Discrete histogram

plot_utils.discrete_histogram(x, fig=None, ax=None, figsize=(5, 3), dpi=100, color=None, alpha=None, rot=0, logy=False, title=None, xlabel=None, ylabel='Number of occurrences', show_xticklabel=True)[source]

Plot a discrete histogram based on the given data x, such as below:

N ^
  |
  |           ____
  |           |  |   ____
  |           |  |   |  |
  |    ____   |  |   |  |
  |    |  |   |  |   |  |
  |    |  |   |  |   |  |   ____
  |    |  |   |  |   |  |   |  |
  |    |  |   |  |   |  |   |  |
 -|--------------------------------------->  x
        x1     x2     x3     x4    ...

In the figure, N is the number of occurences for x1, x2, x3, x4, etc. And x1, x2, x3, x4, etc. are the discrete values within x.

Parameters:
  • x (list, numpy.ndarray, pandas.Series, or dict) – Data to be visualized. If x is a list, numpy arrary, or pandas Series, the content of x is analyzed and counts of x’s values are plotted. If x is a dict, then x’s keys are treated as discrete values and x’s values are treated as counts.

  • fig (matplotlib.figure.Figure or None) – Figure object. If None, a new figure will be created.

  • ax (matplotlib.axes._subplots.AxesSubplot or None) – Axes object. If None, a new axes will be created.

  • figsize ((float, float)) – Figure size in inches, as a tuple of two numbers. The figure size of fig (if not None) will override this parameter.

  • dpi (float) – Figure resolution. The dpi of fig (if not None) will override this parameter.

  • color (str, list<float>, or None) – Color of bar. If None, the default color (muted blue) is used.

  • alpha (float or None) – Opacity of bar. If None, the default value (1.0) is used.

  • rot (float or int) – Rotation angle (degrees) of X axis label. Default = 0 (upright label).

  • logy (bool) – Whether or not to use log scale for the Y axis.

  • title (str) – The title of the plot.

  • xlabel (str) – The X axis label.

  • ylabel (str) – The Y axis label.

  • show_xticklabel (bool) – Whether or not to show the X tick labels (the names of the classes).

Returns:

  • fig (matplotlib.figure.Figure) – The figure object being created or being passed into this function.

  • ax (matplotlib.axes._subplots.AxesSubplot) – The axes object being created or being passed into this function.

  • value_count (pandas.Series) – The counts of each discrete values within x (if x is an array) with each values sorted in ascending order, or the pandas Series generated from x (if x is a dict).

Notes

References:

http://pandas.pydata.org/pandas-docs/stable/generated/pandas.Series.plot.html http://pandas.pydata.org/pandas-docs/version/0.18.1/visualization.html#bar-plots

See also

plot_ranking

Plot bars showing the ranking of the data