QueryByPoint in php mapscript - 0 results

[Didrik Pinte]

On Tue, 2007-10-16 at 12:31 -0700, cool frenz wrote:
> Hi,
> I am trying to perform querybypoint but have been unable to get any
> result. 
> The procedure that i am following:
> 1) Get clicked pixel points.
> 2) convert to georef coordinates. (Got them correct)
> 3) Querying the layer with this point.
> 4) Checking for results : Found none
> 
> Code Snippet:
> $mypoint =ms_newPointObj();
>     $mypoint->setXY(17.94031626 , 79.29237528); // To check i directly
> put a point though i tried with clicked point as well
>     $check=@$map->queryByPoint($mypoint,MS_MULTIPLE, 20);
>     $layer1=$map->getlayerbyname("cotton");
>     if( $check == MS_SUCCESS)
>       {
>           $count_results = $layer1->getNumResults();
>         print "NO = ".$count_results." ";
>     }

> Earlier i wasnt using any template then i used a dummy template
> (completely blank) to make it work but still it gave no result.
> 
> Please let me know where i am mistaken ?

Hi Piyush,

Some hints to debug the problem.

Have you tested by querying the layer directly and not the all map ? 

   $layer1 = $map->getlayerbyname("cotton");
   $check  = $layer1->queryByPoint($mypoint,MS_MULTIPLE, 20);

What about the toleranceunits of the layer  ?

    $layer1->set("toleranceunits",MS_METERS);

Remove the @ so that you does not hide errors coming from the queryByPoint method.

Are you sure they are some points under your fake click ?

Here is a link with a working example : http://www.itae.be/gis/querying-dynamic-point-layer-with-php-mapscript.html 


-- 
Didrik <dpinte at itae.be>
Information Technologies for the Agro-Environment
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