Thanks for the help. The red pixel trick allows me to see the point. It is in the center of the plane and it looks like I have about a 10 pixel wingspan for the chosen SIZE 9.
Now my question is about the tolerance. Does "TOLERANCE 5" mean a 5 pixel radius or a 5 pixel diameter? I'm querying with PHP mapscript and expect multiple results in some cases where items are very close together. I'm just seeing some multiples where I do not expect them, but this may be due to the TOLERANCE being set too high. I'm still playing to get a grip on how this works. -----Original Message----- From: Steve Lime [mailto:[email protected]] Sent: Monday, July 06, 2009 11:48 AM To: [email protected]; Worth Lutz Subject: Re: [mapserver-users] point layer symbols Hi Worth: When you define a vector symbol you're essentially defining a default size as well (I believe) relative to 0,0. The SIZE you set is then used to scale the symbol based on that default size. If things are anchored to 0,0 then it generally works ok. I always try to work on the unit square (0,0,1,1) when defining symbols although that's not required. Being relative to 0,0 is important. Anyway, a symbol is always centered on the point. Where the actual point is depends on how you laid out the symbol. To see this try adding another styleObj after your main symbol like so: CLASS NAME "Major Airport" EXPRESSION "MAJOR AIRPORT" STYLE COLOR 139 0 139 SYMBOL 'airplane' SIZE 9 END STYLE # a red pixel COLOR 255 0 0 END ... END You should see a red pixel over your airplane. That may help explain why you see the clicking issues you do. The placement is based on the bounds of the symbol (0,0,maxx, maxy) so if a symbol is defined well away from 0,0 then odd things can happen. We hope to fix this in upcoming releases. If you're having trouble with multiple results why not use mode=query instead of nquery? Steve >>> On 7/5/2009 at 4:56 PM, in message <3684fed92d7a43618e4c56edce0ad...@worthlaptop>, "Worth Lutz" <[email protected]> wrote: > Can anyone help describe how point symbols defined as type vector are placed > upon the point on the map. > > My symbol and layer are listed below. I get a good looking symbols. > > > > My problem occurs when clicking on this symbol (and others like a triangle) > to query it. > > > > If I click at the bottom of the airplane, I often get no results. > > > > If I click above the top of the airplane, I can get results. > > > > Raising the tolerance causes multiple results when the symbols are close > together but not touching. > > > > How is the box surrounding the symbol (the bounds of the symbol) placed upon > the point on the map? And how does size 9 in the class definition relate to > the size of this box? Can anyone shed some light on this for me? > > > > Thanks, > > Worth > > > > SYMBOL > > NAME 'airplane' > > TYPE vector > > POINTS > > 7 0 > > 6 1 > > 6 3 > > 0 4 > > 0 6 > > 6 5 > > 6 8 > > 3 8 > > 3 9 > > 11 9 > > 11 8 > > 8 8 > > 8 5 > > 14 6 > > 14 4 > > 8 3 > > 8 1 > > 7 0 > > END > > FILLED TRUE > > END > > > > LAYER > > NAME "airports" > > STATUS OFF > > TYPE POINT > > DATA "air" > > PROJECTION > > "init=epsg:32119" # NAD 83 North Carolina (meters US) > > END > > MAXSCALEDENOM 3750001 > > TOLERANCE 7 > > CLASSITEM "CLASS" > > LABELITEM "ARPT_NAME" > > CLASS > > NAME "Major Airport" > > EXPRESSION "MAJOR AIRPORT" > > COLOR 139 0 139 > > TEMPLATE 'void' > > SYMBOL 'airplane' > > SIZE 9 > > LABEL > > TYPE TRUETYPE > > MINFEATURESIZE 50 > > MINDISTANCE 150 > > POSITION UC > > FONT vera > > SIZE 7 > > #SIZE SMALL > > COLOR 139 0 139 > > END > > END > > # ** MORE SIMILAR CLASSES HERE *** > > END > > _______________________________________________ mapserver-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapserver-users
