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function [x no_value] = GB_spec_Matrix_extractElement (A, i, j, xclass)
%GB_SPEC_MATRIX_EXTRACTELEMENT a MATLAB mimic of GrB_Matrix_extractElement
% SuiteSparse:GraphBLAS, Timothy A. Davis, (c) 2017-2020, All Rights Reserved.
% http://suitesparse.com See GraphBLAS/Doc/License.txt for license.
A = GB_spec_matrix (A) ;
if (nargin < 4)
xclass = A.class ;
end
% GraphBLAS indices are zero based, but (i,j) below must be 1-based
i = i+1 ;
j = j+1 ;
no_value = ~(A.pattern (i,j)) ;
if (no_value)
% The spec says x is not modified, but a MATLAB function must assign a
% value to all its outputs. The mexFunction interface to GraphBLAS
% also returns zero in this case.
x = 0 ;
else
x = A.matrix (i,j) ;
end
x = GB_mex_cast (x, xclass) ;
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