SUBROUTINE qromb(func,a,b,ss)
      INTEGER JMAX,JMAXP,K,KM
      REAL a,b,func,ss,EPS
      EXTERNAL func
      PARAMETER (EPS=1.e-6, JMAX=20, JMAXP=JMAX+1, K=5, KM=K-1)
CU    USES polint,trapzd
      INTEGER j
      REAL dss,h(JMAXP),s(JMAXP)
      h(1)=1.
      do 11 j=1,JMAX
        call trapzd(func,a,b,s(j),j)
        if (j.ge.K) then
          call polint(h(j-KM),s(j-KM),K,0.,ss,dss)
          if (abs(dss).le.EPS*abs(ss)) return
        endif
        s(j+1)=s(j)
        h(j+1)=0.25*h(j)
11    continue
      pause 'too many steps in qromb'
      END
C  (C) Copr. 1986-92 Numerical Recipes Software .