AreaPlot
vtk-examples/Cxx/Plotting/AreaPlot
Description¶
This example illustrates vtkPlotArea, which draws a filled region between two curves. The example uses a valid mask to select the values to define the region to be plotted.
The example also shows how to control the size and colors of the plot's components.
Question
If you have a question about this example, please use the VTK Discourse Forum
Code¶
AreaPlot.cxx
#include <vtkNew.h>
#include <vtkPlotArea.h>
#include <vtkNamedColors.h>
#include <vtkAxis.h>
#include <vtkBrush.h>
#include <vtkCharArray.h>
#include <vtkChartXY.h>
#include <vtkContextScene.h>
#include <vtkContextView.h>
#include <vtkFloatArray.h>
#include <vtkNew.h>
#include <vtkPlot.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkTable.h>
#include <vtkTextProperty.h>
#include <algorithm>
//----------------------------------------------------------------------------
int main(int, char*[])
{
vtkNew<vtkNamedColors> colors;
// Set up a 2D scene, add an XY chart to it
vtkNew<vtkContextView> view;
view->GetRenderWindow()->SetSize(640, 480);
view->GetRenderWindow()->SetWindowName("AreaPlot");
vtkNew<vtkChartXY> chart;
chart->SetTitle("Area Plot");
chart->GetTitleProperties()->SetFontSize(36);
chart->GetTitleProperties()->SetColor(colors->GetColor3d("Banana").GetData());
chart->GetAxis(0)->GetTitleProperties()->SetFontSize(24);
chart->GetAxis(0)->GetTitleProperties()->SetColor(
colors->GetColor3d("orange").GetData());
chart->GetAxis(0)->GetLabelProperties()->SetColor(
colors->GetColor3d("beige").GetData());
chart->GetAxis(0)->GetLabelProperties()->SetFontSize(18);
chart->GetAxis(1)->GetTitleProperties()->SetFontSize(24);
chart->GetAxis(1)->GetTitleProperties()->SetColor(
colors->GetColor3d("orange").GetData());
chart->GetAxis(1)->GetLabelProperties()->SetColor(
colors->GetColor3d("beige").GetData());
chart->GetAxis(1)->GetLabelProperties()->SetFontSize(18);
view->GetScene()->AddItem(chart);
// 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);
vtkNew<vtkFloatArray> arrS2;
arrS2->SetName("Sine2");
table->AddColumn(arrS2);
vtkNew<vtkFloatArray> arrS3;
arrS3->SetName("Sine3");
table->AddColumn(arrS3);
vtkNew<vtkFloatArray> arr1;
arr1->SetName("One");
table->AddColumn(arr1);
vtkNew<vtkCharArray> validMask;
validMask->SetName("ValidMask");
table->AddColumn(validMask);
// Test charting with a few more points...
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 + 0.01);
table->SetValue(i, 1, cos(i * inc) + 0.01);
table->SetValue(i, 2, sin(i * inc) + 0.01);
table->SetValue(i, 3, sin(i * inc) + 0.5);
table->SetValue(i, 4, sin(i * inc) * sin(i * inc) + 0.01);
table->SetValue(i, 5, 1.0);
validMask->SetValue(i, (i > 30 && i < 40) ? 0 : 1);
}
// Add multiple line plots, setting the colors etc
vtkColor3d color3d = colors->GetColor3d("tomato");
vtkPlotArea* area =
dynamic_cast<vtkPlotArea*>(chart->AddPlot(vtkChart::AREA));
area->SetInputData(table);
area->SetInputArray(0, "X Axis");
area->SetInputArray(1, "Sine");
area->SetInputArray(2, "Sine2");
area->SetValidPointMaskName("ValidMask");
area->GetBrush()->SetColorF(color3d.GetRed(), color3d.GetGreen(),
color3d.GetBlue(), .6);
chart->GetAxis(vtkAxis::LEFT)->SetLogScale(true);
// Render the scene and compare the image to a reference image
view->GetRenderer()->SetBackground(colors->GetColor3d("SlateGray").GetData());
view->GetRenderWindow()->SetMultiSamples(0);
view->GetRenderWindow()->Render();
view->GetInteractor()->Initialize();
view->GetInteractor()->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt¶
cmake_minimum_required(VERSION 3.12 FATAL_ERROR)
project(AreaPlot)
find_package(VTK COMPONENTS
vtkChartsCore
vtkCommonColor
vtkCommonCore
vtkCommonDataModel
vtkInteractionStyle
vtkRenderingContext2D
vtkRenderingContextOpenGL2
vtkRenderingCore
vtkRenderingFreeType
vtkRenderingGL2PSOpenGL2
vtkRenderingOpenGL2
vtkViewsContext2D
QUIET
)
if (NOT VTK_FOUND)
message("Skipping AreaPlot: ${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(AreaPlot MACOSX_BUNDLE AreaPlot.cxx )
target_link_libraries(AreaPlot PRIVATE ${VTK_LIBRARIES})
else()
# Prevent a "command line is too long" failure in Windows.
set(CMAKE_NINJA_FORCE_RESPONSE_FILE "ON" CACHE BOOL "Force Ninja to use response files.")
add_executable(AreaPlot MACOSX_BUNDLE AreaPlot.cxx )
target_link_libraries(AreaPlot PRIVATE ${VTK_LIBRARIES})
# vtk_module_autoinit is needed
vtk_module_autoinit(
TARGETS AreaPlot
MODULES ${VTK_LIBRARIES}
)
endif()
Download and Build AreaPlot¶
Click here to download AreaPlot and its CMakeLists.txt file. Once the tarball AreaPlot.tar has been downloaded and extracted,
cd AreaPlot/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:
./AreaPlot
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.