la05as.f
SUBROUTINE LA05AS (A, IND, NZ, IA, N, IP, IW, W, G, U)
C***BEGIN PROLOGUE LA05AS
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Warning: this routine is not intended to be user-callable.
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C***SUBSIDIARY
C***PURPOSE Subsidiary to SPLP
C***LIBRARY SLATEC
C***TYPE SINGLE PRECISION (LA05AS-S, LA05AD-D)
C***AUTHOR (UNKNOWN)
C***DESCRIPTION
C
C THIS SUBPROGRAM IS A SLIGHT MODIFICATION OF A SUBPROGRAM
C FROM THE C. 1979 AERE HARWELL LIBRARY. THE NAME OF THE
C CORRESPONDING HARWELL CODE CAN BE OBTAINED BY DELETING
C THE FINAL LETTER =S= IN THE NAMES USED HERE.
C REVISIONS MADE BY R J HANSON, SNLA, AUGUST, 1979.
C REVISED SEP. 13, 1979.
C
C ROYALTIES HAVE BEEN PAID TO AERE-UK FOR USE OF THEIR CODES
C IN THE PACKAGE GIVEN HERE. ANY PRIMARY USAGE OF THE HARWELL
C SUBROUTINES REQUIRES A ROYALTY AGREEMENT AND PAYMENT BETWEEN
C THE USER AND AERE-UK. ANY USAGE OF THE SANDIA WRITTEN CODES
C SPLP( ) (WHICH USES THE HARWELL SUBROUTINES) IS PERMITTED.
C
C IP(I,1),IP(I,2) POINT TO THE START OF ROW/COL I.
C IW(I,1),IW(I,2) HOLD THE NUMBER OF NON-ZEROS IN ROW/COL I.
C DURING THE MAIN BODY OF THIS SUBROUTINE THE VECTORS IW(.,3),IW(.,5),
C IW(.,7) ARE USED TO HOLD DOUBLY LINKED LISTS OF ROWS THAT HAVE
C NOT BEEN PIVOTAL AND HAVE EQUAL NUMBERS OF NON-ZEROS.
C IW(.,4),IW(.,6),IW(.,8) HOLD SIMILAR LISTS FOR THE COLUMNS.
C IW(I,3),IW(I,4) HOLD FIRST ROW/COLUMN TO HAVE I NON-ZEROS
C OR ZERO IF THERE ARE NONE.
C IW(I,5), IW(I,6) HOLD ROW/COL NUMBER OF ROW/COL PRIOR TO ROW/COL I
C IN ITS LIST, OR ZERO IF NONE.
C IW(I,7), IW(I,8) HOLD ROW/COL NUMBER OF ROW/COL AFTER ROW/COL I
C IN ITS LIST, OR ZERO IF NONE.
C FOR ROWS/COLS THAT HAVE BEEN PIVOTAL IW(I,5),IW(I,6) HOLD NEGATION OF
C POSITION OF ROW/COL I IN THE PIVOTAL ORDERING.
C
C***SEE ALSO SPLP
C***ROUTINES CALLED LA05ES, MC20AS, R1MACH, XERMSG, XSETUN
C***COMMON BLOCKS LA05DS
C***REVISION HISTORY (YYMMDD)
C 811215 DATE WRITTEN
C 890531 Changed all specific intrinsics to generic. (WRB)
C 890605 Corrected references to XERRWV. (WRB)
C 890831 Modified array declarations. (WRB)
C 891214 Prologue converted to Version 4.0 format. (BAB)
C 900315 CALLs to XERROR changed to CALLs to XERMSG. (THJ)
C 900402 Added TYPE section. (WRB)
C 900510 Convert XERRWV calls to XERMSG calls. (RWC)
C***END PROLOGUE LA05AS