[vtkusers] Drawing a simple line graph

[beth at portugalmail.pt]

Hi,
 
I'm trying to create a simple line graph. For that, I created a polyline and 2 
axis.My piece of code looks like this:
 
// Create a polyline
 vtkPolyData* polydata = vtkPolyData::New();
 polydata->SetPoints(polyLinePoints);
 polydata->SetLines(line);
 
// Maps it to 2D
 vtkPolyDataMapper2D *mapper = vtkPolyDataMapper2D::New();
 mapper->SetInput(polydata);
 
// Creates an actor, defining its limits according the graph area defined by 
the axes below
 vtkActor2D *actor = vtkActor2D::New();
 actor->SetMapper(mapper);
 actor->GetPositionCoordinate()->SetCoordinateSystemToNormalizedViewport();
 actor->GetPositionCoordinate()->SetValue(0.05, 0.2);
 actor->GetPosition2Coordinate()->SetCoordinateSystemToNormalizedViewport
(); // it's not working properly!!!
 actor->GetPosition2Coordinate()->SetValue(0.90, 0.9); // it's not working 
properly!!!
 actor->GetProperty()->SetColor(1, 0, 0);

// Define axes
 vtkCoordinate *coords_x1 = vtkCoordinate::New();
 coords_x1->SetValue(0.05, 0.2);
 
 vtkCoordinate *coords_x2 = vtkCoordinate::New();
 coords_x2->SetValue(0.95, 0.2);
 
 vtkCoordinate *coords_y1 = vtkCoordinate::New();
 coords_y1->SetValue(0.05, 0.2);
 
 vtkCoordinate *coords_y2 = vtkCoordinate::New();
 coords_y2->SetValue(0.05, 0.95);
 
 vtkAxisActor2D *axesX = vtkAxisActor2D::New();
 axesX->SetPoint1(coords_x1->GetValue());
 axesX->SetPoint2(coords_x2->GetValue());
 axesX->SetLabelFormat("%3.2f");
 axesX->SetFontFactor(1.2);
 axesX->SetRange(0, t); // t is the maximum x value in the polyline points
 axesX->SetTitle("Time (s)");
 axesX->SetNumberOfLabels(10);
 axesX->AdjustLabelsOn();
 axesX->LabelVisibilityOn();
 axesX->TickVisibilityOn();
 
 vtkAxisActor2D *axesY = vtkAxisActor2D::New();
 axesY->SetPoint1(coords_y1->GetValue());
 axesY->SetPoint2(coords_y2->GetValue());
 axesY->SetLabelFormat("%3.2f");
 axesY->SetFontFactor(1);
 axesY->SetRange(0, sCardMax); // Máximum y value in polyline points
 axesY->AdjustLabelsOn();
 axesY->LabelVisibilityOn();
 axesY->TickVisibilityOn();
 
.....the usual stuff....creates the renderer...
 
rw->AddActor2D(actor);
rw->AddViewProp(axesX);
rw->AddViewProp(axesY);
 
 
Well, the line graph is drawn, but the problem is that axes values and line 
values are not matching. 
It seems that the GetPosition2Coordinate is not working at all, because the 
mapping of the line to the graph effective area (that is defined by the limits 
of the axes - xmin, ymin and xmax, ymax) is not being done. It just puts the 
polyline at the initial position defined by GetPositionCoordinate, and draws 
it as the output given by the vtkPolyDataMapper2D.
 
What should I do?
 
Thanks for any help!
 
Regards,
 
Elizabeth

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