Many machine-learning algorithms must have options on the identical scale.
There are diffident sorts of characteristic scaling strategies that we are able to select in numerous situations. They’ve completely different (technical) names. The time period Characteristic Scaling merely refers to any of these strategies.
Matters
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1. Characteristic scaling in numerous situationsa. Characteristic scaling in PCA
b. Characteristic scaling in k-means
c. Characteristic scaling in KNN and SVM
d. Characteristic scaling in linear fashions
e. Characteristic scaling in neural networks
f. Characteristic scaling within the convergence
g. Characteristic scaling in tree-based algorithms
h. Characteristic scaling in LDA
2. Characteristic scaling strategies
a. Standardization
b. Min-Max Scaling (Normalization)
c. Robust Scaling
d. Mean Normalization
e. Maximum Absolute Scaling
f. Vector Unit-Length Scaling
3. Characteristic scaling and distribution of information
4. Knowledge leakage when characteristic scaling
5. Abstract of characteristic scaling strategies
- Characteristic scaling in PCA: In principal element evaluation, PCA parts are extremely delicate to the relative ranges of the unique options, if they aren’t measured on the identical scale. PCA tries to decide on the parts that maximize the variance of the information. If the maximization of varied happens as a consequence of greater ranges of some options, these options could are inclined to dominate the PCA course of. On this case, the true variance will not be captured by the parts. To keep away from this, we typically carry out characteristic scaling earlier than PCA. Nevertheless, there are two exceptions. If there is no such thing as a important distinction within the scale between the options, for instance, one characteristic ranges between 0 and 1 and one other ranges between 0 and 1.2, we don’t must carry out characteristic scaling though there might be no hurt if we do! Should you carry out PCA by decomposing the correlation matrix as a substitute of the covariance matrix, you don’t want to do characteristic scaling though the options usually are not measured on the identical…
