[mapguide-users] can anyone solved this buffer problem
Kenneth Skovhede, GEOGRAF A/S
ks at geograf.dk
Thu Apr 30 07:15:06 EDT 2009
It looks correct, it seems to follow the edges as expected.
When creating the buffer, a simple method is to take each line, and
buffer it,
so it gets rounded corners.
Then alle the resulting buffer items are combined into a single object
that is the buffer.
If I look at your image, that seems to happen correctly.
The long side at the bottom right seems to be reflected in the buffer edge.
If you would like it to be a perfect circle, you should only buffer a point,
not a polygon.
Regards, Kenneth Skovhede, GEOGRAF A/S
padmini godavarthi skrev:
> Hi Kenneth,
>
> i have created a buffer with 0.2 miles but i think the buffer is not
> creating accurately
>
> http://n2.nabble.com/file/n2745746/buffer.jpeg
>
> 1) can u provide any solution?????????????
>
> 2)And can u plz tell me the code for retrieving parcel_id with in the buffer
> area(im a little bit confused)
>
> plzzzzzzzz
>
> Regards,
> Padmini.
>
>
> Kenneth Skovhede, GEOGRAF A/S wrote:
>
>> It looks correct to me. Try using a smaller buffer to better determine
>> accuracy.
>>
>> For the second question, you have already asked that in another thread.
>> The AJAX viewer shows selection data, so try looking at the
>> selection.aspx files,
>> and see how it works.
>>
>> Regards, Kenneth Skovhede, GEOGRAF A/S
>>
>>
>>
>> padmini godavarthi skrev:
>>
>>> Hi Kenneth,
>>> Thanku very much for ur help.............
>>> i did the coordinate system override as per ur instructions.
>>> It works fine
>>> but i felt that the buffer feature is not coming accurately??
>>> what was the problem????????????????????????????
>>>
>>> i mean by observing closely its not an accurate circle(buffer layer).
>>>
>>> http://n2.nabble.com/file/n2683455/pic.jpeg
>>>
>>> 2)secondly i want to retrieve the parcel_ids that are included or
>>> intersected in the buffer layer.How is it possible ? can u send me the
>>> sample code?????????
>>>
>>> Thanks in advance.
>>>
>>> Regards,
>>> Padmini.
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> Kenneth Skovhede, GEOGRAF A/S wrote:
>>>
>>>
>>>> Thats because the Sheboygan data uses a true georeferenced coordinate
>>>> system,
>>>> and your data is using a non-georeferenced system, like XY-M.
>>>> Arbitrary should be understood as "non-georeferenced".
>>>>
>>>> If your data is not in the same projection as the map, you cannot use
>>>> the buffer feature.
>>>>
>>>> This then returns to my initial statement: "Coordinate System Override",
>>>> which can
>>>> set the data coordinate system to match the maps.
>>>>
>>>> Can you please report what happened with with the suggestions I made,
>>>> regarding the coordinate system overrides?
>>>>
>>>> Regards, Kenneth Skovhede, GEOGRAF A/S
>>>>
>>>>
>>>>
>>>> padmini godavarthi skrev:
>>>>
>>>>
>>>>> Hi,
>>>>>
>>>>> In my data
>>>>>
>>>>> bool arbitraryMapSrs = (srsMap.GetType() ==
>>>>> MgCoordinateSystemType.Arbitrary);
>>>>>
>>>>> arbitraryMapSrs comes as true but in sheboygan data it comes as false
>>>>>
>>>>> if (arbitraryMapSrs)
>>>>> mapSrsUnits = srsMap.GetUnits();
>>>>> In mydata mapSrsUnits comes as "meter" but in sheboygan data it comes
>>>>> as
>>>>> null
>>>>>
>>>>> so that
>>>>> if ((arbitraryDsSrs != arbitraryMapSrs) || (arbitraryDsSrs &&
>>>>> (dsSrsUnits
>>>>> != mapSrsUnits)))
>>>>> {
>>>>> excludedLayers++;
>>>>> continue;
>>>>> }
>>>>> In my data excludedLayers comes as 1 and where as in sheboyan data
>>>>> this
>>>>> condition fails....................
>>>>> Can u plz provide me the solution?????????????
>>>>>
>>>>> Regards,
>>>>> Padmini.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> Kenneth Skovhede, GEOGRAF A/S wrote:
>>>>>
>>>>>
>>>>>
>>>>>> Why do you mention packages?
>>>>>>
>>>>>> excludedLayers is incremented because the data coordinate system is
>>>>>> not
>>>>>> the same as the map coodinate system.
>>>>>>
>>>>>> Please comment on what happend when you attempted my previous
>>>>>> suggestions.
>>>>>>
>>>>>> Regards, Kenneth Skovhede, GEOGRAF A/S
>>>>>>
>>>>>>
>>>>>>
>>>>>> padmini godavarthi skrev:
>>>>>>
>>>>>>
>>>>>>
>>>>>>> Hi Kenneth,
>>>>>>> Thanks for ur suggestions.
