api programming for dummies

I. What is SVG? SVG is a 2D graphic description language released by W3C in 1999. It is a markup language based solely on XML format. The full name is extensible vector graphics, which is very different from traditional Raster graphics (JPG, PNG, GIF, etc.). No. SVG is a 2D graphics development platform. It consists of two parts: XML-based data description and The other part is a programmable API. Its key features support graphics, text, gradient fil

One: what is SVG SVG is a 1999 2D graphic description Language published by the consortium, a purely XML-based markup language, SVG The full name is a large difference between scalable vector graphics and traditional raster graphics (JPG, PNG, GIF, etc.) Don't. SVG is a 2D graphics development platform, including two parts, one is based on the XML language data description, and the other The outside part is a programmable API with key features that s

The game handles the programming development in two, has explained, in this article will explain to the keyboard simulation. The simulation of the keyboard, the system has provided a lot of API functions, here is not one to explain, only the simplest of the API functions. ///　 　　　　　　 ///　模拟键盘事件 　　　　　　 ///　 　　　　　　 ///　 　　　　　　 ///　 　　　　　　 ///　 　　　　　　 ///　 　　　　　　

);SOCKFD is a server socket descriptor that is being monitored, and addr is usually a pointer to a sockaddr_in variable that holds the client address that made the connection request the Connect () function is used to establish a TCP connection to the remote server with its function prototype:int Connect (int sockfd, struct sockaddr *serv_addr, int addrlen);int Send (int sockfd, const void *msg, int len, int flags); int recv (int sockfd,void *buf,int len,unsigned int flags);int sendto (int sockf

We create two files in the/data/join of HDFs:Upload the first file name is 1.txtContent first column is date, second column UID (normal user ID)Upload a second file name of 2.txtContent first column is date, second column UID (normal user ID)perform upload to HDFs:HDFs command-line query:Web Console Management Queries:First, set the date format on the command line:Then declare two case Class:register, LoginRead the first file (1.txt) and do the following:Take operation:This is done by reading th

Below is a look at the use of Union:Use the collect operation to see the results of the execution:Then look at the use of Groupbykey:Execution Result:The join operation is the process of a Cartesian product operation, as shown in the following example:To perform a join operation on RDD3 and RDD4:Use collect to view execution results:It can be seen that the join operation is exactly a Cartesian product operation;The reduce itself, which is an action-type operation in an RDD operation, causes the

HDFs = Mypath.getfilesystem (conf);//Get File systemif (Hdfs.isdirectory (MyPath)){//If this output path exists in the file system, delete theHdfs.delete (MyPath, true);} Job Wcjob = new Job (conf, "WC");//Build a Job object named TestanagramSet the jar package for the classes that are used by the entire jobWcjob.setjarbyclass (Wcrunner.class);Mapper and reducer classes used by this jobWcjob.setmapperclass (Wcmapper.class);Wcjob.setreducerclass (Wcreducer.class);Specify the output data kv type

();Uri uri = new Uri ("hdfs://hadoopmaster:9000");FileSystem is the core class for user-operated HDFs, which obtains the HDFs file system for the URIFileSystem FileSystem = Filesystem.get (URI, conf);Source file pathPath Srcpath = new path (source);Destination PathPath Dstpath = new Path (dest);See if the destination path existsif (! ( Filesystem.exists (Dstpath))) {If the path does not exist, create it immediatelyFilesystem.mkdirs (Dstpath);}Get local file nameString filename = source.substrin

description and submission classespublic class Flowsumrunner extends configured implements tool{public int run (string[] arg0) throws Exception {Configuration conf = new configuration ();Job Job = job.getinstance (conf);Job.setjarbyclass (Flowsumrunner.class);Job.setmapperclass (Flowsummapper.class);Job.setreducerclass (Flowsumreducer.class);Job.setmapoutputkeyclass (Text.class);Job.setmapoutputvalueclass (Flowbean.class);Job.setoutputkeyclass (Text.class);Job.setoutputvalueclass (Flowbean.clas

