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"""
==============================================
Plot randomly generated multilabel dataset
==============================================
This illustrates the :func:`~sklearn.datasets.make_multilabel_classification`
dataset generator. Each sample consists of counts of two features (up to 50 in
total), which are differently distributed in each of two classes.
Points are labeled as follows, where Y means the class is present:
===== ===== ===== ======
1 2 3 Color
===== ===== ===== ======
Y N N Red
N Y N Blue
N N Y Yellow
Y Y N Purple
Y N Y Orange
Y Y N Green
Y Y Y Brown
===== ===== ===== ======
A star marks the expected sample for each class; its size reflects the
probability of selecting that class label.
The left and right examples highlight the ``n_labels`` parameter:
more of the samples in the right plot have 2 or 3 labels.
Note that this two-dimensional example is very degenerate:
generally the number of features would be much greater than the
"document length", while here we have much larger documents than vocabulary.
Similarly, with ``n_classes > n_features``, it is much less likely that a
feature distinguishes a particular class.
"""
import matplotlib.pyplot as plt
import numpy as np
from sklearn.datasets import make_multilabel_classification as make_ml_clf
COLORS = np.array(
[
"!",
"#FF3333", # red
"#0198E1", # blue
"#BF5FFF", # purple
"#FCD116", # yellow
"#FF7216", # orange
"#4DBD33", # green
"#87421F", # brown
]
)
# Use same random seed for multiple calls to make_multilabel_classification to
# ensure same distributions
RANDOM_SEED = np.random.randint(2**10)
def plot_2d(ax, n_labels=1, n_classes=3, length=50):
X, Y, p_c, p_w_c = make_ml_clf(
n_samples=150,
n_features=2,
n_classes=n_classes,
n_labels=n_labels,
length=length,
allow_unlabeled=False,
return_distributions=True,
random_state=RANDOM_SEED,
)
ax.scatter(
X[:, 0], X[:, 1], color=COLORS.take((Y * [1, 2, 4]).sum(axis=1)), marker="."
)
ax.scatter(
p_w_c[0] * length,
p_w_c[1] * length,
marker="*",
linewidth=0.5,
edgecolor="black",
s=20 + 1500 * p_c**2,
color=COLORS.take([1, 2, 4]),
)
ax.set_xlabel("Feature 0 count")
return p_c, p_w_c
_, (ax1, ax2) = plt.subplots(1, 2, sharex="row", sharey="row", figsize=(8, 4))
plt.subplots_adjust(bottom=0.15)
p_c, p_w_c = plot_2d(ax1, n_labels=1)
ax1.set_title("n_labels=1, length=50")
ax1.set_ylabel("Feature 1 count")
plot_2d(ax2, n_labels=3)
ax2.set_title("n_labels=3, length=50")
ax2.set_xlim(left=0, auto=True)
ax2.set_ylim(bottom=0, auto=True)
plt.show()
print("The data was generated from (random_state=%d):" % RANDOM_SEED)
print("Class", "P(C)", "P(w0|C)", "P(w1|C)", sep="\t")
for k, p, p_w in zip(["red", "blue", "yellow"], p_c, p_w_c.T):
print("%s\t%0.2f\t%0.2f\t%0.2f" % (k, p, p_w[0], p_w[1]))
|
