|int||dpivotL (const int jcol, const double u, int *usepr, int *perm_r, int *iperm_r, int *iperm_c, int *pivrow, GlobalLU_t *Glu, SuperLUStat_t *stat)|
-- SuperLU routine (version 3.0) -- Univ. of California Berkeley, Xerox Palo Alto Research Center, and Lawrence Berkeley National Lab. October 15, 2003
Copyright (c) 1994 by Xerox Corporation. All rights reserved.
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Permission is hereby granted to use or copy this program for any purpose, provided the above notices are retained on all copies. Permission to modify the code and to distribute modified code is granted, provided the above notices are retained, and a notice that the code was modified is included with the above copyright notice.
|int dpivotL||(||const int||jcol,|
Purpose ======= Performs the numerical pivoting on the current column of L, and the CDIV operation.
Pivot policy: (1) Compute thresh = u * max_(i>=j) abs(A_ij); (2) IF user specifies pivot row k and abs(A_kj) >= thresh THEN pivot row = k; ELSE IF abs(A_jj) >= thresh THEN pivot row = j; ELSE pivot row = m;
Note: If you absolutely want to use a given pivot order, then set u=0.0.
Return value: 0 success; i > 0 U(i,i) is exactly zero.