<br><br><blockquote>Hi,<br><br>As far as my knowledge is concerned, a point with unknown value can lye either inside a range [min, max] or outsie the range [min, max].<br><br>If the point lies inside the range, then using interpolation we can find the unknow value for that point.. And if the point lies outside the range,<br>then, using extrapolation technique, we find the unknown value for that point.. I guess I'm right.. If i'm wrong please tell me..<br><br>Here in my case, i need to find the same elevation at lat/lons for all the node points on my mesh.. I guess inverse weighted method should do the need.<br><br>I also read that shepard method uses inverse weighted method, but it doesnt suffice my need.. I hope my problem is clear.. What values it finds for the nodes<br>inside the range, the same value i want to be found for the node points that fall outside the range..<br><br>I've seen that some plottin tools have the capability to do this... But i'm blank about how that
is done.. I have implemented the linear interpolation<br>method and it works fine. It interpolates and gets the values for all points (inside and outside).. But it takes hell amount of time.. So, i want to overcome the speed.<br><br>Any idea or suggestions..??<br><br>Thanks<br><br>Regards<br>Rakesh Patil<br>---------- Original message ----------<br>From:Bill Lorensen< bill.lorensen@gmail.com ><br>Date: 26 Apr 10 17:35:48<br>Subject: Re: [vtkusers] Interpolation of data..<br>To: Rakesh Patil <rakeshthp@in.com><br><br>What values would you expect in area where you have no elevation data?<br><br>Maybe I misunderstand the problem.<br><br>On Sun, Apr 25, 2010 at 9:45 PM, Rakesh Patil <rakeshthp@in.com> wrote:<br>><br>><br>> Hi,<br>><br>> So, you mean there is no other way..?? extrapolation or anything..??<br>><br>> In that case i need to write my own filter to do this then..??<br>><br>> Thanks<br>><br>> Regards<br>> Rakesh Patil<br>>
---------- Original message ----------<br>> From:Bill Lorensen< bill.lorensen@gmail.com ><br>> Date: 26 Apr 10 02:13:14<br>> Subject: Re: [vtkusers] Interpolation of data..<br>> To: Rakesh Patil<br>><br>> If you do not have data in a region, I don't see how you can interpolate it.<br>><br>> On Sun, Apr 25, 2010 at 1:54 PM, Rakesh Patil wrote:<br>>><br>>><br>>> Hi Bill,<br>>><br>>> Thanks for your reply.. I implemented that technique and it works fine. As<br>>> i<br>>> said in my previous post, outsid range values are not interpolated.<br>>><br>>> For example, pls see the attached image file for reference.. In the<br>>> figure,<br>>> the mesh which is generated, doesnt completely fall in the area of the<br>>> scatter data..<br>>> In the rwo white patches, the values are not interpolated. I mean i dont<br>>> get<br>>> the actual result there in those areas (a
s there is no scatter points<br>>> avail<br>>> there)<br>>><br>>> So, what can i do to get values for my entire mesh instead of getitng for<br>>> partial mesh.??Either interolation or extrapolation.. Any means is<br>>> available<br>>> in VTK<br>>> to implement this..??<br>>><br>>> Thanks<br>>><br>>> Regards<br>>> Rakesh Patil<br>>> ---------- Original message ----------<br>>> From:Bill Lorensen< bill.lorensen@gmail.com ><br>>> Date: 24 Apr 10 18:15:33<br>>> Subject: Re: [vtkusers] Interpolation of data..<br>>> To: Rakesh Patil<br>>><br>>> The last part of this example:<br>>> <a target=\"_blank\" href="http://www.vtk.org/Wiki/VTK/Examples/InterpolateTerrain" target="_blank">http://www.vtk.org/Wiki/VTK/Examples/InterpolateTerrain</a><br>>> does what you want.<br>>><br>>> Basically,<br>>> 1) Add the lat/lo g and elevations t
o a polydata<br>>> 2) Create a surface with Delaunay2D<br>>> 3) Add the points with unknown elevation to a vtkPoints<br>>> 4) Use a cell locator to cast infinite rays into the surface to find<br>>> the elevation.<br>>><br>>><br>>> On Fri, Apr 23, 2010 at 9:50 PM, Rakesh Patil wrote:<br>>>><br>>>><br>>>> Well,<br>>>><br>>>> I was trying with this example:<br>>>><br>>>> <a target=\"_blank\" href="http://www.vtk.org/Wiki/VTK/Examples/InterpolateTerrain" target="_blank">http://www.vtk.org/Wiki/VTK/Examples/InterpolateTerrain</a><br>>>><br>>>> In this example, there are two ways specified for interpolation.. One is<br>>>> using<br>>>> vtkProbeFilter and another is using vtkCellLocator<br>>>><br>>>> First i tried using vtkProbeFilter. But failed getting the output.. But<br>>>> using the<br>>>> vtkCellLocato