>>>>>>> I have created a package using OGR provider but in the buffering i
>>>>>>> found
>>>>>>> some problem that
>>>>>>>
>>>>>>> // exclude layer if:
>>>>>>> // the map is non-arbitrary and the layer is arbitrary
>>>>>>> or
>>>>>>> vice-versa
>>>>>>> // or
>>>>>>> // layer and map are both arbitrary but have different
>>>>>>> units
>>>>>>> //
>>>>>>> if ((arbitraryDsSrs != arbitraryMapSrs) ||
>>>>>>> (arbitraryDsSrs
>>>>>>> &&
>>>>>>> (dsSrsUnits != mapSrsUnits)))
>>>>>>> {
>>>>>>> excludedLayers++;
>>>>>>> continue;
>>>>>>> }
>>>>>>> it gives difference to my data and sheboygan sample data
>>>>>>> so that in my code excludedLayers is incremented to 1 so i didnt get
>>>>>>> the
>>>>>>> buffer features
>>>>>>> can u plz tell me the solution?????????????????
>>>>>>>
>>>>>>>
>>>>>>> Regards,
>>>>>>> Padmini.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Kenneth Skovhede, GEOGRAF A/S wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>> I'm not sure that provider is case insensitive.
>>>>>>>> Try adding the file again, but with the name "PROPERTIES.shp".
>>>>>>>>
>>>>>>>> Also, try creating a folder, and place the files in the folder.
>>>>>>>> Then try to use the "External files" and point to the folder.
>>>>>>>> Also try pointing directly to the file.
>>>>>>>>
>>>>>>>> When the "Test connection" is successfull, try clicking the
>>>>>>>> rightmost button in the "coordinate system override" field, and
>>>>>>>> it will show you what the provider returns as the coordinate system.
>>>>>>>>
>>>>>>>> Alternatively, try using the OGR provider instead of the SHP
>>>>>>>> provider.
>>>>>>>>
>>>>>>>> Regards, Kenneth Skovhede, GEOGRAF A/S
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> padmini godavarthi skrev:
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>> Hi Keneneth,
>>>>>>>>> First of all thanks for ur patience
>>>>>>>>> i have uploaded all the files but i didnt get the coordinate system
>>>>>>>>>
>>>>>>>>> http://n2.nabble.com/file/n2676400/file.jpeg
>>>>>>>>>
>>>>>>>>> again i did anything wrong??????????
>>>>>>>>>
>>>>>>>>> Regards,
>>>>>>>>> Padmini.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Kenneth Skovhede, GEOGRAF A/S wrote:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>> IIRC Shape files consist of more than just the SHP file.
>>>>>>>>>> You must upload all the "Properties.*" files to the datasource,
>>>>>>>>>> even if the upload file dialog is misleading (you must select "All
>>>>>>>>>> files" to see them).
>>>>>>>>>>
>>>>>>>>>> A ticket for this problem is here.
>>>>>>>>>> http://trac.osgeo.org/mapguide/ticket/783
>>>>>>>>>>
>>>>>>>>>> Regards, Kenneth Skovhede, GEOGRAF A/S
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> padmini godavarthi skrev:
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>> Hi,
>>>>>>>>>>> but i did it as per ur instruction but it didn't come
>>>>>>>>>>>
>>>>>>>>>>> http://n2.nabble.com/file/n2676097/over.jpeg
>>>>>>>>>>>
>>>>>>>>>>> my code as same as previous
>>>>>>>>>>> MgResourceIdentifier featSourceId = new
>>>>>>>>>>> MgResourceIdentifier(selLayer.GetFeatureSourceId());
>>>>>>>>>>> MgSpatialContextReader ctxs =
>>>>>>>>>>> featureSrvc.GetSpatialContexts(featSourceId, false);
>>>>>>>>>>> String srsDefDs = "";
>>>>>>>>>>> if (ctxs != null && ctxs.ReadNext())
>>>>>>>>>>> srsDefDs = ctxs.GetCoordinateSystemWkt();
>>>>>>>>>>>
>>>>>>>>>>> in srsDefDs i got null
>>>>>>>>>>> does i did any thing wrong
>>>>>>>>>>>
>>>>>>>>>>> Regards,
>>>>>>>>>>> Padmini.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Kenneth Skovhede, GEOGRAF A/S wrote:
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>> Yes, your FeatureSource reports an empty coordinate system, so
>>>>>>>>>>>> you
>>>>>>>>>>>> have
>>>>>>>>>>>> to specify it manually.
