Python-graphblas

* GrB MATLAB interface: changed license from Apache-2.0 to GNU GPLv3 or later.

* demos: no longer built by default
* (24) bug fix: GB_PUBLIC added to the new functions in GraphBLAS.h
* GrB_Matrix_reduce_BinaryOp: reinstated from v4.0.3;
same limit on built-in ops that correspond to known monoids.
* Source/GB_control.h: more semirings disabled by default to reduce
compile time and binary library size. The semirings still work, but
are not as fast since they now use the generic methods.

* GrB_Matrix_reduce_BinaryOp: removed. Use a monoid instead, with
GrB_reduce or GrB_Matrix_reduce_Monoid.
* (23) bug fix: GrB_Matrix_apply_BinaryOp1st and 2nd were using the
wrong descriptors for GrB_INP0 and GrB_INP1.
* memory pool added for faster memory allocation
* calloc no longer used: using malloc+memset(0) instead
* realloc option: if not available, uses malloc+memcpy+free
* GrB MATLAB interface ported to MATLAB R2021a.
* GxB_Matrix_diag: construct a diagonal matrix from a vector
* GxB_Vector_diag: extract a diagonal from a matrix
* concat/split: added methods to concatenate and split matrices
* import/export: size of arrays now in bytes, not entries.
A new parameter, is_uniform, has been added to all import/export
methods, which indicates that the matrix values are all the same.
* (22) bug fix: SIMD vectorization was missing reduction(+,task_cnvals)
in GB_dense_subassign_06d_template.c. Caught by Jeff Huang, Texas A&M,
with his software package for race-condition detection. Good catch!



v4.0.4_GrAPL
Draft version of v4.0.4, used for results in GraAPL'21 submission.

(update: I seemed to have inadvertently left this version in Debug mode. To fix this, edit the CMakeLists.txt file, and comment out or delete line 88, "set ( CMAKE_BUILD_TYPE Debug )".

* faster min/max monoids
* MATLAB: G=GrB(G) converts G from v3 object to v4

Modified the MATLAB interface so that it can load *.mat files saved by GraphBLAS v3.

* substantial performance gains: compared with v3.3.3: up to 5x faster in
BFS (with LAGraph_bfs_parent2), 2x faster in Betweeness-Centrality (in
LAgraph_bc_bactch5); BC now faster than GAP for kron, urand, and
twitter (the 3 largest matrices in the GAP benchmark).
* GrB_wait(), with no inputs: removed
* GrB_wait(&object): polymorphic function added
* GrB_*_nvals: no longer guarantees completion; use GrB_wait for that
* GrB_error: now has two parameters: a string (char **) and an object
* GrB_Matrix_reduce_BinaryOp: limited to certain built-in ops
* GrB_*_extractTuples: may return indices out of order
* removed internal features: GBI iterator, slice and hyperslice matrices
* bitmap/full matrices and vectors added: faster and lower memory usage
when many entries present in a matrix or vector
* GxB_SPARSITY_CONTROL, GxB_SPARSITY_STATUS added: for matrix get/set
* positional operators and semirings: GxB_FIRSTI_INT32 and related ops
* jumbled matrices: sort left pending, like zombies and pending tuples
* GxB_get/set: added GxB_SPARSITY_* (hyper, sparse, bitmap, or full)
* GxB_HYPER: enum renamed to GxB_HYPER_SWITCH
* GxB_BITMAP_SWITCH added: for matrix/vector get/set and global get/set
* GxB*import/export: API modified
* GxB_SelectOp: nrows and ncols removed from function signature
* OpenMP tasking removed from mergesort: just as fast; now ports to Windows
* GxB_BURBLE added: for diagnostic output
* (21) bug fix: A({lo,hi})=scalar in MATLAB; A(lo:hi)=scalar was OK