monitor/extra/plotting.py

   1 #!/usr/bin/env python
   2 # -*- coding: utf-8 -*-
   3 #
   4 # Server monitoring system
   5 #
   6 # Copyright © 2011 Rodrigo Eduardo Lazo Paz
   7 #
   8 # This program is free software: you can redistribute it and/or modify
   9 # it under the terms of the GNU General Public License as published by
  10 # the Free Software Foundation, either version 3 of the License, or
  11 # (at your option) any later version.
  12 #
  13 # This program is distributed in the hope that it will be useful,
  14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 # GNU General Public License for more details.
  17 #
  18 # You should have received a copy of the GNU General Public License
  19 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 #
  21
  22
  23 """Data Plotting routines.
  24
  25 Requires matplotlib with cairo support built-in."""
  26
  27
  28 __author__ = "rlazo.paz@gmail.com (Rodrigo Lazo)"
  29 __version__ = 0.2
  30
  31
  32 import matplotlib
  33 matplotlib.use('cairo.png')
  34
  35 from datetime import datetime
  36 import matplotlib.pyplot as plot
  37 from pylab import epoch2num
  38 import os.path
  39
  40
  41 IMAGE_DPI = 80
  42
  43
  44 # TODO (09/20): Make this functions more generic and clear, right now
  45 #               they depend on `DataEntry` objects.
  46 def new_multigraph(data_dict, title, target_dir=""):
  47     """Creates a single image with multiple plots.
  48
  49     `data_dict` must be in the form:
  50     {'key': `DataEntry`, 'key': `DataEntry`}
  51
  52     'key' will be the label of the plot.
  53
  54     Arguments:
  55     - `data_dict`: Dict, data source.
  56     - `title`: String, title of the plot.
  57     - `target_dir`: String, path where to write the image file.
  58
  59     Returns:
  60       String, filename of the generated image.
  61     """
  62     for name, values in data_dict.iteritems():
  63         data = values.get_all()
  64         xs = [x.timestamp for x in data]  # pylint: disable=C0103
  65         ys = [x.value for x in data]      # pylint: disable=C0103
  66         plot.plot_date(epoch2num(xs),
  67                        ys, '-', label=name)
  68     plot.title(title)
  69     plot.xlabel("timestamp")
  70     plot.margins(0.1)
  71     plot.legend(loc="upper right")
  72     plot.grid(True)
  73     filename = "%s-%s.png" % (title.replace(' ', '_'),
  74                               datetime.now().strftime("%Y%m%d_%H%M%S"))
  75     target_file = str(os.path.join(target_dir, filename))
  76     plot.savefig(target_file, dpi=IMAGE_DPI)
  77     plot.clf()
  78     return filename, target_file
  79
  80
  81 def new_graph(data_lst, title, target_dir):
  82     """Creates a single image with multiple plots.
  83
  84     `data_lst` must be a list of pairs in the form:
  85     [(x, y), (x,y), (x,y)]
  86
  87     Arguments:
  88     - `data_lst`: Iterable, data source.
  89     - `title`: String, title of the plot.
  90     - `target_dir`: String, path where to write the image file.
  91
  92     Returns:
  93       String, filename of the generated image.
  94     """
  95     xs = [x[0] for x in data_lst]  # pylint: disable=C0103
  96     ys = [x[1] for x in data_lst]  # pylint: disable=C0103
  97     plot.plot_date(epoch2num(xs), ys, '-')
  98     plot.title(title)
  99     plot.xlabel("timestamp")
 100     plot.margins(0.1)
 101     plot.legend(loc="upper right")
 102     plot.grid(True)
 103     now_str = datetime.now().strftime("%Y%m%d_%H%M%S")
 104     filename = "%s-%s.png" % (title.replace(' ', '_'), now_str)
 105     target_file = str(os.path.join(target_dir, filename))
 106     print now_str, filename, target_file
 107     plot.savefig(target_file, dpi=IMAGE_DPI)
 108     plot.clf()
 109     return filename, target_file