Document usage of UMFPACK control vector #448

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sjdaines opened this issue Oct 1, 2023 · 0 comments · Fixed by #449

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sjdaines commented Oct 1, 2023 •

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The documentation for UMFPACK lu could use:

an explicit note/warning that Julia disables iterative refinement, which means that the Julia default is not the same as the defaults given in the UMFPACK manual. This is an intentional change, Performance issue with (sparse) backsolve after LU factorization (turn off iterative refinement by default) #122, but isn't documented
an example of how to set the control vector and display it

eg

umfpack_control = SparseArrays.UMFPACK.get_umfpack_control(Float64, Int64) # read defaults for a Float64 sparse matrix
SparseArrays.UMFPACK.show_umf_ctrl(umfpack_control) # display values
umfpack_control[SparseArrays.UMFPACK.JL_UMFPACK_IRSTEP] = 2.0 # reenable iterative refinement (2 is UMFPACK default max iterative refinement steps, Julia modifies this default to disable iterative refinement)

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sjdaines mentioned this issue

Add example for UMFPACK control vector #449

Merged

ViralBShah closed this as completed in #449

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