[vtkusers] plotting bar chart with vtkBarChartActor and vtkXYPlotActor
David Doria
daviddoria+vtk at gmail.com
Fri Jan 8 19:08:44 EST 2010
On Thu, Jan 7, 2010 at 9:31 AM, michiel mentink
<michael.mentink at st-hughs.ox.ac.uk> wrote:
> oops. Forgot a small error. Correct now.
>
>
>
>
> #include <vtkActor.h>
> #include <vtkImageAccumulate.h>
> #include <vtkImageData.h>
> #include <vtkImageExtractComponents.h>
> #include <vtkJPEGReader.h>
> #include <vtkRenderer.h>
> #include <vtkRenderWindow.h>
> #include <vtkRenderWindowInteractor.h>
> #include <vtkSmartPointer.h>
> #include <vtkStdString.h>
> #include <vtkXYPlotActor.h>
> #include <vtkPointData.h>
>
> int main( int argc, char *argv[] )
> {
> // Handle the arguments
> if( argc < 2 )
> {
> vtkstd::cout << "Required arguments: filename.jpg, [optional ignore
> zero:] <y/n>" << vtkstd::endl;
> return EXIT_FAILURE;
> }
>
> int ignoreZero = 0;
> if( argc == 3 )
> {
> vtkStdString ignore = argv[2];
> cout << ignore << endl;
> if( ignore == "y" || ignore == "Y" )
> {
> ignoreZero = 1;
> }
> }
>
> // Read a jpeg image
> //
> vtkSmartPointer<vtkJPEGReader> reader =
> vtkSmartPointer<vtkJPEGReader>::New();
> if( !reader->CanReadFile( argv[1] ) )
> {
> vtkstd::cout << "Error: cannot read " << argv[1] << vtkstd::endl;
> return EXIT_FAILURE;
> }
> reader->SetFileName( argv[1] );
> reader->Update();
>
> int numComponents = reader->GetOutput()->GetNumberOfScalarComponents();
> if( numComponents > 3 )
> {
> vtkstd::cout << "Error: cannot process an image with " << numComponents
> << " components!" << vtkstd::endl;
> return EXIT_FAILURE;
> }
>
> // Create a vtkXYPlotActor
> //
> vtkSmartPointer<vtkXYPlotActor> plot =
> vtkSmartPointer<vtkXYPlotActor>::New();
> plot->ExchangeAxesOff();
> plot->SetLabelFormat( "%g" );
> plot->SetXTitle( "Level" );
> plot->SetYTitle( "Frequency" );
> plot->SetXValuesToValue();
>
> double xmax = 0.;
> double ymax = 0.;
>
> double colors[3][3] = {
> { 1, 0, 0 },
> { 0, 1, 0 },
> { 0, 0, 1 } };
>
> const char* labels[3] = {
> "Red", "Green", "Blue" };
>
> // Process the image, extracting and plotting a histogram for each
> component
> //
> //
>
> ofstream myfile;
> myfile.open ("histogram.txt");
> myfile << "Pixel intensities and their counts.\n";
>
> for( int i = 0; i < numComponents; ++i )
> {
> vtkSmartPointer<vtkImageExtractComponents> extract =
> vtkSmartPointer<vtkImageExtractComponents>::New();
> extract->SetInputConnection( reader->GetOutputPort() );
> extract->SetComponents( i );
> extract->Update();
>
> double range[2];
> extract->GetOutput()->GetScalarRange( range );
> vtkSmartPointer<vtkImageAccumulate> histogram =
> vtkSmartPointer<vtkImageAccumulate>::New();
> histogram->SetInputConnection( extract->GetOutputPort() );
> histogram->SetComponentExtent(
> 0,static_cast<int>(range[1])-static_cast<int>(range[0])-1,0,0,0,0 );
> histogram->SetComponentOrigin( range[0],0,0 );
> histogram->SetComponentSpacing( 1,0,0 );
> histogram->SetIgnoreZero( ignoreZero );
> histogram->Update();
>
> if( range[1] > xmax ) xmax = range[1];
> if( histogram->GetOutput()->GetScalarRange()[1] > ymax ) ymax =
> histogram->GetOutput()->GetScalarRange()[1];
>
> plot->AddInput( histogram->GetOutput() );
>
> if( numComponents > 1 )
> {
> plot->SetPlotColor(i,colors[i]);
> plot->SetPlotLabel(i,labels[i]);
> plot->LegendOn();
>
> myfile << "\n" << labels[i] << "\n\n";
> }
>
> unsigned int temp = (range[1]-1);
> unsigned int frequency[temp];
>
