• Data mining and life

Time：2021-12-29

Data mining and life preface The purpose of writing this article is to introduce the company’s colleagues to the basic knowledge of data mining, in order to enhance everyone’s understanding and interest in data mining, apply this technology to work and life, give play to the collective wisdom and add data mining application scenarios for […]

• Uistackview linear document flow layout

Time：2021-12-26

overview Uistackview provides automatic layout and automatic scaling features for single row or single column. The feature provided by uiscrllview is that the contentsize is greater than frame Size can slide. In theory, the linear document flow layout can be realized by combining the two characteristics, and the layout is arranged from top to bottom. […]

• Exercises in Chapter 2 of statistical learning methods

Time：2021-12-19

Exercise 2.1 The function of the perceptron model is expressed as$$f(x) = sign(w*x+b)$$ Among them,$$sign(x)=\begin{cases} +1, & x \geq 0 \\ -1, & x < 0 \end{cases}$$ Tabulate XOR relationships $$(x_1,x_2)$$ $$y$$ (0,0) 0 (0,1) 1 (1,0) 1 (1,1) 0 Suppose there is such a hyperplane$$w*x+b=0$$The XOR relationship can be separated. It should meet the […]

• Polynomial regression, local regression, kernel smoothing and smoothing spline regression models in R language

Time：2021-12-14

Original link:http://tecdat.cn/?p=20531 Original source:Tuo end data tribal official account === In the standard linear model, we assume。 When the linear assumption cannot be satisfied, other methods can be considered. polynomial regression The extension may assume some polynomial functions, Similarly, in the standard linear model method (conditional normal distribution using GLM), the parametersCan be obtained using […]

• What is an activation function?

Time：2021-12-11

Presumably, children’s shoes who have been exposed to neural networks must have heard a term: activation function, but is activation function a god horse? Let’s start today 1. Basic knowledge points Firstly, from the perspective of machine learning, neural network can be regarded as a nonlinear model. Its basic unit is neurons with nonlinear activation […]

• Zero foundation “machine learning” self study notes | Note7: logical regression

Time：2021-12-7

logic.jpeg Write in front This series is my personal notes when I taught myself [machine learning]. There may be many mistakes in the learning process. I hope all readers will give me some advice. This series is based onTeacher Wu Enda’s [“machine learning” course]As the key link, supplemented byHuang Haiguang’s [personal notes of Stanford University […]

• Hengyuan cloud_ Cifar-10 dataset practice: building resnet18 neural network

Time：2021-12-6

Article source|Hengyuan cloud community Original address|Dataset practice Original author | mathor To tell you the truth, Xiaobian, I admire mathor, the big man in the platform community! No, today I’ll share with you the notes of the big man’s paper. Let’s see if the next content has the knowledge you need! Start of text: If […]

• How R language uses latent category mixed effect model (LCMM) to analyze depressive symptoms

Time：2021-12-1

Original link:http://tecdat.cn/?p=22206 Model background Each dynamic phenomenon can be represented by a latent process (Λ (T) To describe the evolution of this latent process in a continuous time T. when modeling the flag variable of repeated measurement, we usually do not regard it as a latent process with error measurement. However, this is the basic […]

• R language for data structure transformation: box Cox transformation and “convex rule” transformation method

Time：2021-11-27

Original link:http://tecdat.cn/?p=22251 In linear regression, if the data does not obey the normal distribution, it will bring errors to the results of the least squares estimation coefficients of linear regression, so it is necessary to structurally transform the data. When discussing the transformation in regression model, we usually simply use box Cox transformation, or local […]

• Tools: data analysis (thinking, skills)

Time：2021-11-21

Three kinds of core thinking: structural (pyramid model, core argument, structural disassembly, MECE, verification), formulaic (addition, subtraction, multiplication and division), operational (distinguishing phenomena / results, often places that cannot be considered) Eight thinking skills: quadrant method, multidimensional method (grouping / group, Simpson paradox, drill down), hypothesis method, index method (linear weighting, inverse proportion, log), 28 […]

• R language used locally weighted regression (LOWESS) to diagnose logistic logistic regression and analyze residual

Time：2021-11-21

Original link:http://tecdat.cn/?p=22328  At present, regression diagnosis is not only used for the diagnosis of general linear models, but also gradually extended to the field of generalized linear models (such as logistic regression models). However, there are still many problems in the popularization and application because the assumptions of residual distribution between general linear models and […]

• Tikv source code analysis series – lease read

Time：2021-11-16

This series of articles is mainly aimed at tikv community developers, focusing on tikv system architecture, source code structure and process analysis. The purpose is to enable developers to have a preliminary understanding of the tikv project and better participate in the development of tikv. This article is the fifth chapter of this series. Author: […]