SpM

Sparse Modeling tool for analytical continuation from the imaginary-time Green's function to real-requency spectral function.

The algorithm is presented in the article

• J. Otsuki, M. Ohzeki, H. Shinaoka, K. Yoshimi,
  "Sparse modeling approach to analytical continuation of imaginary-time quantum Monte Carlo data"
  Phys. Rev. E 95, 061302(R) (2017).

Licence

This package is distributed under GNU General Public License version 3 (GPL v3).

We kindly ask you to cite the below articles in publications that include results obtained using this package.

• The article about original algorithm
  • J. Otsuki, M. Ohzeki, H. Shinaoka, K. Yoshimi,
    "Sparse modeling approach to analytical continuation of imaginary-time quantum Monte Carlo data"
    Phys. Rev. E 95, 061302(R) (2017).
• The article about this package
  • K. Yoshimi, J. Otsuki, Y. Motoyama, M. Ohzeki, and H. Shinaoka, "SpM: Sparse modeling tool for analytic continuation of imaginary-time Green's function" Comput. Phys. Commun. 244, 319-323 (2019).
• The article about the SpM-Pade method (please cite if you use)
  • Y. Motoyama, K. Yoshimi, and J. Otsuki, "Robust analytic continuation combining the advantages of the sparse modeling approach and Pade approximation" arXiv:2109.08370

Authors

Junya Otsuki, Kazuyoshi Yoshimi, Yuichi Motoyama, Hiroshi Shinaoka, Masayuki Ohzeki

Requirement

• LAPACK, BLAS
• FFTW3
• cpplapack (included in this package)

How to build

Getting the source codes

Download the latest source codes by

$ git clone https://github.com/j-otsuki/SpM.git spm.src

Then, the source codes are downloaded in the directory spm.src.

Using Cmake

Build with cmake command is done in a separate directory, e.g. spm.build. Type the following commands:

$ mkdir spm.build && cd spm.build
$ cmake ../spm.src
$ make

Then, the executable file SpM.out is created in directory spm.build/src.

Sample scripts

Some sample data are provided in samples directory:

• samples/fermion # sample for fermionic spectrum (data in the article)
• samples/boson # sample for bosonic spectrum

A script file, run.sh, is provided to run through the program. Enter into the directory samples/fermion, and execute the script by

$ ./run.sh

You may need to change the path to SpM.out in the script. If succeeded, results including graphs in eps format are created in output directory. For details, see the document linked below.

Official page

The official page of the SpM is here.