Self-baked NetCDF Fortran Library

The Self-baked NetCDF Fortran library is a light weighted NetCDF C Library wrapper and an intermediate interface written in modern Fortran. This project is designed as a temporary workaround of the current fpm/NetCDF incoherence (see fpm discussion, fpm issue, discussion on discourse, suggestions from Richard Weed). Thus, you are welcome to use and contribute to this project, but use at your own risk.

The major difference between this library and most of the other implementations (for example nc4fortran) is that this library is built on top of NetCDF C library directly. If you are intereseted in using this project with fpm, add the following lines to your fpm.toml

[dependencies]
self-baked-nf = {git="https://github.com/han190/Self-Baked-Fortran-NetCDF"}
[build]
link = "netcdf"

Examples of the intermediate interface

Write to a NetCDF file

Write a single variable to a NetCDF file

program main

use module_netcdf
implicit none

integer, parameter :: nx = 3, ny = 4
character(len=*), parameter :: filename = "simple_xy.nc"
type(netcdf_variable) :: var
real :: raw(nx, ny)

! Fill an array with random numbers.
call random_number(raw)

! Construct a data array and write to a NetCDF file.
var = data_array(raw, "data", dims=["x".dim.nx, "y".dim.ny])
call to_netcdf(var, filename)

end program main

Write multiple variables to a NetCDF file

program main

use module_netcdf
implicit none

integer, parameter :: nx = 4, ny = 3, nz = 2, nt = 1
type(netcdf_variable) :: geopt, temp, slp
real :: geopt_raw(nx, ny, nz)
integer :: temp_raw(nx, ny, nt)
double precision :: slp_raw(nx, ny)
real :: nan

nan = ieee_value(0.0, ieee_quiet_nan)
call random_number(geopt_raw)
geopt = data_array(geopt_raw, "geopt", &
  & dims=["latitude".dim.nx, "longitude".dim.ny, "level".dim.nz], &
  & atts=["long_name".att."geopotenail", "_FillValue".att.nan])

temp_raw = 1
temp = data_array(temp_raw, "temp", &
  & dims=["latitude".dim.nx, "longitude".dim.ny, "time".dim.nt], &
  & atts=["long_name".att."temperature", "add_offset".att.-273.15, "scale_factor".att.1.0])

call random_number(slp_raw)
slp = data_array(slp_raw, "slp", &
  & dims=["latitude".dim.nx, "longitude".dim.ny], &
  & atts=["long_name".att."sea level pressure", "missing_value".att.-2147483647])

print "(*(dt))", geopt, temp, slp
call to_netcdf([geopt, temp, slp], "multiple_vars.nc")
end program main

Read from a NetCDF file

Read a single variable from a NetCDF file

program main

use module_netcdf
implicit none

character(len=*), parameter :: filename = "simple_xy.nc"
type(netcdf_variable) :: var
real, pointer :: raw(:, :) => null()

! Read from NetCDF and extract data
var = from_netcdf(filename, "data")
call extract(var, raw)
end program main

Miscellaneous

To count the LOC for this project

cloc --force-lang-def=./misc/language_definitions.txt --exclude-dir=backups,src,doc,build .

To generate and compile source code

./compile