R help - Oct 2007 - correlated data

Hi!!

I am trying to generate data with specific correlation using corgen method from
the ecodist package. It does not seem to generate the data properly. I am
listing the code below. Secondly, when I put the code given below all in one
file and source it, it is unable to complete the task. But when I execute it one
at a time it is able to complete it. Can someone point out any mistake that I
may be making?
Thanks ../Murli


library(ecodist)
x<-1:100
y<-corgen(x=x, r=.8, epsilon=0.01, population=FALSE)$y
colnames(data)<-c("x", "y")
write.csv(data, file="artDataCorrPt8.csv")
rm(data)

y<-corgen(x=x, r=.3, epsilon=0.01, population=FALSE)$y
colnames(data)<-c("x", "y")
write.csv(data, file="artDataCorrPt3.csv")
rm(data)

y<-corgen(x=x, r=0, epsilon=0.01, population=FALSE)$y
colnames(data)<-c("x", "y")
write.csv(data, file="artDataCorr0.csv")
rm(data)

y<-corgen(x=x, r=-0.8, epsilon=0.01, population=FALSE)$y
colnames(data)<-c("x", "y")
write.csv(data, file="artDataCorrMinusPt8.csv")
rm(data)


y<-corgen(x=x, r=1, epsilon=0.01, population=FALSE)$y
colnames(data)<-c("x", "y")
write.csv(data, file="artDataCorr1.csv")
rm(data)

y<-corgen(x=x, r=-0.9, epsilon=0.01, population=FALSE)$y
colnames(data)<-c("x", "y")
write.csv(data, file="artDataCorrMinusPt9.csv")
rm(data)



	[[alternative HTML version deleted]]

Hi,

What's "properly"? What are you trying to do - you don't
ever say.

I think you need to set population=TRUE to get the result you
appear to want (sorry, that's not entirely clear in the docs, I see).
> x <- 1:100
> y <- corgen(x=x, r=.8, epsilon=.01, population=TRUE)$y
> cor(x, y)
          [,1]
[1,] 0.8091115


But there seem to be some more problems in your code:
>
> library(ecodist)
> x<-1:100
> y<-corgen(x=x, r=.8, epsilon=0.01, population=FALSE)$y
> colnames(data)<-c("x", "y")
> write.csv(data, file="artDataCorrPt8.csv")
> rm(data)
What's data? Where does it come from? If you want to
save your results, you need an extra line:
data <- cbind(x, y)

Since you never specify what data is, you will get errors,
the wrong output files, and it won't run as a script.

If you have problems with ecodist, you can always contact
me directly - I'm listed as package maintainer.

Sarah

-- 
Sarah Goslee
http://www.functionaldiversity.org