integer res
real(8) jd0
real(8) dt1, dt2
real(8) PV(6)
jd0 = 2442457
dt1 = 0.5D0
dt2 = 0.9D0
res = calceph_sopen("example1.dat"//C_NULL_CHAR)
if (res.eq.1) then
! the heliocentric coordinates of Mars
res = calceph_scompute(jd0, dt1, 4, 11, PV)
write (*,*) PV
res = calceph_scompute(jd0, dt2, 4, 11, PV)
write (*,*) PV
call calceph_sclose
endif