gnuplot 複数行で移動平均 filter

nearint(x)=(x - floor(x) <= 0.5 ? floor(x) : floor(x)+1)

filter(x,y)=nearint(x/y)*y

plot "memo.csv" using (filter($1,20)):4 smooth unique , "memo.csv" using (filter($1,20)):3 smooth unique, "memo.csv" using (filter($1,20)):2 smooth unique;


http://www.ss.scphys.kyoto-u.ac.jp/person/yonezawa/contents/program/gnuplot/average.html