r, i was able to produce interpolated values for the third<br>>>> column of MeshG.<br>>>><br>>>> After observation, i foound that only the region which is common in both<br>>>> the<br>>>> grids,<br>>>> was interpolated. So i was fully stuck wondering how to find the<br>>>> remaining<br>>>> values..<br>>>><br>>>> any comments..??<br>>>><br>>>> Thanks<br>>>><br>>>> Rakesh Patil<br>>>><br>>>> ---------- Original message ----------<br>>>> From:"Dean Inglis"< dean.inglis@camris.ca ><br>>>> Date: 23 Apr 10 23:59:48<br>>>> Subject: Re: Re:[vtkusers]Interpolation of data..<br>>>> To: "Rakesh Patil"<br>>>><br>>>> How can you expect your mesh to get interpolated<br>>>> when its z coordinate values are all 0<br>>>> but the scatter data range in z from -700 to -900?<br
>>>> The bounds of each unstructured grid do not even<br>>>> overlap / intersect!<br>>>><br>>>> Dean<br>>>><br>>>>> Hi,My both the meshes are uns tructured grid. My application is based on<br>>>>> FEA meth od.. ScatterG does contains scalars and the depth values are<br>>>>> stored as a scalar array for scatterG..I dont want coordinate values to<br>>>>> be<br>>>>> interpolated.. As an example,scatterG contains data something like<br>>>>> this,Points: 87.23 16.2690086.24 17.8753087.18 17.27700......and the<br>>>>> scalar for scatterG is defined as 900530700......meshG contains<br>>>>> points84.1217.83 081.3315.28 083.2418.28 0......So,, what i want to do<br>>>>> is,<br>>>>> using the third column of scatterG, i need to estimate the third column<br>>>>> of<br>>>>> meshG..Any ideas how it can
be done.??ThanksRakesh Patil Original<br>>>>> message<br>>>>> From:"De an Inglis"< dean.inglis@camris.ca >Date: 23 Apr 10<br>>>>> 20:16:47Subject:Re: Re:[vtkusers]Interpolation of data..To: "Rakesh<br>>>>> Patil"<br>>>>& gt; vtkProbeFlter will probe the scalar values ateach spatial location<br>>>> of<br>>>>> your<br>>>>> scattered points: youneed to have scalar, vector, or tensor data<br>>>>> asso ciatedwith the grid's points:scatterG>GetPointData()>SetScalars(<br>>>>> somevt<br>>>>> kDataArray );the vtkProbeFilter will not interpolate any<br>>>>> coordinatevalues<br>>>>> like x , y,z locations.If you have depth valuesin a vtkDataArray that<br>>>>> correspond to the x, y, z locationsin your scatterG grid, then this<br>>>>> should<br>>>>> work.Does anyone know ifmaybe the input
to the probe filter needs to be<br>>>>> a<br>>>>> structured data set likevtkPolyData? By the sound of your grid's name<br>>>>> "mesh" , this sounds like structureddata.Can it be converted to a<br>>>>> vtkPolyData?Also, you allocate a smart pointer as:vtkSmartPointer probe<br>>>>> =<br>>>>> vtkSmartPointer: :New()Dean Original Message From: "Rakesh Patil" To:<br>>>>> Cc:<br>>>>> Sent: Friday, April 23, 2010 9:40 AMSubject: Re: Re:[vtkusers]<br>>>>> Interpolation of data..> Hi..I can independently view those grids...<br>>>>> This<br>>>>> is what I have done..vtkUnstructuredGrid *scatterG =<br>>>>> MyApp::getInstance()>getScatterGrid();vtkUnstructuredGrid *meshG =<br>>>>> MyApp::getInstance()>getMeshGrid();vtkSmartPointer probe =<br>>>>><br>>>>><br>>>>><br>>>>> vtkSm
artPointer::New();probe>SetSource(scatterG);probe>SetInput(meshG);probe>Update();vtkDataArr<br>>>>> ay *data = probe>GetOutput()>GetPointData()>GetScalar();vtkDoubleArray<br>>>>> *doubleArray =<br>>>>><br>>>>><br>>>>><br>>>>> vtkDoubleArray::SafeDownCast(data);MyContour::getInstance()>setDisplayArray(doubleArray);After<br>>>>> doing this, i click on contour display button, and the contour for<br>>>>> bathymetry gets displayed for meshG .Initially, meshG doesnt have<br>>>>> depth/elevation (z) value. z value is always 0 for every node point. x<br>>>>> and<br>>>>> y corresponds to the lon and lat respectively.But the scatter data<br>>>>> contains lon, lat, and depth.. So, once the interpolation is done, i<br>>>>> should get the bathymetry (depth/elevation) for meshG also..'MyContour'<br>>>>>
in<br>>>>> the above code is the class which displays the contours for wh> atever<br>>>>> data is being passed.So, any suggestions or > comments..??ThanksRegards<br>>>>> Rakesh Patil Original messageFrom:Dean Inglis< > dean.inglis@camris.ca ><br>>>>> Date: 23 Apr 10 16:49:50 Subject:Re: > Re:[vtkusers]Interpolation of<br>>>>> data.. To: "Rakesh Patil"><br>>>>><br>>>><br>>>><br>>>> _______________________________________________<br>>>> Powered by <a target=\"_blank\" href="http://www.kitware.com" target="_blank">www.kitware.com</a><br>>>><br>>>> Visit other Kitware open-source projects at<br>>>> <a target=\"_blank\" href="http://www.kitware.com/opensource/opensource.html" target="_blank">http://www.kitware.com/opensource/opensource.html</a><br>>>><br>>>> Please keep messages on-topic and check the VTK FA
Q at:<br>>>> htt p://www.vtk.org/Wiki/VTK_FAQ<br>>>><br>>>> Follow this link to subscribe/unsubscribe:<br>>>> <a target=\"_blank\" href="http://www.vtk.org/mailman/listinfo/vtkusers" target="_blank">http://www.vtk.org/mailman/listinfo/vtkusers</a><br>>>><br>>>><br>>><br>><br></rakeshthp@in.com></rakeshthp@in.com></blockquote>