Pattern Recognition (iii) the similarity measure

2.2.2 Similarity Measure :
Measure the basis of: the direction of two vectors as a basis for similar consideration whether the vector length is not important:
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1. The angle similarity coefficient (cosine)
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Note: Scaling rotation and scale invariant coordinate system is but in general linear transformation and coordinate translation is not invariant.
2. The correlation coefficient
it is actually a vector of the cosine of the angle of the data center.
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Note: correlation coefficients is (-1, 1) - 1 is substantially related, related to almost 1.
2.2.3 match measure
as measure only two states (0,1), matching measure used. 0 indicates no such feature, this feature 1 expressed. So called binary feature.
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For binary n-dimensional feature vector similarity measure can be defined as follows:
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(. 1) Measure the Tanimoto
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Example:
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(2) Measure Rao:
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Note: the number of feature number (1-1) and the selected matching feature ratio.
For example:
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(3) the simple matching coefficient
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Note: The molecule of formula (1-1) wherein the number of matching the number of (0-0) and matching features, the denominator is the number of features considered.
Example:
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(. 4) DIEC coefficient
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(5) Kulzinsky coefficient
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2.3 class definitions:
For a set S to be classified, the classification requirements of various types S1, S2, S3, SN satisfied:
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Definition 1:
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Definition 2:
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Definition 3:
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Origin blog.csdn.net/DOUBLE121PIG/article/details/93610605