Reading NetCDF and HDF Files with grads
Data files in the NetCDF and HDF file formats are called self-describing files (SDF) because the data and metadata are packaged together in the same file. grads can read data NetCDF and HDF formatted files, as long as the data are on a regular grid. The HDF format is very general; the grads interface is limited to gridded data sets that fit into the internal 5-D lon/lat/lev/time/ensemble grid space. grads handles HDF4 Scientific Data Sets and (as of version 2.0.a7) some HDF5 files. In order to read the data in SDFs, grads needs a certain amount of metadata in order to place the data in the internal grid space. There are three ways to do this: