!### 2015/05/03 Yuta Ando (Mie University)

subroutine highpassfilter_rmean(A,tmax,filt,undef)
  implicit none
  integer :: t,tmax,filt,tt,n,it
  real :: A(tmax),undef,sum,B(tmax)

  sum=0.
  do t=1,tmax
    sum=0.
    n=0
    do tt=-(filt-1)/2,(filt-1)/2
      it=t+tt
      if(it<1)it=1
      if(it>tmax)it=tmax
      if(A(it)/=undef)then
        n=n+1
        sum=sum+A(it)
      endif
    enddo
    if(n==0)then
      B(t)=undef
    else
      sum=sum/real(n)
      B(t)=A(t)-sum
      if(A(t)==undef)B(t)=undef
    endif
  enddo
  A(:)=B(:)

end subroutine