Mercurial > octave-nkf

view libcruft/odepack/vnorm.f @ 14688:42edbe6f6a8d stable

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Fix bad two-arg call of randperm (bug #36535) * rand.cc (Frandperm): Rewrite algorithm for short_shuffle. Add another test.
author Jordi Gutiérrez Hermoso <jordigh@octave.org>
date Fri, 25 May 2012 11:24:02 -0400
parents 30c606bec7a8
children
line wrap: on
line source

      DOUBLE PRECISION FUNCTION VNORM (N, V, W)
CLLL. OPTIMIZE
C-----------------------------------------------------------------------
C THIS FUNCTION ROUTINE COMPUTES THE WEIGHTED ROOT-MEAN-SQUARE NORM
C OF THE VECTOR OF LENGTH N CONTAINED IN THE ARRAY V, WITH WEIGHTS
C CONTAINED IN THE ARRAY W OF LENGTH N..
C   VNORM = SQRT( (1/N) * SUM( V(I)*W(I) )**2 )
C-----------------------------------------------------------------------
      INTEGER N,   I
      DOUBLE PRECISION V, W,   SUM
      DIMENSION V(N), W(N)
      SUM = 0.0D0
      DO 10 I = 1,N 
 10     SUM = SUM + (V(I)*W(I))**2
      VNORM = DSQRT(SUM/DBLE(N))      
      RETURN
C----------------------- END OF FUNCTION VNORM -------------------------
      END