In the latest project, we need to use SMS Verification Code to send short messages. After searching the Internet for half a day, we couldn't find a satisfactory one, so we wrote one ourselves. jquery's packaged countdown plug-in for sending mobile phone verification codes uses cookie to prevent page refresh. 实现思路： 1.实现点击按钮，对手机号进行
pip can easily install, uninstall and manage Python packages. virtualenv can establish multiple independent virtual environments, each with its own python interpreter and its own package package, which do not affect each other. pip and virtualenv can work together well, and it is very convenient to use both tools at the same time.pip is usually installed first. After installation, pip install virtualenvcan automatically download and install virtualenv from the internet.
form of cross-validation K-fold cross-validation, the initial sample is divided into K sub-samples, a single sub-sample is retained as the data of the validation model, and the other K-1 samples are used for training.Cross-validation is repeated for k times, and each sub-sample is verified once. The results of average k times or other combination methods are used to finally obtain a single estimation.The advantage of this method is that randomly
VirtualBox is a very excellent virtual machine program produced by SUN. The version is also very complete. You can find the version suitable for various operating system platforms on the official website.Here I will give you a general explanation of the network configuration and application of VBox.VirtualBox provides four network access modes, which are:1. NAT,Network Address Translation Mode (NAT)2. Bridged Adapter Bridge pattern3. Internal internal network mode4.
Copyright Statement: This article is original. Please indicate the source for reprinting. 1. Principle 1.1 concept Cross-validation is mainly used in model training or modeling applications, such as classification prediction, PCR, PLS regression modeling, etc.In a given sample space, most samples are taken as training sets to train the model, and the remaining small samples are predicted using the newly established model, and the prediction error or prediction accuracy of
(1) Arithmetic Operator Java运算符 算术运算符 代数表达式 Java表达式 加 + a+1 a+1 减 - a-b a-b 乘 * ab a*b 除 / a/b a/b 求模/余 % a mod b a%b Note: 1 > there is no power arithmetic operator in Java 2 > there are no operators in
Just like learning the operating system, after installing rac clusters, the first thing to do is to learn how to start and shut down rac. Generally, there are three ways to start and shut down RAC: sqlplus,srvctl, dbconsole or oracle grid control. This section briefly introduces the use of srvctl to start and shut down RAC database clusters! Use crs_stat command to query whether asm instance, listener, Global Service Daemon,