1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82
|
function C = GB_spec_subassign (C, Mask, accum, A, I, J, descriptor, scalar)
%GB_SPEC_SUBASSIGN a mimic of GxB_subassign
%
% Usage:
% C = GB_spec_subassign (C, Mask, accum, A, I, J, descriptor, scalar)
%
% Computes C(I,J)<Mask> = accum(C(I,J),A), in GraphBLAS notation.
%
% This function does the same thing as GxB_Matrix_subassign,
% GxB_Vector_subassign, GxB_Matrix_subassign_TYPE, GxB_Vector_subassign_TYPE,
% GxB_Row_subassign, and GxB_Col_subassign functions. In all cases, the Mask
% is the same size as A (after optionally being transpose) and the submatrix
% C(I,J). Entries outside the C(I,J) submatrix are never modified.
% SuiteSparse:GraphBLAS, Timothy A. Davis, (c) 2017-2022, All Rights Reserved.
% SPDX-License-Identifier: Apache-2.0
%-------------------------------------------------------------------------------
% get inputs
%-------------------------------------------------------------------------------
if (nargout > 1 || nargin ~= 8)
error ('usage: C = GB_spec_subassign (C, Mask, accum, A, I, J, descriptor, scalar)') ;
end
% Convert inputs to dense matrices with explicit patterns and types,
% and with where X(~X.pattern)==identity for all matrices A, B, and C.
C = GB_spec_matrix (C) ;
A = GB_spec_matrix (A) ;
[C_replace Mask_comp Atrans Btrans Mask_struct] = ...
GB_spec_descriptor (descriptor) ;
Mask = GB_spec_getmask (Mask, Mask_struct) ;
%-------------------------------------------------------------------------------
% apply the descriptor to A
if (Atrans)
A.matrix = A.matrix.' ;
A.pattern = A.pattern' ;
end
% expand I and J if empty
if (ischar (I) & isempty (I))
% I = '' is treated as the empty list
I = [ ] ;
elseif (isempty (I) || isequal (I, ':'))
% I = [ ] is treated as ":"
nrows = size (C.matrix, 1) ;
I = 1:nrows ;
end
if (ischar (J) & isempty (J))
% J = '' is treated as the empty list
J = [ ] ;
elseif (isempty (J) || isequal (J, ':'))
% J = [ ] is treated as the ":"
ncols = size (C.matrix, 2) ;
J = 1:ncols ;
end
if (scalar)
% scalar expansion: expand A into a matrix
ni = length (I) ;
nj = length (J) ;
A.matrix (1:ni, 1:nj) = A.matrix (1,1) ;
A.pattern (1:ni, 1:nj) = A.pattern (1,1) ;
end
S.matrix = C.matrix (I,J) ;
S.pattern = C.pattern (I,J) ;
S.class = C.class ;
% T = A
T.matrix = A.matrix ;
T.pattern = A.pattern ;
% S<Mask> = accum (S,T): apply the accum, then Mask, and return the result
S = GB_spec_accum_mask (S, Mask, accum, T, C_replace, Mask_comp, 0) ;
C.matrix (I,J) = S.matrix ;
C.pattern (I,J) = S.pattern ;
C.class = S.class ;
|