making spearman correlation cor() call fail with log(0) as input

-----Original Message-----
From: Timur Shtatland [mailto:tshtatland at gmail.com]
Sent: Thursday, September 11, 2008 6:03 PM
To: Greg Snow
Cc: r-help at r-project.org
Subject: Re: [R] making spearman correlation cor() call fail
with log(0) as input

You are right, Inf and -Inf are not considered errors in R,
they are accepted as input to Spearman's cor(), and so I will
have to check the input myself for such condition.
Thank you for pointing this out!

Timur

On Wed, Sep 10, 2008 at 8:50 PM, Greg Snow
<Greg.Snow at imail.org> wrote:

Your code shows no errors only correct responses.

If you want an error when R is generating correct results,

you will need to check for the conditions yourself.

-----Original Message-----
From: "Timur Shtatland" <tshtatland at gmail.com>
To: "r-help at r-project.org" <r-help at r-project.org>
Sent: 9/10/08 3:51 PM
Subject: [R] making spearman correlation cor() call fail

with log(0)

as input


Hi,

How can I make the cor(x, y, method="spearman") call to produce an
error when the input to it (x, y) produces an error? Here

is a simple

example:

a <- c(0, 1, 2)
b <- c(100, 2, 4)

## error:

log(a)

[1]      -Inf 0.0000000 0.6931472

## error, as expected:

cor(log(a), log(b), method="pearson")

[1] NaN

## not an error any more (not expected):

cor(log(a), log(b), method="spearman")

[1] -0.5

cor(log(a), log(b), method="spearman", use="all.obs")

[1] -0.5

sessionInfo()

R version 2.6.1 (2007-11-26)
i686-pc-linux-gnu

locale:

LC_CTYPE=en_US;LC_NUMERIC=C;LC_TIME=en_US;LC_COLLATE=en_US;LC_MONETARY

=en_US;LC_MESSAGES=en_US;LC_PAPER=en_US;LC_NAME=C;LC_ADDRESS=C;LC_TELE

PHONE=C;LC_MEASUREMENT=en_US;LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

Thank you for your help.

Best regards,

Timur Shtatland