http://stackoverflow.com/questions/6564561/gnuplot-conditional-plotting-plot-col-acol-b-if-col-c-x
How can I do this in gnuplot:
plot "test.csv" using 1:2 if value_in_column_3 == 80.0
It should only select those rows where column 3 == 80.0 and ignore all other rows (It should not plot a 0 for the other rows, simply ignore them)
Thanks in advance.
gnuplot conditional plotting: plot col A:col B if col C == x
原文：http://www.cnblogs.com/zkwarrior/p/5858339.html