d4/db5/ddanrm_8f_source.html

       DOUBLE PRECISION FUNCTION ddanrm (NEQ, V, WT, RPAR, IPAR)

 C***BEGIN PROLOGUE  DDANRM

 C***SUBSIDIARY

 C***PURPOSE  Compute vector norm for DDASSL.

 C***LIBRARY   SLATEC (DASSL)

 C***TYPE      DOUBLE PRECISION (SDANRM-S, DDANRM-D)

 C***AUTHOR  PETZOLD, LINDA R., (LLNL)

 C***DESCRIPTION

 C-----------------------------------------------------------------------

 C     THIS FUNCTION ROUTINE COMPUTES THE WEIGHTED

 C     ROOT-MEAN-SQUARE NORM OF THE VECTOR OF LENGTH

 C     NEQ CONTAINED IN THE ARRAY V,WITH WEIGHTS

 C     CONTAINED IN THE ARRAY WT OF LENGTH NEQ.

 C        DDANRM=SQRT((1/NEQ)*SUM(V(I)/WT(I))**2)

 C-----------------------------------------------------------------------

 C***ROUTINES CALLED  (NONE)

 C***REVISION HISTORY  (YYMMDD)

 C   830315  DATE WRITTEN

 C   901009  Finished conversion to SLATEC 4.0 format (F.N.Fritsch)

 C   901019  Merged changes made by C. Ulrich with SLATEC 4.0 format.

 C   901026  Added explicit declarations for all variables and minor

 C           cosmetic changes to prologue.  (FNF)

 C***END PROLOGUE  DDANRM

 C

       INTEGER  NEQ, IPAR(*)

       DOUBLE PRECISION  V(neq), WT(neq), RPAR(*)

 C

       INTEGER  I

       DOUBLE PRECISION  SUM, VMAX

 C

 C***FIRST EXECUTABLE STATEMENT  DDANRM

       ddanrm = 0.0d0

       vmax = 0.0d0

       DO 10 i = 1,neq

         IF(abs(v(i)/wt(i)) .GT. vmax) vmax = abs(v(i)/wt(i))

 10      CONTINUE

       IF(vmax .LE. 0.0d0) go to 30

       sum = 0.0d0

       DO 20 i = 1,neq

 20      sum = sum + ((v(i)/wt(i))/vmax)**2

       ddanrm = vmax*sqrt(sum/neq)

 30    CONTINUE

       RETURN

 C------END OF FUNCTION DDANRM------

       END

to
may be zero for pure relative error test tem the relative tolerance must be greater than or equal to
Definition: Quad-opts.cc:233

abs
OCTAVE_EXPORT octave_value_list return the value of the option it must match the dimension of the state and the relative tolerance must also be a vector of the same length tem it must match the dimension of the state and the absolute tolerance must also be a vector of the same length The local error test applied at each integration step is xample roup abs(local error in x(i))<

octave_value::sqrt
octave_value sqrt(void) const
Definition: ov.h:1388