Tag：Significance

Time：2021119
Author: a cat that wants to flyReviewer: Tong MengEdit: Angelica Box graph is one of the most common graphs in statistics. This article will describe how to simply compare the average values of two or more groups and add significance markers. Generally, it can be divided into four categories according to the value of significance […]

Time：20211026
Many things can be better improved and enhanced only after understanding the internal principle and operation mechanism. However, some things are born “incomprehensible”, such as convolutional neural network (CNN). So how to further improve it? CNN has excellent practical performance in practical tasks such as image classification and target detection. Therefore, it has been introduced […]

Time：2021722
1. Introduction of regression model Let’s take a look at the regression model. The following explanation comes from Baidu Encyclopedia: Regression model is a predictive modeling technology, which studies the relationship between dependent variable (target) and independent variable (predictor). This technique is usually used forForecast analysisTime series model and the relationship between variablescausal relationship。 The […]

Time：2021721
01. Preface In front of us, we talked about univariate linear regression. If you haven’t seen it, you can take a look at it first: [univariate linear regression analysis]. In this article, let’s talk about multiple linear regression. Univariate linear regression means that there is only one X in the independent variable, while multivariate linear […]

Time：2021621
SQL update diag_product_list_ios as a join (select soft_package_id,soft_name from diag_product_list_ios where pdt_code=’ThinkDiag’ ) as b on a.soft_package_id=b.soft_package_id set a.soft_name=b.soft_name where a.pdt_code=’EASYDIAG4′ and a.soft_name is null mysql Synchronous update This work adoptsCC agreementReprint must indicate the author and the link of this article The meaning of life lies in the courage to bear the meaninglessness of […]

Time：202142
In this series, we will discuss Linux performance measurement and how to measure it correctly. Linux performance is a very broad topic, so we will focus on the four main resources that usually improve system performance — CPU, memory, disk storage and network.As far as disks are concerned, there are actually two things you need […]

Time：202131
01. Preface We talked about multiple linear regression. In this article, let’s talk about gradual regression. What is stepwise regression? It’s literally a stepbystep return. We know that the element in multiple regression refers to the independent variable, and multiple variables are multiple independent variables, namely multiple X. One of the questions we need to […]

Time：2021222
In practice, full table scanning is always avoided, so slow table scanning is avoidedsqlIndex on some fields in. The significance of index building is that the original operation of scanning and operation in the table is executed in the index to reduce the number of scanning rows in the table, so the query speed is […]

Time：2021128
Last time I wrote the confidence level and confidence interval in statistics, the article has a good response. This time I’ll try to write the hypothesis test in statistics. The core of hypothesis testing is actually the method of disprovement. Proof to the contrary is a concept in mathematics, that is, if you want to […]

Time：20201023
AuthorCompile  VKSource  analytics vidhya introduce Test is one of the most basic concepts in statistics. Not only in data science, hypothesis testing is very important in various fields. Want to know how to do it? Let’s take an example. Now there’s a lifebuoy shower gel. Shower Gel manufacturers claim it kills 99.9% of […]

Time：202092
This article starts with WeChat official account of vivo Internet technology.Link: https://mp.weixin.qq.com/s/mO5MdwG7apD6RzDhFwZhogAuthor: duzhimin More and more companies are trying abtest, either building their own systems or relying on thirdparty systems. So what are the necessary basic knowledge when we conduct abtest? How to carry out AB experiment step by step? In this paper, we will […]

Time：202092
PHP common checks #Android or not function is_android() { return stripos($_SERVER[‘HTTP_USER_AGENT’], “Android”); } #IPhone function is_iphone() { return stripos($_SERVER[‘HTTP_USER_AGENT’], “iPhone”); } //Determine whether Ajax request function isAjax() { return (isset($_SERVER[‘HTTP_X_REQUESTED_WITH’]) && ($_SERVER[‘HTTP_X_REQUESTED_WITH’] == ‘XMLHttpRequest’)); } Regular rules in PHP #ID card verification $preg = ‘/^(\d{15}$^\d{18}$^\d{17}(\dXx))$/’; if (!preg_match($preg, $idNumber)) { return false; } #Mobile phone number […]