[mapserver-users] Zooming in to a useful itemquerie point data extent

[Michael Schulz]

Hi Bart,

some days ago, Steve posted this answer:

--snip
Here's what's happening. The query is executing correctly, the problem
lies in buiding a viable extent from
the resulting point. With a single point you end up with a degenerate
extent which tends to screw things
up a bit. There are a couple of solutions.

1) omit the mapext=shapes unless you really need it
2) set CGI parameters buffer or scale so that the MapServer has
something to build the extent from in
addition to selected center point
3) set MINSCALE in the WEB object, I believe the software falls back on
that if the parameters in 2) aren't given
--snip

HTH, Michael


Bart van Heijningen schrieb:

>  Hi all,Problem:I am performing a text query on a point layer, (6
> number zip code layer, dutch format).When you ask the result to be
> displayed using the "mapext=shapes" extention the extention will be
> too small to see anything as we are talking about a point query wint
> one point a s result.Workaround I came up with to get the desired map
> extention:The user performs a query to a 6 number zip code layer (e.g.
> 3527AW) I take off the two last digits (result -> 3572), which
> therefore results in a multiple point query of the area incorporating
> the zip code the user actually wants.Now "mapext=shapes" zooms in
> perfectly to the desired zon, however I now have all zip codes
> incorporating 3572 (from AA to ZZ) om my map where I am only
> interested in the one 3527AW.So how do I use the first extent to be
> the exten of the second query???I already tried numerous of things but
> as of now did not get any further.I also tried someting like
> "map_extent=shapes" ...I call the mapserver qeury as follows<td><img
> src="/cgi-bin/mapserv?map=[map]&item=Pc6nr&value=[value2]&mode=itemquerymap&mapext=shapes"
> height="300" width="300"></td>gives the right extent, but too many
> points.
> <td><img
> src="/cgi-bin/mapserv?map=[map]&item=Pc6nr&value=[value]&mode=itemquerymap&mapext=shapes"
> height="300" width="300"></td>gives the right point but the wrong
> extent of one point (not good)TIA,Bart ing. Bart van HeijningenATsence
> B.V.http://www.atsence.nl

--
-----------------------------------------------------------
Michael Schulz                                in medias res
Dipl.-Geologe                              Gesellschaft für
                                Informationstechnologie mbH
                             Sautierstr. 38, 79104 Freiburg
                                     0761 55695-95 (Fax 96)
mschulz at webgis.de                             www.webgis.de