SymArrays.jl

SymArr_ifsym(A,Nsyms) make a SymArray if there is some symmetry (i.e., any of the Nsyms are not 1)

based on Base.binomial, but without negative values for n and without overflow checks (index calculations here should not overflow if the array does not have more elements than an Int64 can represent)

Check if the arguments correspond to a valid contraction. Do all "static" checks at compile time.

A[iAprev,icntrct,iApost] S[iSprev,Icntrct,ISpost] res[iAprev,iApost,iSprev,Icntrct-1,ISpost]

convert a linear index for a symmetric index group into a group of subindices

storage_type(A)

Return the type of the underlying storage array for array wrappers.

size of a single symmetric group with Nsym dimensions and size Nt per dimension

calculates the linear index corresponding to the symmetric index group (i1,...,iNsym)

calculates the contribution of index idim in (i1,...,idim,...,iN) to the corresponding linear index for the group

return the symmetry group index and the number of symmetric indices in the group