[Mapserver-users] Tolerance question ..

[Norbert Thieme]

Murilo Lacerda Yoshida schrieb:
>   Hi all,
> 
>   I have two questions now...
> 
>   First one is about the tolerance I set on the map file. This tolerance 
> is like a radium around the user click? Like, if I set the tolerance to 
> 5 pixels, it would be like if the user clicks on a point, I will query 
> everything in a 5 pixel radium, to all directions?
> 
>   Second one is about the querybypoint method. My first attempt to use 
> tolerance on my map was setting it on the querybypoint method, so I put 
> a 5 on the last parameter. But this tolerance was looking like if it was 
> like 5000000000 kilometers…. In every point of the map I clicked I would 
> query something, even if it was very far from my click. Then I tried to 
> put a -1 on the last parameter, and put tolerance 5 on my map file. It 
> worked fine. But now I’m curious why the 5 of the querybypoint is so 
> different from the 5 of the map file…
> 
>   Thanks,
> 
>      Murilo
> 


Sorry I missed an important point:
The tolerance in the mapfile depends on the definition of the 
toleranceunits. If toleranceunits is not set then it is in pixel.
If you use a tolerance in the querybypoint function <= 0 then mapscript 
uses the value set in the mapfile.
In the other case (tolerance > 0) the tolerance in the querybypoint 
function have to be in georeferenced map coordinates.

And yes, I think it is the definition of the radius for a buffer around 
the pointObj where you make a click.

Regards,
Norbert