0
S
T
S + T
Sum
Q + S
R + T
P = q + S + T + R
Now let's look at the similarity: Q and T. That is, similarity measurement: d (I, j) = (q + T)/P = (q + T)/(q + S + T + r)
Conversely, the opposite sex is a different measurement value .. That is, S and R, D (I, j) = (S + r)/P
Of course, what we calculate is symmetric binary. What is a symmetric Binary Attribute? Both are meaningful and important in reality.
Next, asymmetric binary similarity is assumed
1. Data Mining classification: From the Perspective of data analysis, data mining can be divided into two types: Descriptive data mining-to express the existence of meaningful propertie
independent and has no correlation.If that is less than 0, the description is negatively correlated, and one value increases by another.Note that correlations do not imply causality, and if A and B are relevant, it does not mean that a causes B or B to cause a.3. Covariance of numeric dataCovariance and variance are two similar measures that evaluate how the two properties change together. The mean values of A and B are also known as expectations.The covariance of A and B is defined as: For
The previous series has talked about various kinds of knowledge, including drawing curves, scatter plots, power distributions and so on, and it becomes very important how to fit a straight line in a pile of scatter plots. This article mainly describes the Curve_fit function that calls the SCIPY extension package to achieve the curve fitting, simultaneously calculates the fitting function, the parameter and so on. Hope the article is helpful to you, if there are errors or deficiencies in the arti
Data Mining data analysis for online games Roadmap order:1) Build the basic data Warehouse;2) Wrong the user system:A) identification of the authenticity of user informationb) User grouping, segmenting the whole user into groups with specific attribute characteristics3) Organize da
Common Data Mining MethodsBasic Concepts
Data Mining is fromMassive, incomplete, noisy, and fuzzyThe process of extracting potentially useful information and knowledge hidden in the data that people do not know beforehand. Specifically, as a broad application-oriented cross-
the required package again.4, after learning the introductory book, you need to learn how to use Python to do data analysis, recommend a book: using Python for data analysis, this book mainly introduces the data analysis of several commonly used modules: NumPy, pandas, Matplotlib, and data preprocessing required
In various data mining algorithms, association rule mining is an important one, especially influenced by basket analysis. association rules are applied to many real businesses, this article makes a small Summary of association rule mining. First, like clustering algorithms, association rule
Data mining refers to the non-trivial process of automatically extracting useful information hidden in data from data collection, which is represented by rules, concepts, laws and patterns, etc.2.1 Development History of data mining
1 Introduction
With the increasing popularity of the Internet, various forms of information generation and collection have led to the explosion. The competitive trend of modern society requires real-time and deep analysis of this information, although there is now a more powerful information storage and retrieval system. But users are becoming more and more difficult to analyze and use the information they have. How to effectively organize and utilize a large amount of information, so that user
whitespace (" product_id "CHAR (5) enclosed by X ' 7C '," Sales_da TE "DATE" dd-mon-yyyy AD HH24:MI:SS "enclosed by X ' 7C '," Sales_cost "CHAR (3)
Enclosed by x ' 7C ', "STATUS" CHAR (8) enclosed by x ' 7C ') This proves that the table structure in all the control files is the structure of the whole table, not the partition table, in the actual process, you can consider the swap partition to implement -----------------Tips--------------------
operation is risky, hands-on need to be cautious
O
hypothesis is obviously too strong,This is not necessarily the case. The use of the mean variance method also has similar problems. Therefore, the data normalization this step is not necessary to do, the specific problem to be seen. Normalization first in the case of a very large number of dimensions, you can prevent a certain dimension or some of the dimensions of the data impact too much, and then the pr
Most data mining algorithms rely on numeric or categorical features, extracting numeric and categorical features from a data set, and selecting the best features.Features can be used for modeling, and models represent reality in an approximate way that machine mining algorithms can understandAnother advantage of featur
Some people work very original, there are some very new things every year. Some people have a lot of articles, but mainly follow others ' work. There are many paper machine in the database field. In some places, the whole group is a big paper machine.Personal feeling database researchers tend to think of data mining as a sub-domain of a database, and thus have lower rating for
1. Differences between statistics and data mining: Statistics mainly uses probability theory to establish mathematical models. It is one of the common mathematical tools used to study random phenomena. Data Mining analyzes a large amount of data, discovers internal links a
Some time ago, because the project used the algorithm of sequential mining, brother recommended me to use SPMF. Make a note here.
Let's start with a brief introduction to SPMF:
SPMF is an open source data mining platform with Java development.
It provides 51 data m
Reference:http://www.52nlp.cn/python-%e7%bd%91%e9%a1%b5%e7%88%ac%e8%99%ab-%e6%96%87%e6%9c%ac%e5%a4%84%e7%90%86 -%e7%a7%91%e5%ad%a6%e8%ae%a1%e7%ae%97-%e6%9c%ba%e5%99%a8%e5%ad%a6%e4%b9%a0-%e6%95%b0%e6%8d%ae%e6%8c%96%e6%8e% 98A Python web crawler toolsetA real project must start with getting the data. Regardless of the text processing, machine learning and data mining
you can also use regular expression matching, Which is omitted here.
Next is the region, which is located in the "coordinate" attribute. It is not convenient to use regular expression matching. Therefore, we use the series partitioning method, that is, to split this attribute by characters and extract items with fixed positions. Through observation, you can use symbols to separate them, which is exactly the same as 4th items.
Similarly, you can extract the name of a residential area. The only
]} = \frac{|x_{if}-x_{jf}|} {\max_{h} x_{hf}-\min_{h} X_{HF} $, where h passes all non-missing objects of property F.
F is nominal or two yuan: if \ (x_{if} = x{jf}\), then \ (d_{ij}^{[f]}=0\), otherwise take 1.
F is ordinal: computes the rank \ (r_{if}\) and \ (z_{if} = \frac{r_{if}-1}{m_f-1}\)and then processes it as a numeric attribute.
Cosine similarityTo compare documents, each document is represented by a so-called word frequency vector, usually very long and sparse, and the t
With the advent of the cloud era and the introduction of SAAS concepts, more and more enterprises are choosing to provide SaaS application services through Internet platforms such as SaaS application providers and carriers, the data volume of SAAS applications is growing at the TB level. Different SaaS application systems provide different data structures, including text, graphics, and even small databases;
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