For sklearn.svm in "dual_coef_" understanding

1, the expression of the decision-making function

  • Formula:

    in which:

2, SVM after training, the resulting "dual_coef_"

  • In fact, "dual_coef_" is "ai * yi" collection, namely:

3. Verify

  • Linear SVM model used here to verify
from sklearn import svm
from Orange.data import Table
import numpy as np

data = Table("iris2")

model = svm.SVC(C=1.0, kernel='linear')
model.fit(data.X, data.Y)


print(model.dual_coef_)
print(model.support_vectors_)

# 计算法向量  累加(a[i]*y[i]*sv[i])  dual_coef = 累加(a[i]y[i])
x = np.dot(model.dual_coef_ , model.support_vectors_)
print(x[0])
print(model.coef_[0])


model.dual_coef_:

model.support_vectors_:

x[0]

model.coef_[0]:

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Origin www.cnblogs.com/komean/p/11008586.html