Chris,
I have actually tested the within function yesterday with 2 shape
files using the latest mapserver and I was getting the results as
expected. If you can provide me with a small data set that I can use to
do some tests, I can look into it.
Later,
CamKhmer wrote:
Hi Yewondwossen,
Thanks for your feedback, as you said districts are within provinces. I
tried switching the statement and running it through an if statement like
so:
if($oDistShape->within($oProvShape)) {
echo "true";
}
else {
echo "false";
}
This just returned false on every attempt as the argument isn't recieving
any value, true or false. I really don't think this is a syntax issue. The
method just won't return a result if the shapes are from serperate shape
files, is this how it is supposed to work or is this an issue with the
Mapscript implimention?
Regards,
Chris
Yewondwossen Assefa wrote:
Chris,
The within function returns true or false so tests should be done like
this if ($oProvShape->within($oDistShape)) echo "1" else echo "0". The
blank page in your case simple means that the within function returned
false.
Is it possible that the test you are doing is inversed? : by looking
at the name of the layers, I am assuming that districts are inside
provinces so a call $oProvShape->within($oDistShape) would return false
and the $oDistShape->within($oProvShape); would return true.
I have checked the documentation of php mapscript and it was stated
incorrectly leading to the confusion. It is now updated and reflects the
correct syntax.
Let me know if that solves your problem.
Best Regards,
CamKhmer wrote:
Hi Steve,
Thanks for your response. I am not receiving the response I was expecting
from the shapeObj->within() method when I pass to it a shapeObj from a
separate layer. I was expecting that GEOS would compare the geometry of
shape A and shape B then determine whether one was within the other, if
this
was the case I thought that this method could take any valid shape object
regardless of its source, but this appears not to be the case. Here's a
thinned down version of what I'm trying to do (apologies for posting an
elongated chunk of code up):
<?php
$oMap = ms_newMapObj($szMapFile);
function getShapeByName($oMap, $sLayerName, $sColumnName, $sShapeName){
$oLayer = $oMap->getLayerByName($sLayerName);
$oLayer->open();
//returns all the shapes in the layer
$status = $oLayer->whichShapes($oMap->extent);
//Loop through each of the shapes
while ($shape = $oLayer->nextShape())
{
$shapeIndex = $shape->index;
$oShape = $oLayer->getShape(-1,$shapeIndex);
$sName = $oShape->values[$sColumnName];
//return if we have the shape we're after
if($sName == $sShapeName) {
return $oShape;
}
}
return null;
//$oLayer->close();
}
//Get the province shape obj
$oProvShape = getShapeByName($oMap, 'provinces_fill',
'NAME','KHAMMUANE');
//Get the district shape obj
$oDistShape = getShapeByName($oMap, 'districts', 'NAME', 'NAKAI');
//This shows I have the shape object so we know there are no problems
prior
to this
print_r($oProvShape);
print_r($oDistShape);
//See if one shape is within another
$inside = $oProvShape->within($oDistShape);
//Should return true or false
echo $inside;
?>
The above code just returns a blank screen, if I replace:
$inside = $oProvShape->within($oDistShape);
with:
$inside = $oProvShape->within($oProvShape);
It returns 1 as expected, which indicated to me that shape objects from
one
shape file can't be passed as an argument for the within() method of a
shape
object from a different shape file. Is this the case? If so is there any
work around you can think of that doesn't involve dumping all the layers
in
a single shape file.
Thanks for any input you can give me.
Chris
Steve Lime wrote:
Chris: The GEOS operators work at the shapeObj level and have no
connection to
parent layers (you can create shapeObj's without mapfiles).
Are you seeing strange behavior?
Steve
CamKhmer <[EMAIL PROTECTED]> 10/24/2006 7:27:14 AM >>>
Hi Guys,
I have just begun experimenting with the GEOS functions now available in
4.10 via mapscript and have a question.
Can shape objects from layer object A be passed as arguments to shape
object
methods in layer object B? (Each layer has a separate shape file)
I am trying to create a function that determines if shape A (district) is
within shape B (province), as stated above both layers are separate
layers
in separate shape files.
I know I have the objects needed as both can be output using print_r(), I
know the method is working as if I pass a shape object from the same
layer
I
get the results as expected.
Is it just the case that shape objects from different layers or shape
files
cant be passed as objects to shapeObj methods? If so it there any
feasible
way around this or am I just going to have to put both districts and
provinces in the same layer and output them through class references?
Thanks for your ideas,
Chris
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--
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Assefa Yewondwossen
Software Analyst
Email: [EMAIL PROTECTED]
http://www.dmsolutions.ca/
Phone: (613) 565-5056 (ext 14)
Fax: (613) 565-0925
----------------------------------------------------------------
--
----------------------------------------------------------------
Assefa Yewondwossen
Software Analyst
Email: [EMAIL PROTECTED]
http://www.dmsolutions.ca/
Phone: (613) 565-5056 (ext 14)
Fax: (613) 565-0925
----------------------------------------------------------------
