Stephen Davies writes:
Thanks for the feedback.
Turning on PostgreSQL logging did indeed reveal more information.
However, it leaves even more confused than before.
It seems that the underlying cause of my results is that the extent
being used by mapscript bears no relation to the extent that I
specified.
Here is the sql statement generated from mapscript:
2006-03-18 16:22:47 CST LOG: 00000: duration: 33.759 ms statement:
DECLARE mycursor BINARY CURSOR FOR SELECT
location::text,asbinary(force_collection(force_2d(geom)),'NDR'),id::text
from probe WHERE geom && setSRID('BOX3D(139.522253226183
-0.000314231148091942,139.522253452601 -0.000314003203767908)'::BOX3D,
find_srid('','probe','geom') )
The actual extent specified (and the one that works from CGI mapserv)
was:
139.5143351 -34.7459112 139.5278707 -34.7207064
The "correct" query as generated by a CGI call with the above mapext is:
2006-03-18 16:11:57 CST LOG: 00000: duration: 33.703 ms statement:
DECLARE mycursor BINARY CURSOR FOR SELECT
location::text,asbinary(force_collection(force_2d
(geom)),'NDR'),id::text from probe WHERE geom &&
setSRID('BOX3D(139.508530404246 -34.7456930137356,139.533675395754
-34.7204885334377)'::BOX3D, find_srid('','probe','geom') )
Again the extent is changed but nowhere as drastically.
I then tried hard-wiring the extent into the map file and removing the
mapext argument from the CGI call and got the same result and the same
query.
I then modified my PERL script to use the extent in the map file and
again got the same result and the same query generated.
It looks as if the mapscript setExtent method does something strange and
different from the CGI mapext option and that both do strange things
with extent statements in map files in some circumstances.
I tried changing the UNITS to DD but this made no difference (METERS is
required to make reference maps etc work properly in the CGI world.)
Stephen,
Did you already try printing the values of $miny & $maxy or run it with
"perl -d"?
If they args read in are correct then I'm wondering if:
my $rect = mapscript::rectObj->new($minx,$miny,$maxx,$maxy);
$map->{extent} = $rect;
would have a different effect.
Lowell
