Sparse Linear Algebra
Sparse matrix solvers call functions from SuiteSparse. The following factorizations are available:
Type | Description |
---|---|
SuiteSparse.CHOLMOD.Factor |
Cholesky factorization |
SuiteSparse.UMFPACK.UmfpackLU |
LU factorization |
SuiteSparse.SPQR.QRSparse |
QR factorization |
Other solvers such as Pardiso.jl are as external packages. Arpack.jl provides eigs
and svds
for iterative solution of eigensystems and singular value decompositions.
These factorizations are described in the Linear Algebra
section of the manual:
SuiteSparse.CHOLMOD.lowrankupdate
Function
lowrankupdate(F::CHOLMOD.Factor, C::AbstractArray) -> FF::CHOLMOD.Factor
Get an LDLt
Factorization of A + C*C'
given an LDLt
or LLt
factorization F
of A
.
The returned factor is always an LDLt
factorization.
See also lowrankupdate!
, lowrankdowndate
, lowrankdowndate!
.
SuiteSparse.CHOLMOD.lowrankupdate!
Function
lowrankupdate!(F::CHOLMOD.Factor, C::AbstractArray)
Update an LDLt
or LLt
Factorization F
of A
to a factorization of A + C*C'
.
LLt
factorizations are converted to LDLt
.
See also lowrankupdate
, lowrankdowndate
, lowrankdowndate!
.
SuiteSparse.CHOLMOD.lowrankdowndate
Function
lowrankupdate(F::CHOLMOD.Factor, C::AbstractArray) -> FF::CHOLMOD.Factor
Get an LDLt
Factorization of A + C*C'
given an LDLt
or LLt
factorization F
of A
.
The returned factor is always an LDLt
factorization.
See also lowrankdowndate!
, lowrankupdate
, lowrankupdate!
.
SuiteSparse.CHOLMOD.lowrankdowndate!
Function
lowrankdowndate!(F::CHOLMOD.Factor, C::AbstractArray)
Update an LDLt
or LLt
Factorization F
of A
to a factorization of A - C*C'
.
LLt
factorizations are converted to LDLt
.
See also lowrankdowndate
, lowrankupdate
, lowrankupdate!
.
SuiteSparse.CHOLMOD.lowrankupdowndate!
Function
lowrankupdowndate!(F::CHOLMOD.Factor, C::Sparse, update::Cint)
Update an LDLt
or LLt
Factorization F
of A
to a factorization of A ± C*C'
.
If sparsity preserving factorization is used, i.e. L*L' == P*A*P'
then the new factor will be L*L' == P*A*P' + C'*C
update
: Cint(1)
for A + CC'
, Cint(0)
for A - CC'
© 2009–2021 Jeff Bezanson, Stefan Karpinski, Viral B. Shah, and other contributors
Licensed under the MIT License.
https://docs.julialang.org/en/v1.6.0/stdlib/SuiteSparse/