Python display specific values on x-axis using matplotlib

graph, matplotlib, python

Solution

You need to create some xdata by `np.arange()`:

import matplotlib as mpl
import numpy as np
import matplotlib.pyplot as plt

dst_ports = [22, 53223, 40959, 80, 3389, 23, 443, 35829, 8080, 4899, 21320, 445, 3128, 44783, 4491, 9981, 8001, 21, 1080, 8081, 3306, 8002, 8090]
dst_port_count = [5005, 145, 117, 41, 34, 21, 17, 16, 15, 11, 11, 8, 8, 8, 6, 6, 4, 3, 3, 3, 1, 1, 1]

fig = plt.figure(figsize=(12, 4))

# aesthetics and data
plt.grid()
x = np.arange(1, len(dst_ports)+1)
plt.bar(x, dst_port_count, align='center')
plt.xticks(x, dst_ports, rotation=45)

# labels
plt.title('Number of connections to port')
plt.xlabel('Destination Port')
plt.ylabel('Connection Attempts')

Here is the output:

Problem

I'm querying data from a simple sqlite3 DB which is pulling a list of the number of connections per port observed on my system. I'm trying to graph this into a simple bar-chart using matplotlib. Thus far, I'm using the follow code: ``` import matplotlib as mpl mpl.use('Agg') # force no x11 import matplotlib.pyplot as plt import sqlite3 con = sqlite3.connect('test.db') cur = con.cursor() cur.execute(''' SELECT dst_port, count(dst_port) as count from logs where dst_port != 0 group by dst_port order by count desc; ''' ) data = cur.fetchall() dst_ports, dst_port_count = zip(*data) #dst_ports = [22, 53223, 40959, 80, 3389, 23, 443, 35829, 8080, 4899, 21320, 445, 3128, 44783, 4491, 9981, 8001, 21, 1080, 8081, 3306, 8002, 8090] #dst_port_count = [5005, 145, 117, 41, 34, 21, 17, 16, 15, 11, 11, 8, 8, 8, 6, 6, 4, 3, 3, 3, 1, 1, 1] print dst_ports print dst_port_count fig = plt.figure() # aesthetics and data plt.grid() plt.bar(dst_ports, dst_port_count, align='center') #plt.xticks(dst_ports) # labels plt.title('Number of connections to port') plt.xlabel('Destination Port') plt.ylabel('Connection Attempts') # save figure fig.savefig('temp.png') ``` When I run the above, the data is successful retrieved from the DB and a graph is generated. However, the graph isn't what I was expecting. For example, on the x-axis, it plots all values between 0 and 5005. I'm looking for it to display only the values in dst_ports. I've tried using xticks but this doesn't work either. I've included some sample data in the above code which I've commented out that may be useful. In addition, here is an example of the graph output from the above code: And also a grpah when using xticks:

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