Pie chart

plot_utils.piechart(target_array, class_names=None, dropna=False, top_n=None, sort_by='counts', fig=None, ax=None, figsize=(3, 3), dpi=100, colors=None, display='percent', title=None, fontsize=None, verbose=True, **piechart_kwargs)[source]

Plot a pie chart demonstrating proportions of different categories within an array.

Parameters:

  • target_array (array_like) – An array containing categorical values (could have more than two categories). Target value can be numeric or texts.

  • class_names (sequence of str) – Names of different classes. The order should correspond to that in the target_array. For example, if target_array has 0 and 1 then class_names should be [‘0’, ‘1’]; and if target_array has “pos” and “neg”, then class_names should be [‘neg’,’pos’] (i.e., alphabetical). If None, values of the categories will be used as names. If [], then no class names are displayed.

  • dropna (bool) – Whether to drop NaN values or not. If False, they show up as ‘N/A’.

  • top_n (int) – An integer between 1 and the number of unique categories in target_array. Useful for preventing plotting too many unique categories (very slow). If None, plot all categories.

  • sort_by ({'counts', 'name'}) – An option to control whether the pie slices are arranged by the counts of each unique categories, or by the names of those categories.

  • 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.

  • colors (list or None) – A list of colors (can be RGB values, hex strings, or color names) to be used for each class. The length can be longer or shorter than the number of classes. If longer, only the first few colors are used; if shorter, colors are wrapped around. If None, automatically use the Pastel2 color map (8 colors total).

  • display ({‘percent’, ‘count’, ‘both’, None}) – An option of what to show on top of each pie slices: percentage of each class, or count of each class, or both percentage and count, or nothing.

  • title (str or None) – The text to be shown on the top of the pie chart.

  • fontsize (scalar or tuple/list of two scalars) – Font size. If scalar, both the class names and the percentages are set to the specified size. If tuple of two scalars, the first value sets the font size of class names, and the last value sets the font size of the percentages.

  • verbose (bool) – Whether or to show a “Plotting more than 100 slices; please be patient” message when the number of categories exceeds 100.

  • **piechart_kwargs – Keyword arguments to be passed to matplotlib.pyplot.pie function, except for “colors”, “labels”and “autopct” because this subroutine re-defines these three arguments. (See https://matplotlib.org/api/_as_gen/matplotlib.pyplot.pie.html)

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.