= Mypath.getfilesystem (conf);if (Hdfs.isdirectory (MyPath)){Hdfs.delete (MyPath, true);}@SuppressWarnings ("deprecation")Job Job = new Job (conf, "gender");//Create a new taskJob.setjarbyclass (Gender.class);//Main classJob.setmapperclass (pcmapper.class);//mapperJob.setreducerclass (pcreducer.class);//reducerJob.setpartitionerclass (Myhashpartitioner.class);Job.setpartitionerclass (Pcpartitioner.class);//Set Partitioner classJob.setnumreducetasks (3);//reduce number set to 3Job.setmapoutputke

(Firstpartitioner.class);//partition functionJob.setsortcomparatorclass (Keycomparator.class);//This course does not have custom sortcomparator, but instead uses Intpair's own sortJob.setgroupingcomparatorclass (Groupingcomparator.class);//Group functionJob.setmapoutputkeyclass (Intpair.class);Job.setmapoutputvalueclass (Intwritable.class);Job.setoutputkeyclass (Text.class);Job.setoutputvalueclass (Intwritable.class);Job.setinputformatclass (Textinputformat.class);Job.setoutputformatclass (Text

Linux inter-process communication (IPC) Programming Practice (7) use of shared memory-System V shared memory (API) The system call mmap mentioned in the previous blog map a common file to implement shared memory. The System V shared memory described in this article is to map files in the shm of a special file System to implement shared memory communication between processes. That is to say, each shared memo

, Reducebykeyandwindow (_ + , -_, Seconds (5), Seconds (1))See the difference between the two:The first is simple, crude, direct accumulation.And the second way is more elegant and efficient.For example, calculate the cumulative data for t+4 nowThe first way is directly from t+...+ (T+4)The second treatment is that, with the computed (t+3) data Plus (T+4) data, in the minus (t-1) of the data, you can get the same results as the first way, but the intermediate multiplexed three data (t+1,t+2,t+3)

Registry This is a fun thing to do, but it's always a hassle to find what you need in a layer-by-layer containment relationship, and who remembers the path?Anyway, I will not remember, write a small program, let the path saved into the code inside. Release your brain's storage capacity.The individual demonstrates simple programming of the Registry API as an example of an aero effect that opens Windows 8.Pro

DirectX API programming started #01 project settings, I learned how to use the DirectX API from scratch. Tutorial: rastertek-> DirectX 11 TutorialsPreparations 1) first, we need a set of software that can write code. I use Microsoft's own IDE: Visual Studio2015 VS2015 community edition (free) For beginners, a good IDE can indeed improve efficiency. However, it de

structure Pshared: When not 0, the semaphore is shared between processes, otherwise it can only be shared for all threads of the current process Value: The initial value of the semaphore The signal volume minus 1 operation, when sem=0 the function will blockint sem_wait(sem_t *sem); Successful return 0, failure return-1 Parameters SEM: A pointer to the semaphore Signal Volume plus 1 operationint sem_post(sem_t *sem); Parameter

Microsoft has made a lot of interfaces for programming with DirectX brothers. We can see below ildasm that there is only one class named filgraphmanagerclass. In fact, I have read it carefully, there are not many large functions. DirectX is divided into four layers in abstraction, Hardware/network layer: multimedia devices, including Graphics accelerators, sound cards, input devices, and network communication devices; DirectX base layer: provides basi

SendBuf; while (Getline (CIN,SENDBUF)) { if (!clientsocket.send (clientsocket,sendbuf)) { Err_exit (" Send Error "); } Sendbuf.clear (); if (!clientsocket.receive (clientsocket,sendbuf)) { err_exit ("Receive error"); } cout Attached -commen.h#ifndef comment_h_included#define comment_h_included#include "Socket.h" #include Attached -makefileCC = g++ Cppflags =-wall-g-pthreadbin = Server Clientsources = $ (bin.=.cp

I. What is SVG? SVG is a 2D graphic description language released by W3C in 1999. It is a markup language based solely on XML format.The full name is extensible vector graphics, which is very different from traditional Raster graphics (JPG, PNG, GIF, etc.).No. SVG is a 2D graphics development platform. It consists of two parts: XML-based data description andThe other part is a programmable API. Its key features support graphics, text, gradient fill, p

Linux inter-process communication (IPC) programming practices (8) use of shared memory-POSIX shared memory (API) 1. Posix provides two methods to share memory areas between unrelated processes: (1) memory ing file: open the function first, and then call the mmap function to map the obtained descriptor to a file in the current process address space (this is used in the previous blog ). (2) shared memory area