> std::cout<< "range: " << range[0] << " " << range[1] <<std::endl;
>
> unsigned int j;
>
> for(j=0;j<temp;j++){
> frequency[j]=0;
> frequency[j] =
> histogram->GetOutput()->GetPointData()->GetScalars()->GetTuple1(j);
> myfile << j << "\t" << frequency[j] << "\n";
> }
> }
>
> myfile.close();
>
> plot->SetXRange( 0, xmax );
> plot->SetYRange( 0, ymax );
>
> // Visualize the histogram(s)
> vtkSmartPointer<vtkRenderer> renderer =
> vtkSmartPointer<vtkRenderer>::New();
> renderer->AddActor(plot);
>
> vtkSmartPointer<vtkRenderWindow> renderWindow =
> vtkSmartPointer<vtkRenderWindow>::New();
> renderWindow->AddRenderer( renderer );
> renderWindow->SetSize(640, 480);
>
> vtkSmartPointer<vtkRenderWindowInteractor> interactor =
> vtkSmartPointer<vtkRenderWindowInteractor>::New();
> interactor->SetRenderWindow( renderWindow );
>
> // Initialize the event loop and then start it
> interactor->Initialize();
> interactor->Start();
>
>
> return EXIT_SUCCESS;
> }
>
>
> On Thu, Jan 7, 2010 at 2:29 PM, michiel mentink
> <michael.mentink at st-hughs.ox.ac.uk> wrote:
>>>
>>> Dear David,
>>
>> thank you for the example, there were some things that were different:
>> this bit in the code I certainly coded differently than in the example:
>>
>> histogram->SetComponentExtent(0, 4000, 0, 0, 0, 0);
>> histogram->SetComponentOrigin(0, 0, 0);
>> histogram->SetComponentSpacing(0.16, 0.16, 3.26); // component spacing:
>> depends on spacing of input volume
>>
>> I'm still a bit confused about the componentspacing.. as described above,
>> I assumed it to be dependent on the input volume,
>> but it is not???
>>
>> Anyway, I've extended your example a bit with writing the corresponding
>> intensity levels to a file, for opening in a spreadsheet program.
>> I'm not sure if it's too basic to put in the Examples section, but it
>> helped me and maybe someone else could benefit from it too.
>>
>>
>> Michael
>>
>>
>> #include <vtkActor.h>
>> #include <vtkImageAccumulate.h>
>> #include <vtkImageData.h>
>> #include <vtkImageExtractComponents.h>
>> #include <vtkJPEGReader.h>
>> #include <vtkRenderer.h>
>> #include <vtkRenderWindow.h>
>> #include <vtkRenderWindowInteractor.h>
>> #include <vtkSmartPointer.h>
>> #include <vtkStdString.h>
>> #include <vtkXYPlotActor.h>
>> #include <vtkPointData.h>
>>
>> int main( int argc, char *argv[] )
>> {
>> // Handle the arguments
>> if( argc < 2 )
>> {
>> vtkstd::cout << "Required arguments: filename.jpg, [optional ignore
>> zero:] <y/n>" << vtkstd::endl;
>> return EXIT_FAILURE;
>> }
>>
>> int ignoreZero = 0;
>> if( argc == 3 )
>> {
>> vtkStdString ignore = argv[2];
>> cout << ignore << endl;
>> if( ignore == "y" || ignore == "Y" )
>> {
>> ignoreZero = 1;
>> }
>> }
>>
>> // Read a jpeg image
>> //
>> vtkSmartPointer<vtkJPEGReader> reader =
>> vtkSmartPointer<vtkJPEGReader>::New();
>> if( !reader->CanReadFile( argv[1] ) )
>> {
>> vtkstd::cout << "Error: cannot read " << argv[1] << vtkstd::endl;
>> return EXIT_FAILURE;
>> }
>> reader->SetFileName( argv[1] );
>> reader->Update();
>>
>> int numComponents = reader->GetOutput()->GetNumberOfScalarComponents();
>> if( numComponents > 3 )
>> {
>> vtkstd::cout << "Error: cannot process an image with " <<
>> numComponents << " components!" << vtkstd::endl;
>> return EXIT_FAILURE;
>> }
>>
>> // Create a vtkXYPlotActor
>> //
>> vtkSmartPointer<vtkXYPlotActor> plot =
>> vtkSmartPointer<vtkXYPlotActor>::New();
>> plot->ExchangeAxesOff();
