pointperiod=5
lastPointToShow = 750

# show almost the whole trajectory by a thin line,
# every 5th point along the line (but only since tmin2)
# and show the final point by an arrow (vector)
plot 'output/sun' w p ps 3 pt 5,  \
 'output/0' every 1::tmin1::tmax1           u 2:3  w l ls  2,\
 'output/0' every pointperiod::tmin2::tmax2 u 2:3  w p ps 4 pt 4,\
 'output/0' every 1::tmax1::tmax1           u 2:3:4:5 w vector ls 5
 pause 0.1
 
## update the range we are showing; increment the last point
tmax1=tmax1+2
## and make the others consistent
tmin1=tmax1-2000 ;                    if(tmin1<0) tmin1 = 0 
tmin2=tmax1-pointperiod*12 ;          if(tmin2<0) tmin2 = 0 
tmin2=(tmin2/pointperiod)*pointperiod
tmax2=tmax1

if ( tmax1 < lastPointToShow ) call 'gnu21'