VTK: plot line segments - c++

Question

I need to plot line segments (not continous) combined in one chart.
In order to create a plot I use the code from the VTK example but when I skip some values when filling vtkTable line goes down to zero value. And if creating another plot and skip some of the first elements the line goes up from zero. So I need to solve these issues.

Answer 1

I have figured out the solution myself. It appears very simple at last. The basic idea is to represent each line segment by its own plot and to use a separate table for each of the plots. One more improtant point all of the tables do not need to have the same step on the X-axis.
Here is the sample code:
vtkSmartPointer<vtkContextView> view = vtkSmartPointer<vtkContextView>::New();
view->GetRenderer()->SetBackground(1.0, 1.0, 1.0);
vtkSmartPointer<vtkChartXY> chart = vtkSmartPointer<vtkChartXY>::New();
vtkSmartPointer<vtkTable> table1 = vtkSmartPointer<vtkTable>::New();
vtkSmartPointer<vtkFloatArray> xAxis1 = vtkSmartPointer<vtkFloatArray>::New();
xAxis1->SetName("X");
vtkSmartPointer<vtkFloatArray> yAxis1 = vtkSmartPointer<vtkFloatArray>::New();
yAxis1->SetName("");
table1->AddColumn(xAxis1);
table1->AddColumn(yAxis1);
table1->SetNumberOfRows(2);
table1->SetValue(0, 0, 1);
table1->SetValue(0, 1, 1);
table1->SetValue(1, 0, 2);
table1->SetValue(1, 1, 2);
vtkPlot* plot1 = chart->AddPlot(vtkChart::LINE);
plot1->SetInputData(table1, 0, 1);
plot1->SetColor(0, 0, 255, 255);
vtkSmartPointer<vtkTable> table2 = vtkSmartPointer<vtkTable>::New();
vtkSmartPointer<vtkFloatArray> xAxis2 = vtkSmartPointer<vtkFloatArray>::New();
xAxis2->SetName("X");
vtkSmartPointer<vtkFloatArray> yAxis2 = vtkSmartPointer<vtkFloatArray>::New();
yAxis2->SetName("");
table2->AddColumn(xAxis2);
table2->AddColumn(yAxis2);
table2->SetNumberOfRows(3);
table2->SetValue(0, 0, 4);
table2->SetValue(0, 1, 4);
table2->SetValue(1, 0, 5);
table2->SetValue(1, 1, 5);
table2->SetValue(2, 0, 6);
table2->SetValue(2, 1, 6);
vtkPlot* plot2 = chart->AddPlot(vtkChart::LINE);
plot2->SetInputData(table2, 0, 1);
plot2->SetColor(255, 0, 0, 255);
view->GetScene()->AddItem(chart);
view->GetInteractor()->Initialize();
view->GetInteractor()->Start();
P.S. You can also specify several rows with the same x coordinate.