subroutine penrgy(p,wp,wpp)
c
c Volume integral of p(x,y)**2
c
      implicit none
      include 'itg.par'
      real p(lz,mz,nz,nspecz),wpp(mz,nz),wp,coef
      integer l,m,n
      include 'itg.cmn'
c
c ... note dr(l)=2.0*dx
c ... normalize by delta=pi*y0 in the x-direction
c
      wp=0.0
      coef=0.25/(pi*y0)
c
      do 10 n=1,nd
      do 10 m=1,md
      wpp(m,n)=p(1,m,n,1)*p(1,m,n,1)*dr(1)*0.5
      do 20 l=2,ldb
      wpp(m,n)=wpp(m,n)+p(l,m,n,1)*p(l,m,n,1)*dr(l)
   20 continue
      wpp(m,n)=wpp(m,n)+p(ld,m,n,1)*p(ld,m,n,1)*dr(ld)*0.5
      wpp(m,n)=coef*wpp(m,n)
      wp=wp+wpp(m,n)
   10 continue
c
      return
      end