integer*8 peph
integer res
real(8) jd0
real(8) dt1, dt2
real(8) PV(6)
TYPE(C_PTR) :: peph

jd0 = 2442457
dt1 = 0.5D0
dt2 = 0.9D0
peph = calceph_open("example1.dat"//C_NULL_CHAR)
if (C_ASSOCIATED(peph)) then

   ! the heliocentric coordinates of Mars
   res = calceph_compute(peph,jd0, dt1, 4, 11, PV)
   write(*,*) PV

   res = calceph_compute(peph,jd0, dt2, 4, 11, PV)
   write(*,*) PV

    call calceph_close(peph)
 endif