Welcome seplot, a plotting tool to be used from the command line, or from a python script. It is a front-end for my favorite plotting program, PyX.
To install it, just use :
$ pip3 install seplot
Then you can use it to plot data stored in a text file or in a csv file ; for instance :
$ seplot data.txt
will plot the second column of file data.txt as a function of the first column.
That is equivalent to (using Python’s indexing convention starting at 0)
$ seplot data.txt x=0 y=1 out=plot.pdf
By default, seplot exports to plot.pdf, but any .pdf, .eps, or .svg filename can be specified.
But one might want to do more, for example plot a function of the input data, and plot error bars :
$ seplot data.txt x='sqrt(A[:,0])/2' dy='sqrt(y)'
You can also plot according to a condition, e.g. y>0 :
$ seplot data.txt if='y>0'
And to do a bit more, specify a style according to y values :
$ seplot data.txt if='y>0' color=red andif='y<=0' color=blue
Also, seplot supports LaTeX so you can label plots like :
$ seplot data.txt y='sin(A[:,0])' title='$\sin{x}$' xlabel='$v$ in $\mu m / s$'
You can also plot an arbitrary function y(x). For instance, to get the image above, the command was :
$ seplot data.txt y='abs(y)' title='$\sqrt{x^2}$' style=o color=blue dy=2 function='y(x)=x' ylabel='velocity $v$ (m s$^-1$)' xlabel='time $t$ (s)'
You can also use seplot from Python :
import seplot
plot=seplot.Splotter(xlabel='$v$')
plot.add_plot(file='data.txt',cond='A[:,0]>0')
plot.make_and_save(out='nice_data_plot.svg')
For all the possibilities, see the README.
