[vtkusers] Extract csv row and column into points

[Polly Pui]

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<mailto: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
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--
Cory Quammen
Staff R&D Engineer
Kitware, Inc.
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