Section: 3.3 CDL

3.3 CDL

CDL (Common Data Language) is text notation for netCDF objects and data.

  netcdf example {   // example of CDL notation
  dimensions:
	  x = 3 ;
	  y = 8 ;
  variables:
	  float rh(x, y) ;
		  rh:units = "percent" ;
		  rh:long_name = "relative humidity" ;
  // global attributes
	  :title = "simple example, lacks some conventions" ;
  data:
   rh =
    2, 3, 5, 7, 11, 13, 17, 19,
    23, 29, 31, 37, 41, 43, 47, 53,
    59, 61, 67, 71, 73, 79, 83, 89 ;
  }

This example specifies a netCDF dataset with two dimensions, one variable, two variable attributes, one global attribute, and some data values for the variable.

This example has only one variable, but multiple variables of may be included in a netCDF file.
CDL comments follow "//" symbols. They are not part of netCDF data. To store comments about a variable or file, use a variable attribute or global attribute.
You can use the ncdump utility to get the CDL form of a binary netCDF file (more on this later).
You can use the ncgen utility to generate a binary netCDF file from CDL (more on this later).
This simple example neglects recommended best practices for netCDF data.
NcML is an XML-based notation similar to CDL for netCDF data

2007 Unidata NetCDF Workshop for Developers and Data Providers > The "Classic" NetCDF Data Model