// Program to plot Delta-T values g = new graphics p = new polyline for y=1000 to 2500 { d = eval["#" + padLeft["$y", 4, "0"] + "#"] println["$d\t" + (deltaT[d]->s)] p.addPoint[JD[d], -deltaT[d]/s] } g.add[p] p2 = new polyline // Now read data from US Naval Observatory and overlay it. for line = lines["http://maia.usno.navy.mil/ser7/deltat.data"] { if [year, month, day, deltaT] = line =~ %r/\s*(\d{4})\s+(\d{1,2})\s+(\d{1,2})\s+(\d+\.\d+)/ { month = padLeft[month, 2, "0"] day = padLeft[day, 2, "0"] date = parseDate["$year-$month-$day UTC"] println["$date\t$dt"] dt = eval[deltaT] s p2.addPoint[JD[date], -dt/s] } } g.color[0,0,1] g.add[p2] g.show[]