rmnlib is a library of functions for numerical weather prediction used primarily by Environment and and Climate Change Canada.

Its main components are Standard RPN files and the EZ interpolator.

Documentation

• Functions reference accessible from the Internet
• More complete documentation on CMC Wiki

Getting the code

The project is hosted at https://gitlab.science.gc.ca/RPN-SI/librmn The code is available via Git at the following locations:

• On ECCC network: [email protected]:RPN-SI/librmn.git
• For users outside ECCC: https://github.com/ECCC-ASTD-MRD/librmn.git

cmake_rpn is included as a git submodule. Please clone with the --recursive option or run git submodule update --init --recursive in the git repo after having cloned.

Installation instructions

Create a directory for compilation

mkdir $build_dir_path
cd $build_dir_path

Build setup

Options to configure compilation must be added with the -D prefix when calling the cmake command.

CMAKE_BUILD_TYPE : (Release|RelWithDebInfo|Debug) Compilation mode. Default: RelWithDebInfo

CMAKE_INSTALL_PREFIX : Directory path for installation (make install)

COMPILER_SUITE : (gnu|intel|xl|nvhpc|...) Compiler suite to be used. On ECCC systems, the compiler loaded will be used. If the ECCC-specific environment variables are not not found, the default is gnu.

WITH_OMPI : (yes|no) Indicates whether OpenMP/MPI support is enabled. Default: yes

Compilation example

cmake \
    -DCMAKE_INSTALL_PREFIX=$install_dir_path \
    -DWITH_OMPI=no \
    $src_dir_path
make -j $a_resonable_number
make install

Compilation in ECCC environment

CMake scripts from cmake_rpn will automatically detect the compiler loaded via the EC_ARCH environment variable. It is therefore not necessary to explicitly specify the compiler suite to use (-DCOMPILER_SUITE=...).
However, you must load the desired compiler before performing the build configuration.

Source the right file from the ECCI_ENV variable, depending on the desired architecture. This will load the specified compiler, set the ECCI_DATA_DIR variable for the test datasets, and set the EC_CMAKE_MODULE_PATH variable for the cmake_rpn modules.

• Example for PPP5:

. $ECCI_ENV/latest/ppp5/inteloneapi-2022.1.2.sh

• Example for CMC network and gnu 11.4.0:

. $ECCI_ENV/latest/ubuntu-22.04-amd-64/gnu.sh

Since the default version of CMake available on ECCC systems is probably too old, you need to load a version newer than 3.20. For example: . ssmuse-sh -d main/opt/cmake/cmake-3.21.1.

Example of compiling the dev branch on a system outside ECCC:

git clone -b dev https://github.com/ECCC-ASTD-MRD/librmn.git
cd librmn
git submodule update --init --recursive
cd ..
mkdir librmn_build
cd librmn_build
cmake ../librmn -DCMAKE_INSTALL_PREFIX=~/opt/
make -j4 install

Documentation

A doc target is created by cmake to generate documentation. This, however, requires Doxygen and graphviz.

make doc

Change of compiler

Since the library of functions contains a Fortran module, it must use the same compiler that produced the library for the client applications.

So, you have to clean the compilation directory and re-execute the compilation instructions specifying a different installation directory (-DCMAKE_INSTALL_PREFIX=$install_dir_path).

Example of use in a client application

We have developed a very simple example of an application using librmn. It can be used as a reference to build a CMake project that uses librmn.

It can be consulted at the following addresses:

• https://gitlab.science.gc.ca/RPN-SI/librmn-client-example (On ECCC network)
• https://github.com/ECCC-ASTD-MRD/librmn-client-example (Public)

The static version of the library will be the one used by default when searching for the rmn package, unless specified. Examples:

find_package(rmn [version] REQUIRED)
find_package(rmn [version] REQUIRED COMPONENTS shared)