Question

I have to plot an histogram in logarithmic scale on both axis using gnuplot. I need bins to be equally spaced in log10. Using a logarithmic scale on the y axis isn’t a problem. The main problem is creating the bin on the x axis. For example, using 10 bins in log10, first bins will be [1],[2],[3]….[10 – 19][20 – 29]…..[100 190] and so on. I’ve searched on the net but I couldn’t find any practical solution. If realizing it in gnuplot is too much complicated could you suggest some other software/language to do it?

As someone asked I will explain more specifically what I need to do. I have a (huge) list like this:

1   14000000
2   7000000
3   6500000
.
.
.
.
6600    1
8900    1
15000   1
19000   1

It shows, for example, that 14 milions of ip addresses have sent 1 packet, 7 milions 2 packets…. 1 ip address have sent 6600 packets, … , 1 ip address have sent 19000 packets. As you can see the values on both axes are pretty high so I cannot plot it without a logarithmic scale.

The first things I tried because I needed to do it fast was plotting this list as it is with gnuplot setting logscale on both axes using boxes. The result is understandable but not too appropriate. In fact, the boxes became more and more thin going right on the x axis because, obviously, there are more points in 10-100 than in 1-10! So it became a real mess after the second decade.

Answer 1

Have you tried Matplotlib with Python? Matplotlib is a really nice plotting library and when used with Python’s simple syntax, you can plot things quite easily:

import matplotlib.pyplot as plot

figure = plot.figure()
axis = figure.add_subplot(1 ,1, 1)
axis.set_yscale('log')

# Rest of plotting code