Reading Data There are a few principal functions reading data into R. read.table, read.csv, for reading tabular data readLines, for reading lines of a text file source, for reading in R code files (inverse of dump) dget, for reading in R code files (…

博客总目录,记录学习R与数据分析的一切:http://www.cnblogs.com/weibaar/p/4507801.html  --- 好久没发博客 且容我大吼一句 终于做完这周R Programming的作业了! 之前一直有报coursera的课程,但是总是没有坚持下去,这次收到他们的邮件推广,说data science系列课程开通了R语言的中文课程,有中文版论坛,有中文字幕,如此诚意满满,再不报名,就实在太落伍了. 为了让自己坚持,还花钱买了signature track,所以当这周五…

完成R Programming第三周 这周作业有点绕,更多地是通过一个缓存逆矩阵的案例,向我们示范[词法作用域 Lexical Scopping]的功效.但是作业里给出的函数有点绕口,花费了我们蛮多心思. Lexical Scopping: The value of free variables are searched for in the environment where the function was defined. 因此 make.power<-function(n){ pow<…

这是原帖 http://www.reddit.com/r/programming/comments/358tnp/five_programming_problems_every_software_engineer/ 后来作者被人发现他自己给的solution是错的,然后有人调侃他自己应该通不过自己的面试. http://www.reddit.com/r/programming/comments/35cr6n/real_programmers_can_do_these_problems_easil…

这个报错网上搜索了一下,大部分是由于MySQL意外关闭或强制重启造成的binlog文件事务点读取异常造成的主从同步报错 Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'binlog truncated in the middle of event; consider out of disk space on master; the last event was read fro…

本地MySQL环境,是两台MySQL做M-M复制.今天发现错误信息: mysql 5.5.28-log> show slave status\G *************************** 1. row ***************************                Slave_IO_State:                   Master_Host: 88.88.88.88                   Master_User: replicate…

mysql> show slave status\G *************************** 1. row ***************************                Slave_IO_State:                    Master_Host: 10.122.41.208                   Master_User: replication                   Master_Port: 3306    …

/*Author: Jiangong SUN*/ As I've manipulated a lot of data using SQL data reader in recent project. And people says it's not good to access the data by column name. So I've made an performance test in reading data from SQL data reader. Firstly, I've…

    R语言data.table包是自带包data.frame的升级版,用于数据框格式数据的处理,最大的特点快.包括两个方面,一方面是写的快,代码简洁,只要一行命令就可以完成诸多任务,另一方面是处理快,内部处理的步骤进行了程序上的优化,使用多线程,甚至很多函数是使用C写的,大大加快数据运行速度.因此,在对大数据处理上,使用data.table无疑具有极高的效率.这里我们主要讲的是它对数据框结构的快捷处理. 和data.frame的高度兼容 DT = data.table(x=rep(c("b&…

Querying or Reading Data OpenTSDB offers a number of means to extract data such as CLI tools, an HTTP API and as a GnuPlot graph. Querying with OpenTSDB's tag based system can be a bit tricky so read through this document and checkout the following p…