Yes, but there is a more simple way. Show a part of the table in a mapper,
select the map, options menu, select the projection you want to use and now
your centroidX and centroidY is in that projection.
Ole Gregor, Viborg Amt (County), Denmark
[EMAIL PROTECTED] TLF. (+45) 87271307
> -----Original Message-----
> From: [EMAIL PROTECTED] [SMTP:[EMAIL PROTECTED]]
> Sent: Tuesday, June 08, 1999 12:22 PM
> To: [EMAIL PROTECTED]
> Subject: MI My centroids problem solved!
>
>
>
> From: Chris Skelly@MOH on 08/06/99 22:21
>
>
> To: [EMAIL PROTECTED]
> cc:
> Subject: My centroids problem solved!
>
>
> Thanks to all for their suggestions regarding a problem in MapInfo which
> makes
> it difficult to extract the centroids of polygons in anything but
> Lat-Long, even
> when you are using a cartesian coordinate system. Chris Perry and Jacques
> Paris
> provided a solution that works, which I'll relay here for anyone who is
> interested.
>
> If you run an SQL query using the functions CentroidX(obj) and
> CentroidY(obj) to
> create coordinates from which to create a new points data set, you may
> find (as
> I did) that MapInfo will refuse to give you anything other than Lat-Long
> coordinates. However, if you issue the command "Set coordsys table
> <yourtablename>" in the MapBasic window before the SQL query, MapInfo will
> return the coordinates in the appropriate coordinate system.
>
> A couple of other respondents replied that I could use the Lat-Long
> coordinates,
> save them to a file with a new projection. This works, except for those of
> us in
> New Zealand who still have to deal with the continuing problem that we
> cannot
> save to a NZ Map Grid Coordinate System! It is necessary to paste the
> appropriate coordinate system code into the file (which needs to be
> converted
> into a MIF file first - what a pain!). The line of code is
>
> CoordSys Earth Projection 18, 31, "m", 173, -41, 2510000, 6023150 Bounds
> (1000000, 3000000) (3000000, 8000000)
>
> So thanks guys - my time to a solution from sending in the email - 22
> minutes!
>
> Cheers,
> Chris
>
>
>
> Chris Skelly, PhD, Senior Advisor (Environmental Health),
>
> Public Health Group, Safety and Regulation Branch, Ministry of Health
>
> 133 Molesworth Street, PO Box 5013, Wellington, New Zealand
>
> Ph: +64 4 496-2215, Fx: +64 4 496-2340, Email: [EMAIL PROTECTED],
> WWW:
> http://www.moh.govt.nz
>
>
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