AlphaFrequency
vtk-examples/Cxx/Visualization/AlphaFrequency
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Code¶
AlphaFrequency.cxx
//
// Create bar charts of frequency of letters.
//
#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkLinearExtrusionFilter.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkVectorText.h>
#include <vector>
int main(int argc, char* argv[])
{
vtkNew<vtkNamedColors> colors;
std::vector<vtkSmartPointer<vtkVectorText>> letters;
std::vector<vtkSmartPointer<vtkLinearExtrusionFilter>> extrude;
std::vector<vtkSmartPointer<vtkPolyDataMapper>> mappers;
std::vector<vtkSmartPointer<vtkActor>> actors;
char filename[512];
char text[2];
static char alphabet[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
int i, j, freq[26], maxFreq;
float x, y;
FILE* fPtr;
int c;
//
// count the letters
//
if ((argc == 1) || ((argc == 2) && !(strcmp("-S", argv[1]))))
{
cerr << "Please provide filename: " << argv[0] << " filename\n";
strcpy(filename, "./Makefile");
cerr << "Using the file " << filename << " as input\n";
}
else
{
strcpy(filename, argv[1]);
}
if ((fPtr = fopen(filename, "r")) == NULL)
{
cerr << "Cannot open file: " << filename << "\n";
exit(1);
}
for (i = 0; i < 26; i++) freq[i] = 0;
while ((c = fgetc(fPtr)) != EOF)
{
if (isalpha(c))
{
c = tolower(c);
freq[c - 97]++;
}
}
for (maxFreq = 0, i = 0; i < 26; i++)
if (freq[i] > maxFreq)
maxFreq = freq[i];
//
// graphics stuff
//
vtkNew<vtkRenderer> ren;
vtkNew<vtkRenderWindow> renWin;
renWin->AddRenderer(ren);
vtkNew<vtkRenderWindowInteractor> iren;
iren->SetRenderWindow(renWin);
//
// Setup letters
//
text[1] = '\0';
for (i = 0; i < 26; i++)
{
text[0] = alphabet[i];
letters.push_back(vtkSmartPointer<vtkVectorText>::New());
letters[i]->SetText(text);
extrude.push_back(vtkSmartPointer<vtkLinearExtrusionFilter>::New());
extrude[i]->SetInputConnection(letters[i]->GetOutputPort());
extrude[i]->SetExtrusionType(VTK_VECTOR_EXTRUSION);
extrude[i]->SetVector(0, 0, 1.0);
extrude[i]->SetScaleFactor((double)freq[i] / maxFreq * 2.50);
mappers.push_back(vtkSmartPointer<vtkPolyDataMapper>::New());
mappers[i]->SetInputConnection(extrude[i]->GetOutputPort());
mappers[i]->ScalarVisibilityOff();
actors.push_back(vtkSmartPointer<vtkActor>::New());
actors[i]->SetMapper(mappers[i]);
actors[i]->GetProperty()->SetColor(colors->GetColor3d("Peacock").GetData());
if (freq[i] <= 0)
{
actors[i]->VisibilityOff();
}
ren->AddActor(actors[i]);
}
//
// Position actors
//
for (y = 0.0, j = 0; j < 2; j++, y += (-3.0))
{
for (x = 0.0, i = 0; i < 13; i++, x += 1.5)
{
actors[j * 13 + i]->SetPosition(x, y, 0.0);
}
}
ren->ResetCamera();
ren->SetBackground(colors->GetColor3d("Silver").GetData());
ren->GetActiveCamera()->Elevation(30.0);
ren->GetActiveCamera()->Azimuth(-30.0);
ren->GetActiveCamera()->Dolly(1.25);
ren->ResetCameraClippingRange();
renWin->SetSize(640, 480);
renWin->SetWindowName("AlphaFrequency");
// interact with data
renWin->Render();
iren->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt¶
cmake_minimum_required(VERSION 3.12 FATAL_ERROR)
project(AlphaFrequency)
find_package(VTK COMPONENTS
)
if (NOT VTK_FOUND)
message(FATAL_ERROR "AlphaFrequency: Unable to find the VTK build folder.")
endif()
# 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(AlphaFrequency MACOSX_BUNDLE AlphaFrequency.cxx )
target_link_libraries(AlphaFrequency PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
TARGETS AlphaFrequency
MODULES ${VTK_LIBRARIES}
)
Download and Build AlphaFrequency¶
Click here to download AlphaFrequency and its CMakeLists.txt file. Once the tarball AlphaFrequency.tar has been downloaded and extracted,
cd AlphaFrequency/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:
./AlphaFrequency
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.