[vtkusers] VTK class to do interpolation of scalar values

Bill Lorensen bill.lorensen at gmail.com
Mon Dec 7 16:26:11 EST 2009 

Sure. In paraview.

1) Read your data
2) Delaunay 2D
3) Warp by scalar data
4) Contour


On Mon, Dec 7, 2009 at 4:16 PM, Jesse Kim <jinryongkim at gmail.com> wrote:
> Bill,
>
> What I'm saying is to show iso contour with different height (like warp) so
> that higher contour lines have higher height.
> Is it possible?
>
> Thanks,
>
> Jesse
>
> Bill Lorensen wrote:
>>
>> Your data points seem to all have a z=0.0. If they are scattered in 3D
>> space, then Delaunay3D might do the trick.
>>
>> Bill
>>
>>
>> On Mon, Dec 7, 2009 at 3:49 PM, Jesse Kim <jinryongkim at gmail.com> wrote:
>>
>>>
>>> Bill,
>>>
>>> Thanks so much for your help.
>>>
>>> I think this what I wanted to get. However, I have one more question for
>>> you. Is there any way I can express them in 3D like isosurface? Should I
>>> change it to delaunay3D?
>>>
>>> Thanks,
>>>
>>> Jesse
>>>
>>> Bill Lorensen wrote:
>>>
>>>>
>>>> Jesse,
>>>>
>>>> I loaded your data into paraview (paraview.org), applied the
>>>> Delaunay2D filter->ContourFilter and produced the attached image. Is
>>>> this what you would expect?
>>>>
>>>> Bill
>>>>
>>>>
>>>> On Mon, Dec 7, 2009 at 1:55 PM, Jesse Kim <jinryongkim at gmail.com> wrote:
>>>>
>>>>
>>>>>
>>>>> Hi Bill and David,
>>>>>
>>>>> Thanks for the reply.
>>>>> For the clarification, let me provide my sample data set. What I would
>>>>> like
>>>>> to do here is to do the interpolations among these scalar values
>>>>> associated
>>>>> with some geographical locations (75 locations) so that I can have
>>>>> smooth
>>>>> iso-contour or iso-surface. This the dataset of some geographical
>>>>> locations
>>>>> (75 locations) and their scalar values.
>>>>>
>>>>> # vtk DataFile Version 2.0
>>>>> Weather observing stations
>>>>> ASCII
>>>>> DATASET POLYDATA
>>>>> POINTS 75 float
>>>>> 660.905194 527.736720 0.0
>>>>> 536.263098 683.230547 0.0
>>>>> 702.452710 1112.016367 0.0
>>>>> 710.006701 838.724374 0.0
>>>>> 354.965505 414.650300 0.0
>>>>> 660.905194 862.283951 0.0
>>>>> 694.898493 485.329312 0.0
>>>>> 657.128312 612.551535 0.0
>>>>> 589.141714 975.370370 0.0
>>>>> 490.938700 424.074074 0.0
>>>>> 260.539826 640.823140 0.0
>>>>> 317.195324 805.740741 0.0
>>>>> 260.539826 376.954638 0.0
>>>>> 366.296604 164.917601 0.0
>>>>> 113.235531 75.391041 0.0
>>>>> 128.343513 98.950617 0.0
>>>>> 664.682303 720.925926 0.0
>>>>> 653.351203 932.962963 0.0
>>>>> 358.742613 735.061728 0.0
>>>>> 173.667911 329.835485 0.0
>>>>> 158.559929 1107.3046210 0.0
>>>>> 498.492917 1088.4567900 0.0
>>>>> 294.533125 546.584268 0.0
>>>>> 524.931999 588.991675 0.0
>>>>> 589.141714 466.481481 0.0
>>>>> 524.931999 245.020670 0.0
>>>>> 181.222129 1088.4567900 0.0
>>>>> 256.762717 160.205856 0.0
>>>>> 585.364606 890.555556 0.0
>>>>> 407.844121 574.855873 0.0
>>>>> 528.709108 164.917601 0.0
>>>>> 430.506320 782.181164 0.0
>>>>> 385.181921 862.283951 0.0
>>>>> 608.026805 292.139823 0.0
>>>>> 547.594198 815.164515 0.0
>>>>> 370.073713 480.617284 0.0
>>>>> 298.310007 862.283951 0.0
>>>>> 41.471825 65.966984 0.0
>>>>> 604.249696 711.502152 0.0
>>>>> 162.336811 65.966984 0.0
>>>>> 460.722510 669.094744 0.0
>>>>> 562.702406 367.530864 0.0
>>>>> 347.411514 334.547231 0.0
