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function C = GB_spec_Col_assign (C, Mask, accum, A, I, j, descriptor)
%GB_SPEC_COL_ASSIGN a MATLAB mimic of GrB_Col_assign
%
% Usage:
% C = GB_spec_Col_assign (C, Mask, accum, A, I, j, descriptor)
%
% Computes C<Mask>(I,j) = accum(C(I,j),A), in GraphBLAS notation.
%
% This function does the same thing as GrB_Col_assign
% SuiteSparse:GraphBLAS, Timothy A. Davis, (c) 2017-2020, All Rights Reserved.
% http://suitesparse.com See GraphBLAS/Doc/License.txt for license.
%-------------------------------------------------------------------------------
% get inputs
%-------------------------------------------------------------------------------
if (nargout > 1 || nargin ~= 7)
error ('usage: C = GB_spec_Col_assign (C, Mask, accum, A, I, j, descriptor)') ;
end
if (length (j) ~= 1)
error ('j must be a scalar') ;
end
% Convert inputs to dense matrices with explicit patterns and types,
C = GB_spec_matrix (C) ;
% extract the C(:,j) column
X.matrix = C.matrix (:,j) ;
X.pattern = C.pattern (:,j) ;
X.class = C.class ;
% X<Mask>(I) = accum (X(I),A)
X = GB_spec_assign (X, Mask, accum, A, I, 1, descriptor, 0) ;
% put the C(:,j) colum back
C.matrix (:,j) = X.matrix ;
C.pattern (:,j) = X.pattern ;
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