# LinePlot

VTKExamples/Cxx/Plotting/LinePlot

### Description

This example demonstrates how to plot XY data.

### Code

LinePlot.cxx

    #include <vtkVersion.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkRenderWindow.h>
    #include <vtkSmartPointer.h>
    #include <vtkChartXY.h>
    #include <vtkTable.h>
    #include <vtkPlot.h>
    #include <vtkFloatArray.h>
    #include <vtkContextView.h>
    #include <vtkContextScene.h>
    #include <vtkPen.h>

    int main(int, char *[])
    {
      // Create a table with some points in it
      vtkSmartPointer<vtkTable> table =
        vtkSmartPointer<vtkTable>::New();

      vtkSmartPointer<vtkFloatArray> arrX =
        vtkSmartPointer<vtkFloatArray>::New();
      arrX->SetName("X Axis");
      table->AddColumn(arrX);

      vtkSmartPointer<vtkFloatArray> arrC =
        vtkSmartPointer<vtkFloatArray>::New();
      arrC->SetName("Cosine");
      table->AddColumn(arrC);

      vtkSmartPointer<vtkFloatArray> arrS =
        vtkSmartPointer<vtkFloatArray>::New();
      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
      vtkSmartPointer<vtkContextView> view =
        vtkSmartPointer<vtkContextView>::New();
      view->GetRenderer()->SetBackground(1.0, 1.0, 1.0);

      // Add multiple line plots, setting the colors etc
      vtkSmartPointer<vtkChartXY> chart =
        vtkSmartPointer<vtkChartXY>::New();
      view->GetScene()->AddItem(chart);
      vtkPlot *line = chart->AddPlot(vtkChart::LINE);
    #if VTK_MAJOR_VERSION <= 5
      line->SetInput(table, 0, 1);
    #else
      line->SetInputData(table, 0, 1);
    #endif
      line->SetColor(0, 255, 0, 255);
      line->SetWidth(1.0);
      line = chart->AddPlot(vtkChart::LINE);
    #if VTK_MAJOR_VERSION <= 5
      line->SetInput(table, 0, 2);
    #else
      line->SetInputData(table, 0, 2);
    #endif
      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->GetInteractor()->Initialize();
      view->GetInteractor()->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(LinePlot)

    find_package(VTK REQUIRED)
    include(${VTK_USE_FILE})

    add_executable(LinePlot MACOSX_BUNDLE LinePlot.cxx )

    target_link_libraries(LinePlot ${VTK_LIBRARIES})

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