Downloading and Installing q3dfit

q3dfit is only supported and tested for Python 3.7-3.9. We recommend installation via pip:

pip install q3dfit

Optional multi-processing capability

q3dfit has the optional capability to parallelize fitting across multiple processor cores using the Message Passing Interface (MPI) standard. This is accomplished using the mpich package and its python wrapper mpi4py. Installation instructions for mpich vary dependending on the user’s system configurations. Some common methods include:

  • Install via Macports:

    sudo port install mpich
    sudo port select --set mpi mpich-mp-fortran
  • Install via Brew:

    brew install mpich
  • Install via Conda:

    conda install mpich

If mpich is successfully installed, you should be able to locate the path to its main executable by typing which mpiexec.

The final step is to install mpi4py, the mpich wrapper for the multi-processor mode. This can be done by

conda install mpi4py


pip install mpi4py==3.1.3