>> plot->SetLabelFormat( "%g" );
>> plot->SetXTitle( "Level" );
>> plot->SetYTitle( "Frequency" );
>> plot->SetXValuesToValue();
>>
>> double xmax = 0.;
>> double ymax = 0.;
>>
>> double colors[3][3] = {
>> { 1, 0, 0 },
>> { 0, 1, 0 },
>> { 0, 0, 1 } };
>>
>> const char* labels[3] = {
>> "Red", "Green", "Blue" };
>>
>> // Process the image, extracting and plotting a histogram for each
>> component
>> //
>> //
>>
>> ofstream myfile;
>> myfile.open ("histogram.txt");
>> myfile << "Pixel intensities and their counts.\n";
>>
>> for( int i = 0; i < numComponents; ++i )
>> {
>> vtkSmartPointer<vtkImageExtractComponents> extract =
>> vtkSmartPointer<vtkImageExtractComponents>::New();
>> extract->SetInputConnection( reader->GetOutputPort() );
>> extract->SetComponents( i );
>> extract->Update();
>>
>> double range[2];
>> extract->GetOutput()->GetScalarRange( range );
>> vtkSmartPointer<vtkImageAccumulate> histogram =
>> vtkSmartPointer<vtkImageAccumulate>::New();
>> histogram->SetInputConnection( extract->GetOutputPort() );
>> histogram->SetComponentExtent(
>> 0,static_cast<int>(range[1])-static_cast<int>(range[0])-1,0,0,0,0 );
>> histogram->SetComponentOrigin( range[0],0,0 );
>> histogram->SetComponentSpacing( 1,0,0 );
>> histogram->SetIgnoreZero( ignoreZero );
>> histogram->Update();
>>
>> if( range[1] > xmax ) xmax = range[1];
>> if( histogram->GetOutput()->GetScalarRange()[1] > ymax ) ymax =
>> histogram->GetOutput()->GetScalarRange()[1];
>>
>> plot->AddInput( histogram->GetOutput() );
>>
>> if( numComponents > 1 )
>> {
>> plot->SetPlotColor(i,colors[i]);
>> plot->SetPlotLabel(i,labels[i]);
>> plot->LegendOn();
>>
>> myfile << "\n" << labels[i] << "\n\n";
>> }
>>
>> unsigned int temp = (range[1]-1);
>> unsigned int frequency[numLevels];
>>
>> std::cout<< "range: " << range[0] << " " << range[1] <<std::endl;
>>
>> unsigned int j;
>>
>> for(j=0;j<temp;j++){
>> frequency[j]=0;
>> frequency[j] =
>> histogram->GetOutput()->GetPointData()->GetScalars()->GetTuple1(j);
>> myfile << j << "\t" << frequency[j] << "\n";
>> }
>> }
>>
>> myfile.close();
>>
>> plot->SetXRange( 0, xmax );
>> plot->SetYRange( 0, ymax );
>>
>> // Visualize the histogram(s)
>> vtkSmartPointer<vtkRenderer> renderer =
>> vtkSmartPointer<vtkRenderer>::New();
>> renderer->AddActor(plot);
>>
>> vtkSmartPointer<vtkRenderWindow> renderWindow =
>> vtkSmartPointer<vtkRenderWindow>::New();
>> renderWindow->AddRenderer( renderer );
>> renderWindow->SetSize(640, 480);
>>
>> vtkSmartPointer<vtkRenderWindowInteractor> interactor =
>> vtkSmartPointer<vtkRenderWindowInteractor>::New();
>> interactor->SetRenderWindow( renderWindow );
>>
>> // Initialize the event loop and then start it
>> interactor->Initialize();
>> interactor->Start();
>>
>>
>> return EXIT_SUCCESS;
>> }
>>
>>
>>
>>>
>>> I reorganized the code a little bit, changed the input to a jpeg, and
>>> posted an example in the "broken" section:
>>> http://www.cmake.org/Wiki/VTK/Examples/Histogram
>>>
>>> Maybe this will double your chances of someone seeing it and figuring
>>> out what is wrong :)
>>>
>>> Thanks,
>>>
>>> David
Michiel,
Dean has kindly been working on some examples:
http://www.cmake.org/Wiki/VTK/Examples/Histogram
http://www.cmake.org/Wiki/VTK/Examples/HistogramBarChart
Have you done something that is not present in one of these? If so,
can you explain the difference and we'll work together to create a
third example.
Thanks,
David
More information about the vtkusers
mailing list