用gnuplot画数据图

set terminal jpeg 
set title "xxx"
set xyplane at 0
set xlabel "time" 
set style data lines
set style line 1 lt rgb "red" lw 1
set style line 2 lt rgb "blue" lw 1
set output "a.jpg"
plot 'a1.txt' using 1:2 ls 1 title "T3" ,'a1.txt' using  1:3 ls 2 title "T4"
pause -1 "xxxx"

然后a1.txt是提取的数据

cut -d ‘ ’ -f 1,7,8 a.txt > a1.txt

提取1，7，8三列的数据，空格做分割。