00001 DOUBLE PRECISION FUNCTION DDANRM (NEQ, V, WT, RPAR, IPAR) 00002 C***BEGIN PROLOGUE DDANRM 00003 C***SUBSIDIARY 00004 C***PURPOSE Compute vector norm for DDASSL. 00005 C***LIBRARY SLATEC (DASSL) 00006 C***TYPE DOUBLE PRECISION (SDANRM-S, DDANRM-D) 00007 C***AUTHOR PETZOLD, LINDA R., (LLNL) 00008 C***DESCRIPTION 00009 C----------------------------------------------------------------------- 00010 C THIS FUNCTION ROUTINE COMPUTES THE WEIGHTED 00011 C ROOT-MEAN-SQUARE NORM OF THE VECTOR OF LENGTH 00012 C NEQ CONTAINED IN THE ARRAY V,WITH WEIGHTS 00013 C CONTAINED IN THE ARRAY WT OF LENGTH NEQ. 00014 C DDANRM=SQRT((1/NEQ)*SUM(V(I)/WT(I))**2) 00015 C----------------------------------------------------------------------- 00016 C***ROUTINES CALLED (NONE) 00017 C***REVISION HISTORY (YYMMDD) 00018 C 830315 DATE WRITTEN 00019 C 901009 Finished conversion to SLATEC 4.0 format (F.N.Fritsch) 00020 C 901019 Merged changes made by C. Ulrich with SLATEC 4.0 format. 00021 C 901026 Added explicit declarations for all variables and minor 00022 C cosmetic changes to prologue. (FNF) 00023 C***END PROLOGUE DDANRM 00024 C 00025 INTEGER NEQ, IPAR(*) 00026 DOUBLE PRECISION V(NEQ), WT(NEQ), RPAR(*) 00027 C 00028 INTEGER I 00029 DOUBLE PRECISION SUM, VMAX 00030 C 00031 C***FIRST EXECUTABLE STATEMENT DDANRM 00032 DDANRM = 0.0D0 00033 VMAX = 0.0D0 00034 DO 10 I = 1,NEQ 00035 IF(ABS(V(I)/WT(I)) .GT. VMAX) VMAX = ABS(V(I)/WT(I)) 00036 10 CONTINUE 00037 IF(VMAX .LE. 0.0D0) GO TO 30 00038 SUM = 0.0D0 00039 DO 20 I = 1,NEQ 00040 20 SUM = SUM + ((V(I)/WT(I))/VMAX)**2 00041 DDANRM = VMAX*SQRT(SUM/NEQ) 00042 30 CONTINUE 00043 RETURN 00044 C------END OF FUNCTION DDANRM------ 00045 END
1.7.1
