Fortran/Documenting Fortran

FORD - FORtran Documenter

A great program for documenting fortran source code is FORD.

See the github page for instructions on installing, and usage of FORD: github.com.

Documenting Fortran using Doxygen

Documentation can be created right from source code using Doxygen.

The commandline program doxygen creates the documentation using configuration files. The gui program doxygen-wizard helps creating those files.

Overview

The source code needs to be documented using special comment syntax:  !>, and  !!.

One should always set OPTIMIZE_FOR_FORTRAN = YES within the configuration file.

Doxygen commands are usually ended by an empty comment line or a new doxygen command.

Note that support for Fortran is rather bad in doxygen. Even simple constructs such as public/private statements inside of types are not supported (see here github.com).

LaTeX

One can also include LaTeX code within the documentation. Doxygen's website gives detailed information.

Examples

subroutine

!> @brief inserts a value into an ordered array
!!
!! An array "list" consisting of n ascending ordered values. The method insert a
!! "new_entry" into the array.
!! hint: use cshift and eo-shift
!!
!! @param[in,out]   list    a real array, size: max_size
!! @param[in]       n       current values in the array
!! @param[in]       max_size    size if the array
!! @param[in]       new_entry   the value to insert
subroutine insert(list, n, max_size, new_entry)
    implicit none
    real, dimension (:), intent (inout) :: list
    integer, intent (in) :: n, max_size
    real, intent (in) :: new_entry

    ! code ........
end subroutine insert

function

!> @brief calcs the angle between two given vectors
!!
!! using the standard formula:
!!  \f$\cos \theta = \frac{ \vec v \cdot \vec w}{\abs{v}\abs{w}}\f$.
!!
!! @param[in]   \f$v,w\f$   real vectors
!! @return  a real value describing the angle. 0 if \f$\abs v\f$ or \f$\abs w\f$ below a
!!          threshold.
pure function calc_angle(v, w) result (theta)
  implicit none
  real, dimension (:), intent (in) :: v, w
  real :: theta

  ! code .......
end function calc_angle

Troubleshooting

Empty documentation

If the documentation is just an empty page then one can try setting EXTRACT_ALL = YES.