The two basic goals of data mining are predicting and describing data

The predictions mainly include classification-dividing the sample into one of several predefined classes, regression-mapping the Crown Proxy network sample to a real-valued predictor variable; The description mainly includes clustering-dividing the sample into different classes (no predefined classes), and association rule Discovery-discovering the correlations of the different features in the dataset. Other articles in this series will explain these work in depth, if the reader is the first to contact these concepts please do not tangle.

The list of brands is reduced by default, and clicking the "Show All Brands" button shows all brands, while the list highlights the name of the recommended brand, and the text in the button becomes "thin display brand". Click "Refine display brand" again to return to the initial page.

Unlike a value type, a reference type is assigned to a variable, a constant, or is passed to a function, and the operation is not a copy of it. Therefore, referring to an existing instance itself instead of its copy

Identity operator

Because a class is a reference type, there may be multiple constants and variables that reference a class instance at the same time in the background. It would be helpful to be able to determine whether two constants or a variable references the same class instance. In order to achieve this, Swift has built two identity operators:

The two basic goals of data mining are predicting and describing data