ParallelCoordinatesExtraction

VTKExamples/Python/InfoVis/ParallelCoordinatesExtraction


Description

Using Parallel Coordinates View to plot and compare data set attributes, and then using selections in the parallel coordinates view to extract and view data points associated with those selections.###Code ParallelCoordinatesExtraction.py

#!/usr/bin/env python

# Example of how to use Parallel Coordinates View to plot and compare
# data set attributes, and then to use selections in the parallel coordinates
# view to extract and view data points associated with those selections
# Use the "u" character to toggle between "inspect modes" on the parallel
# coordinates view (i.e. between selecting data and manipulating axes)
# Note that no points will show up inside of the 3d box outline until you
# select some lines/curves in the parallel coordinates view

import vtk


def main():
    # Generate an image data set with multiple attribute arrays to probe and view
    rt = vtk.vtkRTAnalyticSource()
    rt.SetWholeExtent(-3, 3, -3, 3, -3, 3)
    grad = vtk.vtkImageGradient()
    grad.SetDimensionality(3)
    grad.SetInputConnection(rt.GetOutputPort())
    brown = vtk.vtkBrownianPoints()
    brown.SetMinimumSpeed(0.5)
    brown.SetMaximumSpeed(1.0)
    brown.SetInputConnection(grad.GetOutputPort())
    elev = vtk.vtkElevationFilter()
    elev.SetLowPoint(-3, -3, -3)
    elev.SetHighPoint(3, 3, 3)
    elev.SetInputConnection(brown.GetOutputPort())

    # Updating here because I will need to probe scalar ranges before
    # the render window updates the pipeline
    elev.Update()

    # Set up parallel coordinates representation to be used in View
    rep = vtk.vtkParallelCoordinatesRepresentation()
    rep.SetInputConnection(elev.GetOutputPort())
    rep.SetInputArrayToProcess(0, 0, 0, 0, 'RTDataGradient')
    rep.SetInputArrayToProcess(1, 0, 0, 0, 'RTData')
    rep.SetInputArrayToProcess(2, 0, 0, 0, 'Elevation')
    rep.SetInputArrayToProcess(3, 0, 0, 0, 'BrownianVectors')
    rep.SetUseCurves(0)  # set to 1 to use smooth curves
    rep.SetLineOpacity(0.5)

    # Set up the Parallel Coordinates View and hook in representation
    view = vtk.vtkParallelCoordinatesView()
    view.SetRepresentation(rep)
    view.SetInspectMode(view.VTK_INSPECT_SELECT_DATA)
    view.SetBrushOperatorToReplace()
    view.SetBrushModeToLasso()

    # Create a annotation link to access selection in parallel coordinates view
    annotationLink = vtk.vtkAnnotationLink()
    # If you don't set the FieldType explicitly it ends up as UNKNOWN
    # (as of 21 Feb 2010)
    # See vtkSelectionNode doc for field and content type enum values
    annotationLink.GetCurrentSelection().GetNode(0).SetFieldType(1)  # Point
    annotationLink.GetCurrentSelection().GetNode(0).SetContentType(4)  # Indices
    # Update before passing annotationLink to vtkExtractSelection
    annotationLink.Update()
    # Connect the annotation link to the parallel coordinates representation
    rep.SetAnnotationLink(annotationLink)

    # Extract portion of data corresponding to parallel coordinates selection
    extract = vtk.vtkExtractSelection()
    extract.SetInputConnection(0, elev.GetOutputPort())
    extract.SetInputConnection(1, annotationLink.GetOutputPort(2))

    def update_render_windows(obj, event):
        """
        Handle updating of RenderWindow since it's not a "View"
        and so not covered by vtkViewUpdater

        :param obj:
        :param event:
        :return:
        """
        # ren.ResetCamera()
        renWin.Render()

    # Set up callback to update 3d render window when selections are changed in
    # parallel coordinates view
    annotationLink.AddObserver("AnnotationChangedEvent", update_render_windows)

    def toggle_inspectors(obj, event):

        if view.GetInspectMode() == 0:
            view.SetInspectMode(1)
        else:
            view.SetInspectMode(0)

    # Set up callback to toggle between inspect modes (manip axes & select data)
    view.GetInteractor().AddObserver("UserEvent", toggle_inspectors)

    # 3D outline of image data bounds
    outline = vtk.vtkOutlineFilter()
    outline.SetInputConnection(elev.GetOutputPort())
    outlineMapper = vtk.vtkPolyDataMapper()
    outlineMapper.SetInputConnection(outline.GetOutputPort())
    outlineActor = vtk.vtkActor()
    outlineActor.SetMapper(outlineMapper)

    # Build the lookup table for the 3d data scalar colors (brown to white)
    lut = vtk.vtkLookupTable()
    lut.SetTableRange(0, 256)
    lut.SetHueRange(0.1, 0.1)
    lut.SetSaturationRange(1.0, 0.1)
    lut.SetValueRange(0.4, 1.0)
    lut.Build()

    # Set up the 3d rendering parameters
    # of the image data which is selected in parallel coordinates
    coloring_by = 'Elevation'
    dataMapper = vtk.vtkDataSetMapper()
    dataMapper.SetInputConnection(extract.GetOutputPort())
    dataMapper.SetScalarModeToUsePointFieldData()
    dataMapper.SetColorModeToMapScalars()
    data = elev.GetOutputDataObject(0).GetPointData()
    dataMapper.ScalarVisibilityOn()
    dataMapper.SetScalarRange(data.GetArray(coloring_by).GetRange())
    dataMapper.SetLookupTable(lut)
    dataMapper.SelectColorArray(coloring_by)
    dataActor = vtk.vtkActor()
    dataActor.SetMapper(dataMapper)
    dataActor.GetProperty().SetRepresentationToPoints()
    dataActor.GetProperty().SetPointSize(10)

    # Set up the 3d render window and add both actors
    ren = vtk.vtkRenderer()
    ren.AddActor(outlineActor)
    ren.AddActor(dataActor)
    renWin = vtk.vtkRenderWindow()
    renWin.AddRenderer(ren)
    iren = vtk.vtkRenderWindowInteractor()
    iren.SetRenderWindow(renWin)
    ren.ResetCamera()
    renWin.Render()

    # Finalize parallel coordinates view and start interaction event loop
    view.GetRenderWindow().SetSize(600, 300)
    view.ResetCamera()
    view.Render()
    view.GetInteractor().Start()


if __name__ == '__main__':
    main()