After two hours solid of banging my head against a wall trying to get matplotlib do what I wanted, I was able to go from this LibreOffice graph:

To something a little nicer:

It’s still ugly, and confusing, but it’s a lot closer to what I wanted. The IPython environment is a interesting way of working with data too. I will have to play around with it more in the future.

Awful, awful Python code

(Really. Everything below is probably wrong)

%matplotlib inline
import matplotlib.pyplot as plt
from matplotlib.dates import strpdate2num
import matplotlib.dates as mdates
import numpy
import csv

filename = 'c:\\Users\Matthew\\adsl.csv'

rows = ("\t".join(i) for i in csv.reader(open(filename, 'r'), quotechar='"'))
converters = {0: strpdate2num('%Y/%m/%d %H:%M:%S')}
(x, sync_up, sync_down, snr_up, snr_down, attune_up, attune_down) = numpy.genfromtxt(rows, delimiter="\t", skip_header=1, converters=converters, unpack=True)

fig = plt.figure()

ax = fig.add_subplot(111)

# Configure x-ticks
# ax.set_xticks(x) # Tickmark + label at every plotted point
ax.xaxis.set_major_formatter(mdates.DateFormatter('%d/%m/%Y %H:%M'))

ax.plot_date(x, sync_up, '--', c='r', label='Sync(up)') # ls='-', marker='o')
ax.plot_date(x, sync_down, '--', c='g', label='Sync(down)') # ls='-', marker='o')
ax.set_title('ADSL2+ Line Quality')
ax.set_ylabel('Speed (kbps)')

ax.legend(bbox_to_anchor=(1.05, 1), loc=2)

highlight_start = x[212]
highlight_end = x[220]

ax.axvspan(highlight_start, highlight_end, facecolor='red', alpha=0.1)

ax2 = ax.twinx()
ax2.plot_date(x, snr_up,'-', c='r', label='SNR(up)')
ax2.plot_date(x, snr_down, '-', c='g', label='SNR(down)')
ax2.plot_date(x, attune_up, '-', c='c', label='Attenuation(up)')
ax2.plot_date(x, attune_down, '-', c='m', label='Attenuation(down)')
ax2.set_ylabel('Decibel (db)')

ax2.legend(bbox_to_anchor=(1.05, 0.80), loc=2)