BoxChart
vtk-examples/Cxx/Plotting/BoxChart
Description¶
This example demonstrates how to generate a box plot.
The example uses data from the Michelson Morley experiment. Compare the wiki example output with the Wikipedia results
Warning
The ChartBox expects an input table with exactly 5 rows per column. The 5 rows are minimum, 1st quartile, median, 3rd quartile and maximum. vtkComputeQuartiles is used to create a valid input table from the original data.
Question
If you have a question about this example, please use the VTK Discourse Forum
Code¶
BoxChart.cxx
#include <vtkSmartPointer.h>
#include <vtkChartBox.h>
#include <vtkStatisticsAlgorithm.h>
#include <vtkComputeQuartiles.h>
#include <vtkContextScene.h>
#include <vtkContextView.h>
#include <vtkIntArray.h>
#include <vtkLookupTable.h>
#include <vtkPlotBox.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkStringArray.h>
#include <vtkTable.h>
#include <vtkAxis.h>
#include <vtkTextProperty.h>
//----------------------------------------------------------------------------
int main(int , char* [])
{
// Set up a 2D scene, add an XY chart to it
vtkSmartPointer<vtkContextView> view =
vtkSmartPointer<vtkContextView>::New();
view->GetRenderWindow()->SetSize(400, 400);
view->GetRenderWindow()->SetMultiSamples(0);
vtkSmartPointer<vtkChartBox> chart =
vtkSmartPointer<vtkChartBox>::New();
view->GetScene()->AddItem(chart);
// Creates a vtkPlotBox input table
int numParam = 5;
vtkSmartPointer<vtkTable> inputBoxPlotTable =
vtkSmartPointer<vtkTable>::New();
for (int i = 0; i < numParam; i++)
{
char num[10];
sprintf(num, "Run %d", i + 1);
vtkSmartPointer<vtkIntArray> arrIndex =
vtkSmartPointer<vtkIntArray>::New();
arrIndex->SetName(num);
inputBoxPlotTable->AddColumn(arrIndex);
}
inputBoxPlotTable->SetNumberOfRows(20);
double values[20][5] =
{
{850, 960, 880, 890, 890},
{740, 940, 880, 810, 840},
{900, 960, 880, 810, 780},
{1070, 940, 860, 820, 810},
{930, 880, 720, 800, 760},
{850, 800, 720, 770, 810},
{950, 850, 620, 760, 790},
{980, 880, 860, 740, 810},
{980, 900, 970, 750, 820},
{880, 840, 950, 760, 850},
{1000, 830, 880, 910, 870},
{980, 790, 910, 920, 870},
{930, 810, 850, 890, 810},
{650, 880, 870, 860, 740},
{760, 880, 840, 880, 810},
{810, 830, 840, 720, 940},
{1000, 800, 850, 840, 950},
{1000, 790, 840, 850, 800},
{960, 760, 840, 850, 810},
{960, 800, 840, 780, 870}
};
for (int j = 0; j < 20; ++j)
{
for (int i = 0; i < 5; ++i)
{
inputBoxPlotTable->SetValue(j, i, values[j][i]);
}
}
vtkSmartPointer<vtkComputeQuartiles> quartiles =
vtkSmartPointer<vtkComputeQuartiles>::New();
quartiles->SetInputData(vtkStatisticsAlgorithm::INPUT_DATA, inputBoxPlotTable);
quartiles->Update();
vtkTable *outTable = quartiles->GetOutput();
vtkSmartPointer<vtkLookupTable> lookup =
vtkSmartPointer<vtkLookupTable>::New();
lookup->SetNumberOfColors(5);
lookup->SetRange(0, 4);
lookup->Build();
chart->GetPlot(0)->SetInputData(outTable);
chart->SetShowLegend(true);
chart->SetColumnVisibilityAll(true);
chart->SetTitle("Michelson-Morley experiment");
chart->GetTitleProperties()->SetFontSize(16);
chart->GetYAxis()->SetTitle("Speed of Light (km/s - 299000)");
// Set the labels
vtkSmartPointer<vtkStringArray> labels =
vtkSmartPointer<vtkStringArray>::New();
labels->SetNumberOfValues(5);
labels->SetValue(0, "Run 1");
labels->SetValue(1, "Run 2");
labels->SetValue(2, "Run 3");
labels->SetValue(3, "Run 4");
labels->SetValue(4, "Run 5");
chart->GetPlot(0)->SetLabels(labels);
// Render the scene
view->GetRenderWindow()->SetMultiSamples(0);
view->GetRenderer()->SetBackground(.8, .8, .8);
view->GetInteractor()->Initialize();
view->Render();
view->GetInteractor()->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt¶
cmake_minimum_required(VERSION 3.3 FATAL_ERROR)
project(BoxChart)
find_package(VTK COMPONENTS
vtkChartsCore
vtkCommonCore
vtkCommonDataModel
vtkFiltersStatistics
vtkInteractionStyle
vtkRenderingContext2D
vtkRenderingContextOpenGL2
vtkRenderingCore
vtkRenderingFreeType
vtkRenderingGL2PSOpenGL2
vtkRenderingOpenGL2
vtkViewsContext2D
QUIET
)
if (NOT VTK_FOUND)
message("Skipping BoxChart: ${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(BoxChart MACOSX_BUNDLE BoxChart.cxx )
target_link_libraries(BoxChart PRIVATE ${VTK_LIBRARIES})
else ()
# include all components
add_executable(BoxChart MACOSX_BUNDLE BoxChart.cxx )
target_link_libraries(BoxChart PRIVATE ${VTK_LIBRARIES})
# vtk_module_autoinit is needed
vtk_module_autoinit(
TARGETS BoxChart
MODULES ${VTK_LIBRARIES}
)
endif ()
Download and Build BoxChart¶
Click here to download BoxChart and its CMakeLists.txt file. Once the tarball BoxChart.tar has been downloaded and extracted,
cd BoxChart/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:
./BoxChart
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.