Parse Einsum expressions

[mofeing]

Expressions

• ijik->jk: Partial Trace
  • ii->: Trace
• ikjl,mnkl->ijmn: Tensor Contraction
  • ik,kj->jk: Matrix Multiplication
• ijkl->ilkj: Tensor Index Permutation
  • ij->ji: Matrix transposition
• ij,ij->ij: Hadamard (element-wise) product

Reference links

• https://numpy.org/doc/stable/reference/generated/numpy.einsum.html
• https://under-peter.github.io/OMEinsum.jl/stable/parsing/
• https://nextjournal.com/under-Peter/julia-summer-of-einsum