anchor.diff:  		spriorran(i:,1)= -kmax
   		spriorran(i:,2)= kmax
   
  +    else if (using_gp) then
  +    ! parameter array organization in this case:
  +    ! P1, K1, ecc1, omega1, t01, [P2, K2, ecc2, omega2, t02], vsys_obs1, [vsys_obs2], hyperpar1, hyperpar2
  +        !! systematic velocity(ies), Uniform, -kmax - kmax
  +        i = sdim-nextra+1
  +        spriorran(i:,1)= -kmax
  +        spriorran(i:,2)= kmax
  +
  +        !! hyperparameters
  +        i = sdim-nextra+nobserv+1
  +        spriorran(i:,1)= -1.d0
  +        spriorran(i:,2)= 1.d0
  +
   	else
  +    ! parameter array organization in this case:
  +    ! P1, K1, ecc1, omega1, t01, [P2, K2, ecc2, omega2, t02], vsys_obs1, [vsys_obs2]
   		!! systematic velocity(ies), Uniform, -kmax - kmax
  -		i = sdim-nextra+1 ! index of jitter parameter
  +		i = sdim-nextra+1
   		spriorran(i:,1)= -kmax
   		spriorran(i:,2)= kmax
   
   	end if	
   
  - 	!stop "we have to stop here"
  +    call MPI_INIT(ierr)
  +    call MPI_COMM_RANK(MPI_COMM_WORLD, i, ierr)
  +    if (i==0) then
  +        write(fmt,'(a,i2,a)')  '(',sdim,'f13.4)'
  +        write(*, fmt) spriorran(:,1)
  +        write(*, fmt) spriorran(:,2)
  +    end if
  +    call MPI_BARRIER(MPI_COMM_WORLD, ierr)
  +
  + 	stop "we have to stop here"
      	call nest_Sample
   
      	! deallocate memory
  
positive.code:     end if
  
      ! extra parameters are systematic velocities for each observatory 
      ! plus, if present, the jitter
      nextra = nextra + nobserv
  
  
      if (using_gp) then
      	k3 = DiagonalKernel((/1.d0/))
      	kernel_to_pass => k3
      	!k5 = ExpSquaredKernel((/ 1.d0, 1.d0 /))
      	!kernel_to_pass => k5
      	gp1 = GP(k3%evaluate_kernel(times, times), kernel_to_pass)
      	gp1%mean_fun => mean_fun_keplerian
  		gp_n_planets = 1
  		gp_n_planet_pars = 6
  
negative.code: 	character(len=40) line
  	character(len=1) delim
  	character(len=5), dimension(10) :: args
      character(len=100) :: fmt
  	integer :: nargs, k, ind1, ind2
  	integer, dimension(:), allocatable :: n_each_observ
  
  