Created
December 30, 2018 03:55
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Python Rosenblatt Perceptron
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import matplotlib.pyplot as plt | |
import numpy as np | |
X = np.array([ | |
[0.8, 0.4], | |
[0.3, 0.1], | |
[0.8, 0.8], | |
[0.4, 0.6], | |
[0.6, 0.8], | |
[0.4, 0.2], | |
[0.4, 0.5], | |
]) | |
Y = np.array([0, 0, 1, 1, 1, 0, 1]) | |
def plot_points(X, Y, ax): | |
for i, x in enumerate(X): | |
ax.scatter(x[0], x[1], s=120, | |
marker=('_' if Y[i] <= 0 else '+'), linewidths=2, | |
c=('r' if Y[i] <= 0 else 'b') | |
) | |
fig, ax = plt.subplots(figsize=(6, 6)) | |
plot_points(X, Y, ax) | |
def update(X, Y): | |
w = np.zeros(X.shape[1]+1) | |
epochs = 100 | |
#fig, axes = plt.subplots(figsize=(5, 30), nrows=epochs, ncols=1) | |
for e in range(epochs): | |
for x, y in zip(X, Y): | |
pred = np.where((np.dot(w[:2], x)+w[2]) >= 0.0, 1, 0) | |
w[:2] += eta*(y-pred) * x | |
w[2] += eta*(y-pred) | |
return w | |
def predict(w, x): | |
return np.where((np.dot(w[:2], x)+w[2]) > 0.0, 1, 0) | |
w = update(X, Y) | |
for a in range(0, 10): | |
for b in range(0, 10): | |
i, j = a/10, b/10 | |
p = predict(w, [i, j]) | |
plt.scatter(i, j, s=120, marker=('_' if p <= 0 else '+'), linewidths=2, | |
c=('r' if p <= 0 else 'b') | |
) |
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(X, y):
hyperplane: