[vtkusers] Interpolation of data..

[Rakesh Patil]

 Hi,So, you mean there is no other way..?? extrapolation or anything..??In that case i need to write my own filter to do this then..??ThanksRegardsRakesh Patil Original message From:Bill Lorensen< bill.lorensen at gmail.com >Date: 26 Apr 10 02:13:14Subject:Re: [vtkusers] Interpolation of data..To: Rakesh Patil If you do not have data in a region, I don't see how you can interpolate it.On Sun, Apr 25, 2010 at 1:54 PM, Rakesh Patilwrote:>>> Hi Bill,>> Thanks for your reply.. I implemented that technique and it works fine. As i> said in my previous post, outsid range values are not interpolated.>> For example, pls see the attached image file for reference.. In the figure,> the mesh which is generated, doesnt completely fall in the area of the> scatter data..> In the rwo white patches, the values are not interpolated. I mean i dont get> the actual result there in those areas (as there is no scatter points avail> there)>> So, what can i do to get values for my entire mesh instead of 
 getitng for> partial mesh.??Either interolation or extrapolation.. Any means is available> in VTK> to implement this..??>> Thanks>> Regards> Rakesh Patil>  Original message > From:Bill Lorensen< bill.lorensen at gmail.com >> Date: 24 Apr 10 18:15:33> Subject: Re: [vtkusers] Interpolation of data..> To: Rakesh Patil>> The last part of this example:> http://www.vtk.org/Wiki/VTK/Examples/InterpolateTerrain> does what you want.>> Basically,> 1) Add the lat/log and elevations to a polydata> 2) Create a surface with Delaunay2D> 3) Add the points with unknown elevation to a vtkPoints> 4) Use a cell locator to cast infinite rays into the surface to find> the elevation.>>> On Fri, Apr 23, 2010 at 9:50 PM, Rakesh Patil wrote:>>>>>> Well,>>>> I was trying with this example:>>>> http://www.vtk.org/Wiki/VTK/Examples/InterpolateTerrain>>>> In this example, there are two ways specified for interpolation.. One is>> using>> vtkProbeFilter and another is using vtkCellLocator>>>> First i tried us
 ing vtkProbeFilter. But failed getting the output.. But>> using the>> vtkCellLocator, i was able to produce interpolated values for the third>> column of MeshG.>>>> After observation, i foound that only the region which is common in both>> the>> grids,>> was interpolated. So i was fully stuck wondering how to find the remaining>> values..>>>> any comments..??>>>> Thanks>>>> Rakesh Patil>>>>  Original message >> From:"Dean Inglis"< dean.inglis at camris.ca >>> Date: 23 Apr 10 23:59:48>> Subject: Re: Re:[vtkusers]Interpolation of data..>> To: "Rakesh Patil">>>> How can you expect your mesh to get interpolated>> when its z coordinate values are all 0>> but the scatter data range in z from 700 to 900?>> The bounds of each unstructured grid do not even>> overlap / intersect!>>>> Dean>>>>> Hi,My both the meshes are unstructured grid. My application is based on>>> FEA meth od.. ScatterG does contains scalars and the depth values are>>> stored as a scalar array for scatterG..I dont wan
 t coordinate values to>>> be>>> interpolated.. As an example,scatterG contains data something like>>> this,Points: 87.23 16.2690086.24 17.8753087.18 17.27700......and the>>> scalar for scatterG is defined as 900530700......meshG contains>>> points84.1217.83 081.3315.28 083.2418.28 0......So,, what i want to do>>> is,>>> using the third column of scatterG, i need to estimate the third column>>> of>>> meshG..Any ideas how it can be done.??ThanksRakesh Patil Original message>>> From:"De an Inglis"< dean.inglis at camris.ca >Date: 23 Apr 10>>> 20:16:47Subject:Re: Re:[vtkusers]Interpolation of data..To: "Rakesh>>> Patil">>> vtkProbeFlter will probe the scalar values ateach spatial location of>>> your>>> scattered points: youneed to have scalar, vector, or tensor data>>> asso ciatedwith the grid's points:scatterG>GetPointData()>SetScalars(>>> somevt>>> kDataArray );the vtkProbeFilter will not interpolate any coordinatevalues>>> like x , y,z locations.If you have depth valuesin a vtkD
 ataArray that>>> correspond to the x, y, z locationsin your scatterG grid, then this>>> should>>> work.Does anyone know ifmaybe the input to the probe filter needs to be a>>> structured data set likevtkPolyData? By the sound of your grid's name>>> "mesh" , this sounds like structureddata.Can it be converted to a>>> vtkPolyData?Also, you allocate a smart pointer as:vtkSmartPointer probe =>>> vtkSmartPointer: :New()Dean Original Message From: "Rakesh Patil" To: Cc:>>> Sent: Friday, April 23, 2010 9:40 AMSubject: Re: Re:[vtkusers]>>> Interpolation of data..> Hi..I can independently view those grids... This>>> is what I have done..vtkUnstructuredGrid *scatterG =>>> MyApp::getInstance()>getScatterGrid();vtkUnstructuredGrid *meshG =>>> MyApp::getInstance()>getMeshGrid();vtkSmartPointer probe =>>>>>>>>> vtkSmartPointer::New();probe>SetSource(scatterG);probe>SetInput(meshG);probe>Update();vtkDataArr>>> ay *data = probe>GetOutput()>GetPointData()>GetScalar();vtkDoubleArray>>> *double
 Array =>>>>>>>>> vtkDoubleArray::SafeDownCast(data);MyContour::getInstance()>setDisplayArray(doubleArray);After>>> doing this, i click on contour display button, and the contour for>>> bathymetry gets displayed for meshG.Initially, meshG doesnt have>>> depth/elevation (z) value. z value is always 0 for every node point. x>>> and>>> y corresponds to the lon and lat respectively.But the scatter data>>> contains lon, lat, and depth.. So, once the interpolation is done, i>>> should get the bathymetry (depth/elevation) for meshG also..'MyContour'>>> in>>> the above code is the class which displays the contours for wh> atever>>> data is being passed.So, any suggestions or > comments..??ThanksRegards>>> Rakesh Patil Original messageFrom:Dean Inglis< > dean.inglis at camris.ca >>>> Date: 23 Apr 10 16:49:50 Subject:Re: > Re:[vtkusers]Interpolation of>>> data.. To: "Rakesh Patil">>>>>>>>>> >> Powered by www.kitware.com>>>> Visit other Kitware opensource projects at>> http://www.kitware.c
 om/opensource/opensource.html>>>> Please keep messages ontopic and check the VTK FAQ at:>> htt p://www.vtk.org/Wiki/VTKFAQ>>>> Follow this link to subscribe/unsubscribe:>> http://www.vtk.org/mailman/listinfo/vtkusers>>>>> 
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