yea, I have read the help. But some one tell me that i f you want use a vector that you don't know it's length, you should use xx=numric(0) , is it not right? If it isn't right, how can I do? thanks
-----Original Message----- From: Douglas Grove [mailto:[EMAIL PROTECTED] Sent: Wednesday, June 01, 2005 6:27 AM To: luan_sheng Subject: Re: [R] FW: why is it numeric(0)? Have you read the help page for numeric (?numeric) to understand what it does? You should really look at help pages prior to posting. numeric(x) returns a numeric vector of length x, with all entries initialized to zero so numeric(1) returns 0, numeric(2) returns c(0,0) etc. numeric(0) returns a numeric vector of *length 0*, so when you add anything to it you get the same result (it's basically a numeric NULL) On Wed, 1 Jun 2005, luan_sheng wrote: > hello,everyone. I have one question: > > example 1 > > x=numeric(0) > > y=5 > > print(x+y) > numeric(0) > > example 2 > > x=numeric(1) > > y=5 > > print(x+y) > [1] 5 > > why the print(x+y) is numeric(0) at the first example, but the result > is 0 at the second example? > > > __________________________________________________ > > 雅虎免费G邮箱－中国第一绝无垃圾邮件骚扰超大邮箱 > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > __________________________________________________ 雅虎免费G邮箱－中国第一绝无垃圾邮件骚扰超大邮箱 ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
