R devel - Jul 2006 - Bug?: summary() fails after use of na.action="na.exclude" in lm()

Hello!

I have encountered a weird problem and I am wondering if this is a bug.
Here is the example:

n <- 50
x <- runif(n=n)
y1 <- 2 * x + rnorm(n=n)
y2 <- 5 * x + rnorm(n=n)
y2[sample(1:n, size=5)] <- NA

y <- cbind(y1, y2)

fit <- lm(y1 ~ 1, na.action="na.exclude")
summary(fit)

## Goes ok here
fit <- lm(y2 ~ 1, na.action="na.exclude")
summary(fit)

## But fails if we use matrix of response variables
fit <- lm(y ~ 1, na.action="na.exclude")
summary(fit)

## Response y1 :
##
## Call:
## lm(formula = y1 ~ 1, na.action = "na.exclude")
##
## Residuals:
## Error in quantile.default(resid) : missing values and NaN's not
allowed if 'na.rm' is FALSE

Am I doing something wrong here?

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Btw. man page of lm says (in the begining of the details):

"A typical model has the form 'response ~ terms' where
'response' is the
(numeric) response vector ..."
                   ^^^^^^

Should not this part say that repsponse can also be a matrix?

Thanks

-- 
Lep pozdrav / With regards,
    Gregor Gorjanc

----------------------------------------------------------------------
University of Ljubljana     PhD student
Biotechnical Faculty
Zootechnical Department     URI: http://www.bfro.uni-lj.si/MR/ggorjan
Groblje 3                   mail: gregor.gorjanc <at> bfro.uni-lj.si

SI-1230 Domzale             tel: +386 (0)1 72 17 861
Slovenia, Europe            fax: +386 (0)1 72 17 888

----------------------------------------------------------------------
"One must learn by doing the thing; for though you think you know it,
 you have no certainty until you try." Sophocles ~ 450 B.C.

On Wed, 19 Jul 2006, Gregor Gorjanc wrote:
> I have encountered a weird problem and I am wondering if this is a bug.
> Here is the example:
>
> n <- 50
> x <- runif(n=n)
> y1 <- 2 * x + rnorm(n=n)
> y2 <- 5 * x + rnorm(n=n)
> y2[sample(1:n, size=5)] <- NA
>
> y <- cbind(y1, y2)
>
> fit <- lm(y1 ~ 1, na.action="na.exclude")
> summary(fit)
>
> ## Goes ok here
> fit <- lm(y2 ~ 1, na.action="na.exclude")
> summary(fit)
>
> ## But fails if we use matrix of response variables
> fit <- lm(y ~ 1, na.action="na.exclude")
> summary(fit)
>
> ## Response y1 :
> ##
> ## Call:
> ## lm(formula = y1 ~ 1, na.action = "na.exclude")
> ##
> ## Residuals:
> ## Error in quantile.default(resid) : missing values and NaN's not
> allowed if 'na.rm' is FALSE
>
Yes, I think it's a bug.

  summary.mlm() produces an object that is a list of objects of class 
"summary.lm", but these objects get their $resid component from the 
residuals() function and so NAs in their $resid component where a 
"summary.lm"  produced by summary.lm() would not.

 	-thomas