[vtkusers] Extract csv row and column into points

[Cory Quammen]

Ah, so you want to use the vtkKMeansStatistics filter. That filter operates
on vtkTable data. To use it, you don't need to create points at all.
Instead, you can connect the  vtkDelimitedTextReader directly to the
vtkKMeansStatistics
filter like so:

vtkSmartPointer<vtkKMeansStatistics> kMeansStatistics =
 vtkSmartPointer<vtkKMeansStatistics>::New();
kMeansStatistics->SetInputConnection(reader->GetOutputPort());
kMeansStatistics->SetColumnStatus("column1", 1);
kMeansStatistics->SetColumnStatus("column2", 1);
kMeansStatistics->SetColumnStatus("column3, 1);
kMeansStatistics->RequestSelectedColumns();
kMeansStatistics->SetAssessOption(true);
kMeansStatistics->SetDefaultNumberOfClusters(1);
//kMeansStatistics->SetMaxNumIterations(15);
kMeansStatistics->Update();

Here, I've altered your calls to SetColumnStatus() under the assumption you
know the column names of interest.

HTH,
Cory


On Fri, Nov 9, 2018 at 10:16 AM Polly Pui <polly_sukting at hotmail.com> wrote:

> Hi,
> Thanks for your reply.
> Is it possible to have more elaborations from you?
>
> How can I get the number of points from vtkTableToPolyData?
> I got an error saying that vtkTableToPolyData has no members of
> GetNumberOfPoints.
> I need those points to proceed to KmeansStatistics.
>
> This is my code:
> ......
> std::string inputFilename = argv[1];
>
> vtkSmartPointer<vtkDelimitedTextReader> reader =
>  vtkSmartPointer<vtkDelimitedTextReader>::New();
> reader->SetFileName(inputFilename.c_str());
> reader->SetFieldDelimiterCharacters(" ");
> reader->DetectNumericColumnsOn();
> reader->Update();
> int numberOfRows = reader->GetOutput()->GetNumberOfRows();
>
> vtkSmartPointer<vtkTableToPolyData> inputData =
>  vtkSmartPointer<vtkTableToPolyData>::New();
> inputData->SetInputConnection(reader->GetOutputPort);
>
> for (int c = 0; c < 3; ++c)
> {
>  std::stringstream colName;
>  colName << "coord " << c;
>  vtkSmartPointer<vtkDoubleArray> doubleArray =
>   vtkSmartPointer<vtkDoubleArray>::New();
>  doubleArray->SetNumberOfComponents(1);
>  doubleArray->SetName(colName.str().c_str());
>  doubleArray->SetNumberOfTuples(inputData->GetNumberOfPoints());
>
>
>  for (int r = 0; r < inputData->GetNumberOfPoints(); ++r)
>  {
>   double p[3];
>   inputData->GetPoint(r, p);
>   doubleArray->SetValue(r, p[c]);
>  }
>  inputData->AddColumn(doubleArray);
> }
>
> vtkSmartPointer<vtkKMeansStatistics> kMeansStatistics =
>  vtkSmartPointer<vtkKMeansStatistics>::New();
>
> #if VTK_MAJOR_VERSION <= 5
> kMeansStatistics->SetInput(vtkStatisticsAlgorithm::INPUT_DATA, inputData);
> #else
> kMeansStatistics->SetInputData(vtkStatisticsAlgorithm::INPUT_DATA,
> inputData);
> #endif
> kMeansStatistics->SetColumnStatus(inputData->GetColumnName(0), 1);
> kMeansStatistics->SetColumnStatus(inputData->GetColumnName(1), 1);
> kMeansStatistics->SetColumnStatus(inputData->GetColumnName(2), 1);
> kMeansStatistics->RequestSelectedColumns();
> kMeansStatistics->SetAssessOption(true);
> kMeansStatistics->SetDefaultNumberOfClusters(1);
> //kMeansStatistics->SetMaxNumIterations(15);
> kMeansStatistics->Update();
>
> Thanks again.
>
> Regards,
> Polly
> ------------------------------
> *From:* Cory Quammen <cory.quammen at kitware.com>
> *Sent:* Friday, November 9, 2018 10:07 PM
> *To:* Polly Pui
> *Cc:* vtkusers
> *Subject:* Re: [vtkusers] Extract csv row and column into points
>
> vtkDelimitedTextReader -> vtkTableToPolyData is a pipeline that should
> make this much simpler.
>
> On Fri, Nov 9, 2018 at 1:14 AM Polly Pui <polly_sukting at hotmail.com>
> wrote:
>
> Hi,
> Is there any clue that i can extract the row and column data from a csv
> file and read them as points?
> Currently I am using vtkpoints to read points by inserting points
> manually to my .cpp .
> Is it possible for me to call the csv directly and read the data (eg.
> column 3-5, row 2-10)?
>
> I attach my code here.
> ......
> int main(int, char*[])
> {
>
> vtkSmartPointer<vtkPoints> points =
>  vtkSmartPointer<vtkPoints>::New();
> points->InsertNextPoint(8.4312, -36.489, -1500.7);
> points->InsertNextPoint(8.8408, -37.726, -1500.4);
> points->InsertNextPoint(11.372, -37.787, -1501.5);
> points->InsertNextPoint(11.263, -36.384, -1501.9);
> points->InsertNextPoint(9.3914, -40.819, -1500.8);
> points->InsertNextPoint(11.685, -42.482, -1502.7);
> points->InsertNextPoint(14.235, -38.096, -1503.5);
> points->InsertNextPoint(13.972, -43.051, -1504.2);
> points->InsertNextPoint(9.22, -43.904, -1504);
>
> vtkSmartPointer<vtkTable> inputData =
>  vtkSmartPointer<vtkTable>::New();
> for (int c = 0; c < 3; ++c)
> {
>  std::stringstream colName;
>  colName << "coord " << c;
>  vtkSmartPointer<vtkDoubleArray> doubleArray =
>   vtkSmartPointer<vtkDoubleArray>::New();
>  doubleArray->SetNumberOfComponents(1);
>  doubleArray->SetName(colName.str().c_str());
>  doubleArray->SetNumberOfTuples(points->GetNumberOfPoints());
>
>  for (int r = 0; r < points->GetNumberOfPoints(); ++r)
>  {
>   double p[3];
>   points->GetPoint(r, p);
>   doubleArray->SetValue(r, p[c]);
>  }
>  inputData->AddColumn(doubleArray);
> }
>
> Thank you very much.
>
> Regards,
> Polly
> _______________________________________________
> 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
>
> Search the list archives at: http://markmail.org/search/?q=vtkusers
>
> Follow this link to subscribe/unsubscribe:
> https://public.kitware.com/mailman/listinfo/vtkusers
>
>
>
> --
> Cory Quammen
> Staff R&D Engineer
> Kitware, Inc.
>


-- 
Cory Quammen
Staff R&D Engineer
Kitware, Inc.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://public.kitware.com/pipermail/vtkusers/attachments/20181113/3a237b7b/attachment.html>