Skip to content

LinePlot

vtk-examples/Cxx/Plotting/LinePlot


Description

This example demonstrates how to plot XY data.

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

LinePlot.cxx

#include <vtkChartXY.h>
#include <vtkContextScene.h>
#include <vtkContextView.h>
#include <vtkFloatArray.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPen.h>
#include <vtkPlot.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkTable.h>

int main(int, char*[])
{
  vtkNew<vtkNamedColors> colors;

  // Create a table with some points in it.
  vtkNew<vtkTable> table;

  vtkNew<vtkFloatArray> arrX;
  arrX->SetName("X Axis");
  table->AddColumn(arrX);

  vtkNew<vtkFloatArray> arrC;
  arrC->SetName("Cosine");
  table->AddColumn(arrC);

  vtkNew<vtkFloatArray> arrS;
  arrS->SetName("Sine");
  table->AddColumn(arrS);

  // Fill in the table with some example values.
  int numPoints = 69;
  float inc = 7.5 / (numPoints - 1);
  table->SetNumberOfRows(numPoints);
  for (int i = 0; i < numPoints; ++i)
  {
    table->SetValue(i, 0, i * inc);
    table->SetValue(i, 1, cos(i * inc));
    table->SetValue(i, 2, sin(i * inc));
  }

  // Set up the view
  vtkNew<vtkContextView> view;
  view->GetRenderWindow()->SetWindowName("LinePlot");
  view->GetRenderer()->SetBackground(colors->GetColor3d("SlateGray").GetData());

  // Add multiple line plots, setting the colors etc.
  vtkNew<vtkChartXY> chart;
  view->GetScene()->AddItem(chart);
  vtkPlot* line = chart->AddPlot(vtkChart::LINE);
  line->SetInputData(table, 0, 1);
  line->SetColor(0, 255, 0, 255);
  line->SetWidth(1.0);
  line = chart->AddPlot(vtkChart::LINE);
  line->SetInputData(table, 0, 2);
  line->SetColor(255, 0, 0, 255);
  line->SetWidth(5.0);

  // For dotted line, the line type can be from 2 to 5 for different dash/dot
  // patterns (see enum in vtkPen containing DASH_LINE, value 2):
  // #ifndef WIN32
  //   line->GetPen()->SetLineType(vtkPen::DASH_LINE);
  // #endif
  // (ifdef-ed out on Windows because DASH_LINE does not work on Windows
  //  machines with built-in Intel HD graphics card...)

  // view->GetRenderWindow()->SetMultiSamples(0);

  // Start interactor
  view->GetRenderWindow()->Render();
  view->GetInteractor()->Initialize();
  view->GetInteractor()->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(LinePlot)

find_package(VTK COMPONENTS 
  vtkChartsCore
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkInteractionStyle
  vtkRenderingContext2D
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2
  vtkViewsContext2D
  QUIET
)

if (NOT VTK_FOUND)
  message("Skipping LinePlot: ${VTK_NOT_FOUND_MESSAGE}")
  return ()
endif()
message (STATUS "VTK_VERSION: ${VTK_VERSION}")
if (VTK_VERSION VERSION_LESS "8.90.0")
  # old system
  include(${VTK_USE_FILE})
  add_executable(LinePlot MACOSX_BUNDLE LinePlot.cxx )
  target_link_libraries(LinePlot PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(LinePlot MACOSX_BUNDLE LinePlot.cxx )
  target_link_libraries(LinePlot PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS LinePlot
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build LinePlot

Click here to download LinePlot and its CMakeLists.txt file. Once the tarball LinePlot.tar has been downloaded and extracted,

cd LinePlot/build

If VTK is installed:

cmake ..

If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:

cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

Build the project:

make

and run it:

./LinePlot

WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.