R help - Aug 2012 - Help on calculating spearman rank correlation for a data frame with conditions

Dear all,

Suppose my data frame is as follows:

id  price  distance
1   2     4
1   3    5
...
2  4   8
2  5   9
...
n  3   7
n   8  9

I would like to calculate the rank-order correlation between price and
distance for each id.

cor(price,distance,method = "spearman") calculate a correlation for
all.

Then I tried to use
apply(data,list='id',cor(price , distance , method =
"spearman"))
to

	[[alternative HTML version deleted]]

On Tue, Aug 28, 2012 at 9:01 PM, Yi <liuyi.feier at gmail.com>
wrote:
> Dear all,
>
> Suppose my data frame is as follows:
>
> id  price  distance
> 1   2     4
> 1   3    5
> ...
> 2  4   8
> 2  5   9
> ...
> n  3   7
> n   8  9
>
> I would like to calculate the rank-order correlation between price and
> distance for each id.
>
> cor(price,distance,method = "spearman") calculate a correlation
for all.
>
> Then I tried to use
> apply(data,list='id',cor(price , distance , method =
"spearman"))
> to
>
You seem to have been cut off mid-thought,  but I'm guessing you want
something more like:

tapply(data, data$id, function(x), cor(x$price, x$distance, method
"spearman"))

Cheers,
Michael
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

Hi,
Try this:
dat1<-read.table(text="
id? price? distance
1? 2??? 4
1? 3??? 5
2? 4? 8
2? 5? 9
3? 6? 3
3? 4? 8 
",sep="",header=TRUE)
dat2<-split(dat1,dat1$id)
?lapply(dat2,function(x) cor(x[2],x[3],method="spearman"))
A.K.




----- Original Message -----
From: Yi <liuyi.feier at gmail.com>
To: R-help at r-project.org
Cc: 
Sent: Tuesday, August 28, 2012 10:01 PM
Subject: [R] Help on calculating spearman rank correlation for a data frame with
conditions

Dear all,

Suppose my data frame is as follows:

id? price? distance
1?  2? ?  4
1?  3? ? 5
...
2? 4?  8
2? 5?  9
...
n? 3?  7
n?  8? 9

I would like to calculate the rank-order correlation between price and
distance for each id.

cor(price,distance,method = "spearman") calculate a correlation for
all.

Then I tried to use
apply(data,list='id',cor(price , distance , method =
"spearman"))
to

??? [[alternative HTML version deleted]]

______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

> id  price  distance
> 1   2     4
> 1   3    5
> ...
> 2  4   8
> 2  5   9
> I would like to calculate the rank-order correlation between 
> price and distance for each id.
> 
> cor(price,distance,method = "spearman") calculate a 
> correlation for all.
> 
Try by()

#Example
d <- data.frame(g=gl(5, 10), x=rnorm(50), y=rnorm(50))
by(d[,2:3], d$g, cor, method="spearman")
 

*******************************************************************
This email and any attachments are confidential. Any use...{{dropped:8}}