Getting started » Downloading and building » transi

What is transi?

transi contains a C interface and Fortran implementation of the IFS spectral transforms library trans.


transi is officially maintained and available from its ECMWF git page.

The master branch tracks the latest stable release, whereas the develop branch tracks the latest developments.

To download the project at the latest release we can type on the terminal the commands reported below:

git clone -b master


The transi build system is based on CMake which tries to automatically detect compilers and project dependencies. To avoid suprises make sure that the following environment variables are pointing to the correct compiler.

  • CC – Path to C compiler
  • CXX – Path to C++ compiler
  • Fortran – Path to Fortran compiler

Other environment variables which may help CMake (version greater than 3.12) in finding useful dependencies for Atlas:

  • ecbuild_ROOT – Path to ecbuild install prefix
  • MPI_ROOT – Path to MPI install prefix
  • MKLROOT – Path to Intel MKL install prefix
  • FFTW_ROOT – Path to FFTW install prefix

transi can be configured and installed as follows, to a given path-to-install as shown below:

cd transi
mkdir build && cd build
cmake ../ -DCMAKE_MODULE_PATH=$ecbuild_ROOT/share/cmake/ecbuild \
make install

If Atlas is the only reason to install transi, it is OK to have several (undocumented) features disabled. It is then safe to add following to the arguments to the cmake configuration above: