VTK - How to use vtkNetCDFCFReader to read an array or variable array at specific time frame

问题

Im trying to load an array at a specific time frame (for example if it has 50 frames or time units then get an array corresponding to the 2nd time frame) from netCDF files (.nc). Im currently using vtkNetCDFCFReader and getting the data array "vwnd" from the 1st time frame like this:

vtkSmartPointer<vtkNetCDFCFReader> reader = vtkSmartPointer<vtkNetCDFCFReader>::New();
reader->SetFileName(path.c_str());
reader->UpdateMetaData();

vtkSmartPointer<vtkStructuredGridGeometryFilter> geometryFilter = vtkSmartPointer<vtkStructuredGridGeometryFilter>::New();
geometryFilter->SetInputConnection(reader->GetOutputPort());
geometryFilter->Update();

vtkSmartPointer<vtkPolyData> ncPolydata = vtkSmartPointer<vtkPolyData>::New();
ncPolydata = geometryFilter->GetOutput();
vtkSmartPointer<vtkDataArray> dataArray = ncPolydata->GetCellData()->GetArray("vwnd");

Variable Arrays are : lat, lon, time, vwnd (vwnd has dimensions (lat,lon)). Im also interested in getting arrays for lat and lon. Any help would be appreciated.

Thanks in advance

回答1:

As the dimension of lat/lon is different from vwnd, you will need 2 vtknetCDFreaders to read in data with different dimensions. Just remember to set the dimension after creating the reader.

For example in C++:

vtknetCDFReader* reader = vtknetCDFReader::New();
reader->SetFileName(fileName.c_str());
reader->UpdateMetaData();
//here you specify the dimension of the reader
reader->SetDimension(dim);
reader->SetVariableArrayStatus("lat",1)
reader->SetVariableArrayStatus("lon",1)
reader->Update();

If you are doing it correctly, you could read in any arrays and store it into vtkDataArray.

If you want to read in the vwnd data in the second time step, just skip the first lat*lon values.

来源：https://stackoverflow.com/questions/43298315/vtk-how-to-use-vtknetcdfcfreader-to-read-an-array-or-variable-array-at-specifi

标签

vtk

netcdf