>>>>>>>>>>>>
>>>>>>>>>>>> There is a short explanation on how to use overrides here:
>>>>>>>>>>>> http://trac.osgeo.org/fdo/wiki/FdoGdalNotes#OverridingCoordinateSystems
>>>>>>>>>>>>
>>>>>>>>>>>> Regards, Kenneth Skovhede, GEOGRAF A/S
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> padmini godavarthi skrev:
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>> Hi,
>>>>>>>>>>>>> thanks but is it necessary overriding a coordinate
>>>>>>>>>>>>> system????????
>>>>>>>>>>>>> How it willbe done???????
>>>>>>>>>>>>> can u provide me some guidance???????
>>>>>>>>>>>>> i have seen ur link but no data available in that for overrides
>>>>>>>>>>>>> coordinate
>>>>>>>>>>>>> system
>>>>>>>>>>>>>
>>>>>>>>>>>>> http://trac.osgeo.org/mapguide/wiki/maestro/UserGuides/RasterFeatureSource
>>>>>>>>>>>>>
>>>>>>>>>>>>> can u plz tell me????????????
>>>>>>>>>>>>>
>>>>>>>>>>>>> Regards,
>>>>>>>>>>>>> Padmini.
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> Kenneth Skovhede, GEOGRAF A/S wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>> No, I meant "Coordinate System Override", which is located on
>>>>>>>>>>>>>> the
>>>>>>>>>>>>>> FeatureSource editor at the bottom.
>>>>>>>>>>>>>> See screenshots here:
>>>>>>>>>>>>>> http://trac.osgeo.org/mapguide/wiki/maestro/UserGuides/RasterFeatureSource
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Regards, Kenneth Skovhede, GEOGRAF A/S
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> padmini godavarthi skrev:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Hi,
>>>>>>>>>>>>>>> Thanks for ur reply
>>>>>>>>>>>>>>> u man to say in mapdefinition(in maestro)????????????????
>>>>>>>>>>>>>>> iam using maestro and i have selected the coordinate system
>>>>>>>>>>>>>>> as
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> http://n2.nabble.com/file/n2675676/coor.jpeg
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> does i did any thing wrong???????????????
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Regards,
>>>>>>>>>>>>>>> Padmini.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Kenneth Skovhede, GEOGRAF A/S wrote:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Have you tried to add a coordinate system override,
>>>>>>>>>>>>>>>> using Maestro or Studio?
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Regards, Kenneth Skovhede, GEOGRAF A/S
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> padmini godavarthi skrev:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Hi,
>>>>>>>>>>>>>>>>> iam using mapguide opensource 2.0 (with .net 2.0 +IIS 5.1)
>>>>>>>>>>>>>>>>> i want to make a buffer to my data
>>>>>>>>>>>>>>>>> the buffer function works fine for this sheboygan data but
>>>>>>>>>>>>>>>>> not
>>>>>>>>>>>>>>>>> for
>>>>>>>>>>>>>>>>> my
>>>>>>>>>>>>>>>>> data
>>>>>>>>>>>>>>>>> i have debugged the application and i got the error at
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> MgResourceIdentifier featSourceId = new
>>>>>>>>>>>>>>>>> MgResourceIdentifier(selLayer.GetFeatureSourceId());
>>>>>>>>>>>>>>>>> MgSpatialContextReader ctxs =
>>>>>>>>>>>>>>>>> featureSrvc.GetSpatialContexts(featSourceId, false);
>>>>>>>>>>>>>>>>> String srsDefDs = "";
>>>>>>>>>>>>>>>>> if (ctxs != null && ctxs.ReadNext())
>>>>>>>>>>>>>>>>> srsDefDs = ctxs.GetCoordinateSystemWkt();
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> In Sheboygan data
>>>>>>>>>>>>>>>>> srsDefDs comes as GEOGCS["WGS84 Lat/Long's, Degrees, -180
>>>>>>>>>>>>>>>>> ==>
>>>>>>>>>>>>>>>>> +180",DATUM["D_WGS_1984",SPHEROID["World_Geodetic_System_of_1984",6378137,298.257222932867]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> but for my data
>>>>>>>>>>>>>>>>> srsDefDs comes as null
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Actually my data is in coordinate system
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS
>>>>>>>>>>>>>>>>> 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],TOWGS84[0,0,0,0,0,0,0],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.01745329251994328,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]]
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> can u plz tell me the solution????????????????????????
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> plzzz
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Regards,
>>>>>>>>>>>>>>>>> Padmini.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>>>>> mapguide-users mailing list
>>>>>>>>>>>>>>>> mapguide-users at lists.osgeo.org
>>>>>>>>>>>>>>>> http://lists.osgeo.org/mailman/listinfo/mapguide-users
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>> _______________________________________________
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>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>> mapguide-users mailing list
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>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>> _______________________________________________
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>>>>>>>>>> http://lists.osgeo.org/mailman/listinfo/mapguide-users
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>> mapguide-users mailing list
>>>>>>>> mapguide-users at lists.osgeo.org
>>>>>>>> http://lists.osgeo.org/mailman/listinfo/mapguide-users
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
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>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>>
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