From: Adaikalavan Ramasamy <ramasamy_at_cancer.org.uk>

Date: Wed 27 Jul 2005 - 19:19:00 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 Wed Jul 27 19:21:57 2005

Date: Wed 27 Jul 2005 - 19:19:00 EST

The simplest way would be to ignore them in the sum

sum( ( x - y )/x, na.rm=T )

and notice that I have utilised the vectorised operation. But if you want to, you can explicitly remove them with

good <- which( x != 0 ) sum( ( x[good] - y[good] )/ x[good] )

Regards, Adai

On Wed, 2005-07-27 at 16:51 +0800, Chun-Ying Lee wrote:

> Dear R users:

*>
**> I have two set of data, as follow:
**> x<-c(0,0,0.28,0.55,1.2,2,1.95,1.85,
**> 1.6,0.86,0.78,0.6,0.21,0.18)
**> y<-c(0,0,0,0.53,1.34,1.79,2.07,1.88,
**> 1.52,0.92,0.71,0.55,0.32,0.19)
**> i<-1:length(x)
**>
**> I want to sum each (x[i]-y[i])^2/x[i] together,
**> like:
**> >Sum <-sum((x[i]-y[i])^2/x[i])
**> >Sum
**> [1] NaN
**>
**> Because the denominator shoud not be zero.
**> So I want to overlook those when x[i]=0,
**> and just to sum those x[i] not equal to 0.
**> What should I do?
**> Any suggestion.
**> Thanks in advance !!
**>
**> ______________________________________________
**> 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
*

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 Wed Jul 27 19:21:57 2005

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