[R] Failed to install RMySQL,help!

I had installed R and MySQL ,then I input : > install.packages('RMySQL',type='source') show the message below, Why? Why shows "ERROR: configuration failed for package 'RMySQL'"? 试开URL’http://mirrors.xmu.edu.cn/CRAN/src/contrib/RMySQL_0.9-3.tar.gz' Content type 'application/x-gzip' length 165363

[R] I don't know the difference between rank and order

I don't know the difference between rank and order.For example: > x=c(10,30,30,20,10,20) > x[rank(x,ties.method="first")] [1] 10 10 20 30 30 20 > x[order(x)] [1] 10 10 20 20 30 30 the result is quite different, x[rank(x,ties.method="first")] [1] 10 10 20 30 30 20 It is not sorted,why? -- View

Re: [R] read.table

> read.table("data.txt",header=TRUE, colClasses=c("character","character","numeric","character", "numeric","numeric")) a b c d e f 1 SPX LSZ 100 C 0 34.40 2 SPX LSZ 100 P 0 1.30 3 SPX LSZ 105 C 0 30.30 4 SPX LSZ 105 P 0 1.85 5 SPX LSZ 110 C 0 26.40 It's right result! "header=TRUE",no