f_user_types.f90 File Reference

Demonstrates NetCDF-4 user-defined types (Fortran) More...

Functions/Subroutines
program	f_user_types
subroutine	define_and_test_opaque (ncid)

Detailed Description

Demonstrates NetCDF-4 user-defined types (Fortran)

Fortran equivalent of user_types.c, demonstrating NetCDF-4 user-defined types using the Fortran 90 NetCDF API. Note: Fortran support for compound types is limited compared to C, so this focuses on enum, vlen, and opaque types.

Learning Objectives:

• Understand Fortran limitations with compound types
• Work with enum types in Fortran (nf90_def_enum)
• Use vlen types for variable-length arrays
• Handle opaque types for binary data

Fortran User Type Limitations:

• Compound types have limited Fortran support
• Enum, vlen, and opaque types fully supported
• Type definitions similar to C API

Prerequisites:

• f_simple_nc4.f90 - NetCDF-4 format basics
• user_types.c - C equivalent (more complete)

Related Examples:

• user_types.c - C equivalent (full compound type support)
• f_compression.f90 - Compression with user types

Compilation:

gfortran -o f_user_types f_user_types.f90 -lnetcdff -lnetcdf

Author

Edward Hartnett, Intelligent Data Design, Inc.

Date

2026

Function/Subroutine Documentation

define_and_test_opaque()

subroutine f_user_types::define_and_test_opaque

(

integer, intent(in)

ncid

)

f_user_types()

program f_user_types