PERL/Mapscript postGIS examples?
Stephen Davies
sdc at SDC.COM.AU
Mon Mar 20 20:55:53 EST 2006
Good pick Eric.
I did as you suggested and changed the projection to "latlong" and it
worked - from mapscript and from CGI mapserv.
(The extent is passed in as args in both cases. That's why you don't see
an extent statement in the mapfile.)
The question now has to be why?
I only changed the one line - well replaced two with one.
I then replaced the original PROJ entries in the mapfile and called
setProjection("proj=latlong"); in the PERL and it worked again.
The original eqc projection still works with CGI mapserv.
What is different with mapscript?
Cheers and thanks,
Stephen
On Tuesday 21 March 2006 08:32, Eric Bridger wrote:
> Not sure why this would work in CGI mode.
> shp2img is the best tool for debugging postgis layers. Well, turning
> on postgres logging works as well.
>
> Just a guess but I suspect a projection issue.
>
> Does your postgis data really have an SRID of 4284? You many need to
> change your DATA statement in the postgis layer to something like:
> DATA "the_geom (select * from probe) using unique oid using
> SRID=4284"
>
> The postgis queries below look like they are attempting to use the
> standard SRID of -1 or lat/lon projection.
>
> Also I don't see any EXTENT in your map file. That should throw an
> error.
>
> I would try getting it all to work with no projection (proj=latlong
> or EPGS:4326) first then start messing with the projections.
>
> Eric
>
> On Sat, 2006-03-18 at 01:15, Stephen Davies wrote:
> > 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.)
> >
> > Cheers,
> > Stephen
> >
> > On Friday 17 March 2006 23:42, Simpson wrote:
> > > Stephen,
> > >
> > > You might try checking the Postgresql logs to see if Mapserver is
> > > connecting and requesting data. Turn on statement logging in
> > > Postgresql config to get details of exactly what is being sent.
> > > You can then run the statement from psql to see if it is
> > > returning what you expect.
> > >
> > > Drew.
> > >
> > > -----Original Message-----
> > > From: UMN MapServer Users List
> > > [mailto:MAPSERVER-USERS at LISTS.UMN.EDU]On Behalf Of Stephen Davies
> > > Sent: Friday, March 17, 2006 12:48 AM
> > > To: MAPSERVER-USERS at LISTS.UMN.EDU
> > > Subject: [UMN_MAPSERVER-USERS] PERL/Mapscript postGIS examples?
> > >
> > >
> > > Could somebody please send me or point me at an example of a
> > > PERL/Mapscript script that displays layers populated from a
> > > postGIS database and/or raster layers?
> > > The following PERL/Mapscript and map file generates an image
> > > containing only the copyright layer.
> > > Exactly the same map file with mapserver invoked as CGI generates
> > > all layers.
> > > (In both cases the extent is provided as args.
> > > eg ./genpics q 1 jpg 139.5143351 -34.7459112 139.5278707
> > > -34.7207064)
> > >
> > > Cheers and thanks,
> > > Stephen Davies
> > >
> > > #! /usr/bin/perl
> > > #
> > > # args are UID (for mapfile), pic sequence #, image type
> > > (extension), extent
> > > #
> > > use strict;
> > > #use CGI;
> > > use mapscript;
> > > my $uno = $ARGV[0];
> > > my $seq = $ARGV[1];
> > > my $ext = $ARGV[2];
> > > my $minx = $ARGV[3];
> > > my $miny = $ARGV[4];
> > > my $maxx = $ARGV[5];
> > > my $maxy = $ARGV[6];
> > > #
> > > # if sequence = 1, create/empty directory (ignoring errors)
> > > #
> > > if ($seq == 1){
> > > mkdir("/var/www/html/status_images/$uno",0777);
> > > unlink </var/www/html/status_images/$uno/*>;
> > > }
> > > #
> > > my $mapfile = "/tmp/$uno.map";
