Feb 11, 2026 minutes

Author: DrTimothyAldenDavis

minutes/2025-12-17.md

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+Minutes, Dec 17, 2025
+
+    * agenda:
+
+        - assign one or more algorithms or utilities to everyone for review
+            (see below): LAGraph
+
+--------------------------------------------------------------------------------
+
+    consider these methods for src.  Minor revisions needed in some of them,
+    including API revisions:
+
+        LAGr_BreadthFirstSearch_Extended.c: uses LG_:
+            LG_BreadthFirstSearch_SSGrB_Extended.c
+            LG_BreadthFirstSearch_vanilla_Extended.c    (skip this?)
+        LAGr_PeerPressureClustering.c
+        LAGraph_AllKCore.c: need both basic & adv methods; this is mixed
+        LAGraph_AllKTruss.c
+        LAGraph_HITS.c
+        LAGraph_Hdip_Fiedler.c: needs lots of polish
+        LAGraph_KCore.c: need both basic & adv
+        LAGraph_KTruss.c
+        LAGraph_MaximalIndependentSet.c: rename LAGr_, need a basic method
+        LAGraph_SquareClustering.c
+        LAGraph_VertexCentrality_Triangle.c
+        LAGraph_coloring_MIS.c
+        LAGraph_coloring_independent_set.c
+        LAGraph_lcc.c
+
+    abandon the need for vanilla methods and just return GrB_NOT_IMPLEMENTED
+    if not using SuiteSparse/GraphBLAS.h.
+
+        LAGr_EdgeBetweennessCentrality.c
+        LAGr_MarkovClustering.c (but see latest issue posted)
+        LAGr_Modularity.c
+        LAGr_PartitionQuality.c
+        LAGr_SwapEdges.c
+        LAGraph_SwapEdges.c
+        LAGraph_CFL_reachability.c
+        LAGraph_EstimateDiameter.c
+        LAGraph_ExactDiameter.c
+        LAGraph_FastGraphletTransform.c
+        LAGraph_KCoreDecompose.c
+        LAGraph_MultiSourceBFS.c
+        LAGraph_RegularPathQuery.c
+        LAGraph_RichClubCoefficient.c
+        LAGraph_scc.c
+        LG_CC_FastSV5.c
+        LG_CC_FastSV7_FA.c
+
+    Algorithms need work:
+
+        LAGr_MaxFlow.c (need to provide output R matrix?  And flow_matrix is
+                expensive to compute; revise)
+        LAGraph_argminmax.c
+        LAGraph_msf.c
+        LAGraph_BF_*.c: need just one variant
+        LAGraph_cdlp.c: use Container methods
+
+    need new LAGraph_Graph enums for these algorithms:
+
+        LAGraph_MaximalMatching.c: need LAGraph_Graph incidence matrix
+        LAGraph_Coarsen_Matching.c: need LAGraph_Graph incidence matrix
+        LAGr_MaximumMatching.c:  need to switch to Container methods;
+            need LAGraph_Graph bipartite graph
+        LAGraph_cc_lacc.c: unsure
+
+    do not consider these algorithms:
+
+        LAGr_PageRankGX.c: for LDBC benchmarks only
+        LAGr_TriangleCount_GPU.c: for testing draft GPU kernels only
+        LAGraph_dnn.c: for an IEEE HPEC Graph Challenge only
+        LAGraph_HelloWorld.c: will always be experimental
+        LAGraph_cdlp_withsort.c: OK, but slow, see LAGraph_cdlp instead
+
+    add these Utilities to src:
+
+        LAGraph_FastAssign.c
+        LAGraph_Incidence_Matrix.c      but we need an LAGraph_Graph incidence matrix?
+        LAGraph_Matrix_Hash.c
+        LAGraph_Random_Matrix.c
+
+    do not add these Utilities to src; will be superseded by binsparse:
+
+        LAGraph_SFreeContents.c
+        LAGraph_SFreeSet.c
+        LAGraph_SLoadSet.c
+        LAGraph_SRead.c
+        LAGraph_SSaveSet.c
+        LAGraph_SWrite.c
+

minutes/2026-02-11.md

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+# LAGraph Working Group Meeting Minutes - Feb 11, 2026
+
+## Attendees
+- [x] Tim Davis
+- [x] Gabe Gomez
+- [x] Tim Mattson
+- [x] Scott McMillan
+- [x] Michel Pelletier
+
+## Agenda and Minutes
+
+**Agenda** by Tim Davis
+
+**Minutes** by Tim Davis
+
+We discussed the LAGraph API, using this spreadsheet:
+https://docs.google.com/spreadsheets/d/1-WnAsmrHRYh5KQeJZzMtZYZKiKblGKYOOIkw0MdokuU/edit?usp=sharing
+
+We decided that all methods in src/algorithm must come in pairs:
+`LAGraph_[method]` and `LAGr_[method]`, for both Basic and Advanced.  Utilities
+in src/utility will be Basic only, as `LAGraph_[method]`.
+
+Basic methods can modify their input graph(s), while Advanced ones do not.  In
+particular, Basic methods can add cached properties to their graph(s), while
+Advanced methods will return an error if they require a cached property that is
+missing.  If a Basic method does not modify its input graph and the Advanced
+method needs no cached properties, then they are identical, but we will add the
+pair of `LAGraph_[method]` and `LAGr_[method]` methods anyway, for consistency.
+
+The `LAGr_Init`, `LAGraph_Init`, `LAGraph_Finalize`, `LAGr_SampleDegree`, and
+`LAGr_SortByDegree` methods will be moved to src/algorithm.  We need to add
+`LAGr_Finalize`, `LAGraph_SortByDegree`, and `LAGraph_SampleDegree`.
+
+We discussed the possibility that the `LAGr_Init` and `LAGr_Finalize`
+pair of methods will (optionally) not call `GrB_init` and `GrB_finalize`,
+respectively.
+
+We need to rename `LAGr_Betweenness` to `LAGr_BetweennessCentrality`,
+since there are other centrality metrics in experimental/algorithm.
+This is a breaking change in the API, so LAGraph would become v2.0.
+Applications that rely on LAGraph 1.x would need to be revised with the
+new name.
+
+To discuss:  replacing C pointers to array with `GrB_Vectors`, and replacing C
+input/output scalars with `GrB_Scalars`.  This will cause additional breaking
+changes in the src/ methods, if we make this change.  For example,
+`LAGr_Betweenness` takes as input `uint64_t *sources` and `int32_t ns`.  This
+could be replaced by a single `GrB_Vector sources`, as is already done in
+`LAGr_EdgeBetweennessCentrality`.  (So should `LAGr_Betweenness` be renamed to
+`LAGr_VertexBetweennessCentrality`?)
+
+Adding this `GrB_Vector` would also require a descriptor or flag to state which
+list of indices should be used for a vector v:  the indices I or values X from
+an implicit `GrB_extracTuples (I, X, v)` on the vector.
+