[Proj] Data Plotted at Wrong Location

Tran, Toan (MCYS) Toan.Tran at ontario.ca
Mon Dec 10 12:29:45 EST 2007

Ed, thank you for your quick reply.
Initially, I have: 
specified in both my top-level MAP and proper layer, with UNITS METERS.
But when the map was draw, all the points are plotted very closed
I suspect that for some reason, the map-server is plotting the data as
meter instead of degree decimal.
The points/data I used from the previous post was for investigation
purpose... to test why the points/data was so closed together.
They are:

Sorry about the confusion.
I will try posting this in the MapServer list
Thank you for the hint.

	-----Original Message-----
	From: proj-bounces at lists.maptools.org
[mailto:proj-bounces at lists.maptools.org] On Behalf Of Ed McNierney
	Sent: December 10, 2007 11:58 AM
	To: PROJ.4 and general Projections Discussions
	Subject: RE: [Proj] Data Plotted at Wrong Location

	Toan -


	This is probably a better question for the MapServer list, but
you're on the wrong path.  Put the 42304 definition back the way it was
- that's correct.


	The EPSG:42304 projection is a Lambert Conformal Conic
projection, and I assume that's what you want to use for your OUTPUT map
image.  Its units are not in decimal degrees, nor can they be.  You have
an INPUT data layer in decimal degrees, and you'd like MapServer to
reproject that data to your output projection.


	Your top-level MAP file needs the PROJECTION definition you
describe below, and then you also need to have an appropriate PROJECTION
block inside the LAYER definition for the layer in decimal degrees.
That tells MapServer that your input and output data are in different
projections, and the data need to be reprojected.


	The correct EPSG definition for your input data in decimal
degrees will depend on what datum those coordinates use.


	-          Ed     


	Ed McNierney

	Chief Mapmaker

	Demand Media / TopoZone.com

	73 Princeton Street, Suite 305

	North Chelmsford, MA  01863

	ed at topozone.com <mailto:ed at topozone.com> 

	Phone: +1 (978) 251-4242

	Fax: +1 (978) 251-1396


	From: proj-bounces at lists.maptools.org
[mailto:proj-bounces at lists.maptools.org] On Behalf Of Tran, Toan (MCYS)
	Sent: Monday, December 10, 2007 11:32 AM
	To: proj at lists.maptools.org
	Subject: [Proj] Data Plotted at Wrong Location



	I wish to plot several points in Canada, but the problem is that
the points are plotted at the wrong location. My data are in decimal
degree stored in a CSV file. I am guessing that Map Server plots the
points  in meters instead of degree.

	I used this in my map layer: 

	I added this for epsg: 
	<42304> +proj=lcc +lat_1=49 +lat_2=77 +lat_0=49 +lon_0=-95
+x_0=0 +y_0=0 +ellps=GRS80 +datum=NAD83 +units=m +no_defs  no_defs <>

	I try changing: 
	 - <42304> +proj=lcc +lat_1=49 +lat_2=77 +lat_0=49 +lon_0=-95
+x_0=0 +y_0=0 +ellps=GRS80 +datum=NAD83 +units=dd +no_defs  no_defs <>
.... this causes a msProcessProjection(): Projection library error.
unknown unit conversion id error

	 - UNITS METERS to UNITS DD in my map file, but that doesn't

	Sample DATA: 


	Any help is much appreciated 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.maptools.org/pipermail/proj/attachments/20071210/900dc5c6/attachment.html

More information about the Proj mailing list