>>>>> 362.519722 240.308642 0.0
>>>>> 132.120621 669.094744 0.0
>>>>> 177.445020 226.172840 0.0
>>>>> 396.513021 1027.2015520 0.0
>>>>> 67.911133 131.934251 0.0
>>>>> 113.235531 183.765432 0.0
>>>>> 211.438319 914.115132 0.0
>>>>> 725.114910 617.263280 0.0
>>>>> 422.952102 951.810794 0.0
>>>>> 192.553228 584.279930 0.0
>>>>> 596.695705 537.160494 0.0
>>>>> 728.891792 758.621305 0.0
>>>>> 453.168519 259.156473 0.0
>>>>> 521.155117 278.004021 0.0
>>>>> 475.830718 362.818836 0.0
>>>>> 517.378008 518.312663 0.0
>>>>> 290.756016 273.292275 0.0
>>>>> 396.513021 1130.864198 0.0
>>>>> 298.310007 70.679012 0.0
>>>>> 154.782821 499.465115 0.0
>>>>> 237.877627 1079.033016 0.0
>>>>> 679.790511 296.851852 0.0
>>>>> 135.897730 292.139823 0.0
>>>>> 513.600899 871.707725 0.0
>>>>> 502.269800 998.929947 0.0
>>>>> 215.215427 259.156473 0.0
>>>>> 260.539826 768.045362 0.0
>>>>> 245.431617 786.892910 0.0
>>>>> 218.992309 989.506173 0.0
>>>>> 392.735912 650.246914 0.0
>>>>> 324.749315 310.987654 0.0
>>>>> 339.857523 942.386737 0.0
>>>>> POINT_DATA 75
>>>>> SCALARS req_prep_0 float
>>>>> LOOKUP_TABLE default
>>>>> 184.949631
>>>>> 125.071189
>>>>> 114.655333
>>>>> 142.508891
>>>>> 250.255094
>>>>> 132.980147
>>>>> 132.369983
>>>>> 104.52796
>>>>> 331.737495
>>>>> 336.049583
>>>>> 214.249765
>>>>> 117.033152
>>>>> 329.449907
>>>>> 266.396892
>>>>> 147.324093
>>>>> 293.163118
>>>>> 104.33426
>>>>> 313.719804
>>>>> 207.564979
>>>>> 109.947172
>>>>> 143.08005
>>>>> 143.859373
>>>>> 189.977409
>>>>> 126.483623
>>>>> 217.989847
>>>>> 372.728658
>>>>> 343.744282
>>>>> 94.816421
>>>>> 187.774541
>>>>> 186.499795
>>>>> 337.102472
>>>>> 182.862572
>>>>> 125.000005
>>>>> 520.225266
>>>>> 267.150263
>>>>> 104.699336
>>>>> 187.176938
>>>>> 111.811702
>>>>> 314.11783
>>>>> 463.261076
>>>>> 131.671659
>>>>> 361.803069
>>>>> 272.000024
>>>>> 178.927209
>>>>> 274.940403
>>>>> 176.914528
>>>>> 249.996726
>>>>> 225.34729
>>>>> 220.164636
>>>>> 192.443055
>>>>> 274.59666
>>>>> 242.720081
>>>>> 163.316313
>>>>> 214.000012
>>>>> 150.596283
>>>>> 274.416211
>>>>> 532.135911
>>>>> 453.662097
>>>>> 229.363398
>>>>> 733.273974
>>>>> 151.398179
>>>>> 162.908337
>>>>> 244.352757
>>>>> 332.847796
>>>>> 480.445379
>>>>> 541.82268
>>>>> 384.111595
>>>>> 201.312356
>>>>> 234.118599
>>>>> 185.278497
>>>>> 159.692496
>>>>> 281.602642
>>>>> 356.659038
>>>>> 377.949511
>>>>> 469.000015
>>>>>
>>>>> Bill Lorensen wrote:
>>>>>
>>>>>
>>>>>>
>>>>>> The data for the example should be some points scattered in space. I
>>>>>> assume that is what Jin has, not just three points on a line. I'll dig
>>>>>> up some meaningful data, uless Jin can share a small sample of his
>>>>>> data.
>>>>>>
>>>>>> Bill
>>>>>>
>>>>>> Bill
>>>>>>
>>>>>> On Mon, Dec 7, 2009 at 1:11 PM, David Doria <daviddoria+vtk at gmail.com>
>>>>>> wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>>
>>>>>>> On Mon, Dec 7, 2009 at 12:20 PM, David Gobbi <david.gobbi at gmail.com>
>>>>>>> wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>> On Mon, Dec 7, 2009 at 9:51 AM, David Doria
>>>>>>>> <daviddoria+vtk at gmail.com>
>>>>>>>> wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Mon, Dec 7, 2009 at 11:43 AM, Jin Ryong Kim
>>>>>>>>> <jinryongkim at gmail.com>
>>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> I have a question about interpolation method in VTK.