> > > my $map = mapscript::mapObj->new($mapfile);
> > > my $i=$map->setExtent($minx,$miny,$maxx,$maxy);
> > > #
> > > #my $img = $map->prepareImage();
> > > my $img = $map->draw();
> > > my $fname = "/var/www/html/status_images/$uno/$seq.$ext";
> > > $img->save($fname);
> > > ===================================================
> > > MAP
> > > NAME perltest
> > >
> > >
> > > PROJECTION
> > > "proj=eqc"
> > > "lon_0=139.521e"
> > > END
> > >
> > > SIZE 600 600
> > > FONTSET "/var/www/html/benparts/fonts.list"
> > > SYMBOLSET "/var/www/html/benparts/symbols"
> > > UNITS METERS
> > > IMAGETYPE jpeg
> > > OUTPUTFORMAT
> > > NAME jpeg
> > > DRIVER "GD/JPEG"
> > > MIMETYPE "image/jpeg"
> > > IMAGEMODE RGB
> > > EXTENSION "jpg"
> > > FORMATOPTION "QUALITY=75"
> > > END
> > > IMAGECOLOR 255 255 255
> > >
> > > WEB
> > > template /var/www/html/benparts/templates/test1.html
> > > imagepath "/var/www/html/tmp/"
> > > imageurl "/tmp/"
> > > END
> > >
> > > LAYER
> > > TYPE RASTER
> > > NAME "bkgrnd"
> > > STATUS DEFAULT
> > > PROJECTION
> > > "init=epsg:28354"
> > > END
> > > DATA "/var/www/html/benparts/rasters/walker.ecw"
> > > # OFFSITE 0 0 0
> > > PROCESSING "DITHER=YES"
> > > END
> > >
> > > LAYER
> > > CONNECTIONTYPE postgis
> > > NAME "probe"
> > > DATA "geom from probe"
> > > CONNECTION "user=scldad dbname=benparts"
> > > STATUS DEFAULT
> > > TYPE POINT
> > > # FILTER "id in (0)"
> > > PROJECTION
> > > "init=epsg:4284"
> > > END
> > > MAXSCALE 5000000
> > > LABELITEM "location"
> > > CLASS
> > > NAME "Probe (Right Click to select)"
> > > STYLE
> > > COLOR 0 214 0
> > > SYMBOL 'circle'
> > > SIZE 7
> > > END
> > > LABEL
> > > MINDISTANCE 15
> > > POSITION CR
> > > SIZE SMALL
> > > COLOR 0 0 0
> > > FORCE TRUE
> > > END
> > > END
> > > END
> > >
> > > LAYER
> > > NAME 'copyright'
> > > TYPE ANNOTATION
> > > STATUS DEFAULT
> > > TRANSFORM FALSE # coordinates are in pixels
> > > FEATURE
> > > POINTS 10 595 END
> > > END
> > > CLASS
> > > LABEL
> > > TYPE TRUETYPE
> > > FONT arial
> > > SIZE 8
> > > COLOR 255 0 0
> > > POSITION CR
> > > END
> > > TEXT 'Photography supplied by MAPLAND, Environment
> > > Information, Dept Environment & Heritage'
> > > END
> > > END
> > > END
> > > --
> > > =================================================================
> > >==== === This email is for the person(s) identified above, and is
> > > confidential to the sender and the person(s). No one else is
> > > authorised to use or disseminate this email or its contents.
> > >
> > > Stephen Davies Consulting Voice:
> > > 08-8177 1595 Adelaide, South Australia.
> > > Fax: 08-8177 0133 Computing & Network solutions.
> > > Mobile:0403 0405 83
> >
> > --
> > ===================================================================
> >===== This email is for the person(s) identified above, and is
> > confidential to the sender and the person(s). No one else is
> > authorised to use or disseminate this email or its contents.
> >
> > Stephen Davies Consulting Voice: 08-8177
> > 1595 Adelaide, South Australia. Fax:
> > 08-8177 0133 Computing & Network solutions.
> > Mobile:0403 0405 83
--
=======================================================================
This email is for the person(s) identified above, and is confidential to
the sender and the person(s). No one else is authorised to use or
disseminate this email or its contents.
Stephen Davies Consulting Voice: 08-8177 1595
Adelaide, South Australia. Fax: 08-8177 0133
Computing & Network solutions. Mobile:0403 0405 83
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