From: Uwe Ligges <ligges_at_statistik.uni-dortmund.de>

Date: Tue 25 Oct 2005 - 03:06:59 EST

}

}

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Tue Oct 25 03:18:06 2005

Date: Tue 25 Oct 2005 - 03:06:59 EST

ronggui wrote:

> The green book tells:"The basic technique is classic :keep it simple ."A long ,complicated expression or function is less fravorable than" a relatively small computations that combines calls to a few other functions to perform its tasks."

*>
**> But I don't get the point totally.Can anyone give me an example to make me understand this rules totally?
**>
**> ps:
**> Is it mean that f1 is better than f2? Thank you!
**>
**>
**> f1<-function(x){
**> n<-length(x)
**> s<-sum(x)
**> m<-s/n}
**>
**> f2<-
**> function(x){
**> m<-sum(x)/length(x)}
*

No, it means collecting sensible small parts of the code into separate functions as in

f1 <- function(x, .....){ x1 <- f1a(x, ......) x2 <- f1b(x1, .....) x3 <- f1a(x2, .....) f1c(x1, x2, x3, .....)

}

which is "better" than

f2 <- function(.....){

## ## many lines calculating stuff as in f1a ## ## many lines calculating stuff as in f1b ## ## many lines calculating stuff as in f1a ## ## many lines calculating stuff as in f1c ##

}

Uwe Ligges

*>
**> 2005-10-23
**>
*

> ------

*> Deparment of Sociology
**> Fudan University
**>
**> My new mail addres is ronggui.huang@gmail.com
**> Blog:http://sociology.yculblog.com
**>
**>
**>
**> ------------------------------------------------------------------------
**>
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*

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Tue Oct 25 03:18:06 2005

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