> > > 
> > > My question is I would like to know the units of shapefileObj (or 
> > > shapeObj).
> > > 
> > > The mapscript API has layerObj->{units} as a property, 
> but I am not
> 
> > > working within the layerObj context (i.e. I am not working on 
> > > mapfiles, just datasets).
> > > 
> > > Any idea on how to fetch this info from the mapscript API without 
> > > layerObj?  I've skimmed through 
> > > 
> http://mapserver.gis.umn.edu/docs/reference/mapscript/index_html as
> 
> > > part of my investigation, but didn't find anything else (or
> > course I
> > > may have glossed over something -- happens to me often!).
> > > 
> > > Thanks
> > > 
> > > ..Tom
> > 
> > 
>