我如何从stdin读取数据到gnuplot并绘制两次相同的数据 [英] How do I read data from stdin to gnuplot and plot same data twice

问题描述

我有一个程序，该程序生成带有几个输入参数的数据并将其吐出到stdout，我将此数据通过管道传输到gnuplot并进行绘制(在我的情况下，我没有中间文件):

I have a program that generates data with a couple of input arguments and spits it out to stdout, I pipe this data to gnuplot and plot it (in my case I don't have an intermediate file):

$ cat sample_data.dat | gnuplot plot_script.gp

sample_data.dat:

sample_data.dat:

0  0.5000    
1  0.9225    
2  0.2638    
3  0.7166    
4  0.7492    

plot_script.gp

plot_script.gp

#!/usr/bin/gnuplot
set terminal wxt size 700,524 enhanced font 'Verdana,10' persist

set style line 1 lc rgb '#0060ad' pt 7 lt 1 lw 0.5 # circle blue thin line
set style line 2 lc rgb '#949599' lt 1 lw 1 # --- grey

plot "<cat" using 1:2 w lp ls 1 notitle

我想完成的事情就是这样

what I want to accomplish is something like this

 plot "<cat" using 1:2 w l ls 2 notitle, \
      "" using 1:2 w p ls 1 notitle

也就是说，我希望线条使用一种颜色，而点使用另一种颜色.我只是可以找到解决方案.

That is, I want the line in one colour and the dots in another. I just can figure out a solution for this.

我可以将stdin读取为变量来存储它，以便将其绘制两次吗?

Could I read the stdin to a variable to store it so I could plot it twice?

关于stackoverflow的问题有些紧迫，但我没有什么真正可以用来解决我的问题的， gnuplot-plot-two-data-set-from-stdin 和 pipe-plot-data-to-gnuplot-script

There are some close questions on stackoverflow but nothing that I could really use to figure out to fit my problem, gnuplot-plot-two-data-set-from-stdin and pipe-plot-data-to-gnuplot-script

我现在也尝试过这种方法:

I have now tried this as well:

plot for[col=2:3] "<awk '{print $1,$2,$2}'" using 1:col w lp ls col notitle

推荐答案

在将数据发送到gnuplot之前，必须对其进行复制.在类似Unix的系统上实现此目的的一种方法是

You must duplicate your data before you send it to gnuplot. A way to to this on Unix-like systems is

$ cat sample_data.dat | cat - <(echo 'e') | tee - | gnuplot script.gp

并使用您已有的脚本，例如

and using the script which you already have, like

plot '<cat' w l, '' w p

在gnuplot 5中，您还可以在gnuplot内部使用一些技巧，例如

In gnuplot 5 one could also use some trickery inside of gnuplot like

data = system('cat -')
set print $db
print data
unset print
plot $db w l, $db w p

并仅用

gnuplot plot_script.gp < sample_data.dat

这篇关于我如何从stdin读取数据到gnuplot并绘制两次相同的数据的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！