def draw_box_lines(self, ax, data, support, density, center):
"""Draw boxplot information at center of the density."""
# Compute the boxplot statistics
q25, q50, q75 = np.percentile(data, [25, 50, 75])
whisker_lim = 1.5 * iqr(data)
h1 = np.min(data[data >= (q25 - whisker_lim)])
h2 = np.max(data[data <= (q75 + whisker_lim)])
# Draw a boxplot using lines and a point
if self.orient == "v":
ax.plot([center, center], [h1, h2],
linewidth=self.linewidth,
color=self.gray)
ax.plot([center, center], [q25, q75],
linewidth=self.linewidth * 3,
color=self.gray)
ax.scatter(center,
q50,
zorder=3,
color="white",
edgecolor=self.gray,
s=np.square(self.linewidth * 2))
else:
ax.plot([h1, h2], [center, center],
linewidth=self.linewidth,
color=self.gray)
ax.plot([q25, q75], [center, center],
linewidth=self.linewidth * 3,
color=self.gray)
ax.scatter(q50,
center,
zorder=3,
color="white",
edgecolor=self.gray,
s=np.square(self.linewidth * 2))
def _freedman_diaconis_bins(a):
"""Calculate number of hist bins using Freedman-Diaconis rule."""
# From https://stats.stackexchange.com/questions/798/
a = np.asarray(a)
if len(a) < 2:
return 1
h = 2 * iqr(a) / (len(a)**(1 / 3))
# fall back to sqrt(a) bins if iqr is 0
if h == 0:
return int(np.sqrt(a.size))
else:
return int(np.ceil((a.max() - a.min()) / h))