Butterfly Factorization (BF)

• 1D Butterfly Factorization

  Butterfly factorization for all 1D problems.

• 2D Butterfly Factorization

  • General Butterfly Factorization (GBF)

    Butterfly factorization for 2D problems without singularity at origin.

  • Polar Butterfly Factorization (PBF)

    Butterfly factorization for 2D problems with singularity at origin.

  • Multiscale Butterfly Factorization (MBF)

    Butterfly factorization for 2D problems with singularity at origin.