~~DISCUSSION:off~~
====== gnuplot 在终端绘图 ======


===== ASCII 终端绘图 =====

<code>
gnuplot
set term dumb
plot sin(x)
q
</code>

  * 数据文件 ''test.csv''

<code>
123 145
143 156
156 178
165 189
168 199
176 203
</code>

  * 绘图命令

<code bash>
gnuplot

gnuplot> set term dumb
Terminal type set to 'dumb'
Options are 'feed  size 79, 24'
gnuplot> plot 'test.csv' u ($0):1 w lp t 'c1', 'test.csv' u ($0):2 w lp t 'c2'

gnuplot> q
</code>

  * 直接执行命令绘图

<code bash>
gnuplot -e "set term dumb; plot 'test.csv';"
gnuplot -e 'set term dumb; plot "test.csv" u ($0):1 w lp t "c1", "test.csv" u ($0):2 w lp t "c2";'
</code>

===== gnuplot 常用命令 =====

<code bash>
gnuplot> h plot           # 查看帮助文档
gnuplot> set term dumb    # 切换输出模式
gnuplot> !cat text2.csv   # 执行 shell 命令

gnuplot> p x    (绘制 y = x 函数)
gnuplot> plot [-pi:pi] sin(x)    # 设置坐标
gnuplot> splot [-10:10] [-20:20] x**2+y   # 绘制简单的三位函数图, 比如绘制z(x,y)=x2+y
gnuplot> plot sin(1.5 * x)

gnuplot> plot 'test.csv' title 'c1'   # 设置图例名称
gnuplot> plot 'test.csv' using 1:2    # 选取数据列绘图

gnuplot> plot 'test.csv' with lines          # 选择线条风格
gnuplot> plot 'test.csv' with linespoints
gnuplot> plot 'test.csv' with points

gnuplot> plot 'test.csv' using ($0):1, 'test.csv' using ($0):2   # 使用行号作为横轴

# 设置标题
gnuplot> set title 'Test Title'
gnuplot> set xlabel 'Times'
gnuplot> set ylabel 'Cost/ms'

gnuplot> set arrow 1 from 1,200 to 0.2,208   # 设置注释箭头
gnuplot> show arrow

set key at 2, 0.5               # 设置注释图例
set label "y=x" at 0, 208       # 设置注释文本
</code>

===== gnuplot 编写脚本 =====

==== demo01 ====

  * 脚本文件 ''demo01.plt''

<code>
set encoding utf8

# set terminal pdfcairo enhanced size 4in,3in font "Times New Roman,12"
# set output "demo01.pdf"

set term dumb

set tics nomirror
set xtics norangelimit
set key box inside
set key at 2.5, 0.95
set xlabel 'time'
set ylabel 'velocity'

plot "data01.txt" using 1:2 with lines ls 1 lw 2 title "pos1", \
"" using 1:3 with linespoints ls 2 lw 1 pointtype 12 ps 1 title "pos2", \

replot
reset
print "Done！"

</code>

  * 数据文件 ''data01.txt''

<code>
1 0.2893 0.3061
2 0.3636 0.2857
3 0.2562 0.2041
4 0.1983 0.1633
5 0.4463 0.5714
6 0.6033 0.5714
7 0.9008 0.8571
8 0.2727 0.5714
9 0.7355 0.8367
10 0.1322 0.1837
</code>

  * 绘制命令

<code bash>
gnuplot demo01.plt
</code>

==== demo02 ====


  * 脚本文件 ''demo02.plt''

<code>
# set terminal pngcairo  transparent enhanced font "arial,10" fontscale 1.0 size 600, 400
# set output 'histograms.2.png'
set encoding default
# set terminal emf size 800,600 font "Times New Roman,12"
# set output "pic2.emf"
set term dumb

set boxwidth 0.9 absolute
set style fill solid 1.00 border lt -1
set key inside right top vertical Right noreverse noenhanced autotitle nobox
set style histogram clustered gap 1 title textcolor lt -1
# set minussign
# set datafile missing '-'
set style data histograms
set xtics border in scale 0,0 nomirror rotate by -45  autojustify
set xtics  norangelimit
set xtics  ()

set xlabel '时间'
set ylabel '速度'

plot 'data02.txt' using 2:xtic(1) ti col , '' u 3 ti col

reset
print "Done!"

</code>

  * 数据文件 ''data02.txt''

<code>
时间  pos1  pos2
1	0.4824	0.4845
2	0.5941	0.5876
3	0.8882	0.9175
4	0.3588	0.7423
5	0.7647	0.6186
6	0.1471	0.1546
</code>

  * 绘制命令

<code bash>
gnuplot demo02.plt
</code>