>>>>>>>>>> Currently, I'm trying to interpolate scalar values between data
>>>>>>>>>> points
>>>>>>>>>> to
>>>>>>>>>> create a contour map.
>>>>>>>>>> I have some data points set (x, y, z) and scalar values related
>>>>>>>>>> with
>>>>>>>>>> each
>>>>>>>>>> data point.
>>>>>>>>>> So far, I found out vtkProbeFilter but when I tried, nothing came
>>>>>>>>>> up.
>>>>>>>>>> My questions are as follow.
>>>>>>>>>> 1. Is vtkProbeFilter the right choice in this case?
>>>>>>>>>> 2. If not, what are the right vtk classes to accomplish such a
>>>>>>>>>> goal?
>>>>>>>>>> If anyone has the solution for this, please let me know.
>>>>>>>>>> Thanks in advance!
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Jin,
>>>>>>>>>
>>>>>>>>> If I'm not mistaken you sent this same question yesterday. I am
>>>>>>>>> interesting in making an example of this so I have started poking
>>>>>>>>> around. I understand that you may be in a hurry, but asking twice
>>>>>>>>> is
>>>>>>>>> just going to annoy people on the list, making your answer come
>>>>>>>>> slower, not faster.
>>>>>>>>>
>>>>>>>>> Can anyone confirm or deny that ProbeFilter is the right way to go?
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>> The probe needs cells to interpolate the data.  If all you have is
>>>>>>>> points, then you have to apply delaunay first to make the cells, and
>>>>>>>> then use probe to interpolate the data onto a grid (i.e. make an
>>>>>>>> image), and then contour the grid.  It might also be possible to
>>>>>>>> contour directly from the output of delaunay, but I'm not sure
>>>>>>>> whether
>>>>>>>> VTK can do that.  I'm no expert in this area, but hopefully I've
>>>>>>>> answered your question.
>>>>>>>>
>>>>>>>>  David
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>> From Bill's suggestion I have tried to make an example:
>>>>>>> http://www.vtk.org/Wiki/VTK_Examples_Interpolation
>>>>>>>
>>>>>>> the problem is that the Shepard filter outputs an ImageData and the
>>>>>>> ContourFilter seems to expect a DataObject.
>>>>>>>
>>>>>>> Jin, this is a simple version of what you are trying to do, correct?
>>>>>>> If so, let try to get this little demo working.
>>>>>>>
>>>>>>> Thanks,
>>>>>>>
>>>>>>> David
>>>>>>> _______________________________________________
>>>>>>> Powered by www.kitware.com
>>>>>>>
>>>>>>> Visit other Kitware open-source projects at
>>>>>>> http://www.kitware.com/opensource/opensource.html
>>>>>>>
>>>>>>> Please keep messages on-topic and check the VTK FAQ at:
>>>>>>> http://www.vtk.org/Wiki/VTK_FAQ
>>>>>>>
>>>>>>> Follow this link to subscribe/unsubscribe:
>>>>>>> http://www.vtk.org/mailman/listinfo/vtkusers
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> Powered by www.kitware.com
>>>>>>
>>>>>> Visit other Kitware open-source projects at
>>>>>> http://www.kitware.com/opensource/opensource.html
>>>>>>
>>>>>> Please keep messages on-topic and check the VTK FAQ at:
>>>>>> http://www.vtk.org/Wiki/VTK_FAQ
>>>>>>
>>>>>> Follow this link to subscribe/unsubscribe:
>>>>>> http://www.vtk.org/mailman/listinfo/vtkusers
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> ------------------------------------------------------------------------
>>>>>
>>>>>
>>>
>>>
>>
>>
>
>

More information about the vtkusers mailing list