# ConstructTable

VTKExamples/Cxx/Utilities/ConstructTable

### Description¶

This example creates a 3x3 table. The columns MUST be added first - if you attempt to call AddRow type functions, they will not do anything (or produce errors) because the table still has 0 columns until you tell it otherwise. This example adds 3 empty columns to the table, then goes back and fills them in.

Warning: the table does not copy the data, so if you add the SAME column to the table each time, i.e. vtkSmartPointer vtkVariantArray> col = vtkSmartPointer vtkVariantArray>::New();

If you modify one of the entries in the table with Table->SetValue ( r,c, vtkVariant ( counter ) ); after they have all been set to the same column, the rth entry in EVERY column will be changed.

### Code¶

ConstructTable.cxx

#include <vtkTable.h>
#include <vtkVariant.h>
#include <vtkVariantArray.h>
#include <vtkSmartPointer.h>

int main(int, char *[])
{
//construct an empty table
vtkSmartPointer<vtkTable> table =
vtkSmartPointer<vtkTable>::New();

for ( unsigned int i = 0; i < 3; i++ )
{
vtkSmartPointer<vtkVariantArray> col =
vtkSmartPointer<vtkVariantArray>::New();

col->InsertNextValue ( vtkVariant ( 0.0 ) );
col->InsertNextValue ( vtkVariant ( 0.0 ) );
col->InsertNextValue ( vtkVariant ( 0.0 ) );
}

//fill the table with values
unsigned int counter = 0;
for(vtkIdType r = 0; r < table->GetNumberOfRows(); r++ )
{
for(vtkIdType c = 0; c < table->GetNumberOfColumns(); c++ )
{
table->SetValue ( r,c, vtkVariant ( counter ) );
counter++;
}
}

std::cout << "NumRows: " << table->GetNumberOfRows() << std::endl;
std::cout << "NumCols: " << table->GetNumberOfColumns() << std::endl;

//display the table
table->Dump ( 3 );

//access elements of the table
for(vtkIdType r = 0; r < table->GetNumberOfRows(); r++ )
{
for(vtkIdType c = 0; c < table->GetNumberOfColumns(); c++ )
{
vtkVariant v = table->GetValue( r,c);
std::cout << "(r,c) = (" << r << "," << c << ") = " << v << std::endl;
}
}

return EXIT_SUCCESS;
}


### CMakeLists.txt¶

cmake_minimum_required(VERSION 2.8)

PROJECT(ConstructTable)

find_package(VTK REQUIRED)
include(${VTK_USE_FILE}) add_executable(ConstructTable MACOSX_BUNDLE ConstructTable.cxx ) target_link_libraries(ConstructTable${VTK_LIBRARIES})


cd ConstructTable/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:

./ConstructTable


WINDOWS USERS

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