On Wed, 26 Sep 2007, Gabor Grothendieck wrote:
I thought that perhaps the behavior in the previous post,
while inconsistent with the documentation, was not all that
harmful but I think its related to the following which is a potentially
serious bug.
The previous discussion already
Thanks for the explanation.
For lists either: (a) promises should be evaluated as they
enter the list or (b) promises evaluated as they exit the
list (i.e. as they are compared, inspected, etc.). I gather
the intent was (a) but it does not happen that way due to
a bug in R. Originally I
Joe,
which version of R and RJDBC are you using? The behavior you describe
should have been fixed in RJDBC 0.1-4. Please try the latest version
from rforge
install.packages(RJDBC,,http://rforge.net/;)
and please let me know if that solves your problem.
Cheers,
Simon
On Sep 26, 2007, at
On Wed, Sep 26, 2007 at 10:52:28AM -0700, Byron Ellis wrote:
For the most part, doing anything to an R object result in it's
duplication. You generally have to do a lot of work to NOT copy an R
object.
Thank you for your response. Unfortunately, you are right. For example,
the allocated memory
In my previous email, I sent the example:
a - matrix(as.integer(1),nrow=14100,ncol=14100) # 774m
a[1,1] - 0 # 3.0g
gc() # 1.5g
This is misleading. The correct version is
a - matrix(as.integer(1),nrow=14100,ncol=14100) # 774m
a[1,1] - as.integer(0) # 1.5g
gc() # 774m
So, the
On Thu, 27 Sep 2007, Gabor Grothendieck wrote:
Thanks for the explanation.
For lists either: (a) promises should be evaluated as they
enter the list or (b) promises evaluated as they exit the
list (i.e. as they are compared, inspected, etc.).
What makes you conclude that this is what should
Simon Urbanek simon.urbanek at r-project.org writes:
Joe,
which version of R and RJDBC are you using? The behavior you describe
should have been fixed in RJDBC 0.1-4. Please try the latest version
from rforge
install.packages(RJDBC,,http://rforge.net/;)
and please let me know if
Petr Savicky wrote:
On Wed, Sep 26, 2007 at 10:52:28AM -0700, Byron Ellis wrote:
For the most part, doing anything to an R object result in it's
duplication. You generally have to do a lot of work to NOT copy an R
object.
Thank you for your response. Unfortunately, you are right.
1) You implicitly coerced 'a' to be numeric and thereby (almost) doubled
its size: did you intend to? Does that explain your confusion?
2) I expected NAMED on 'a' to be incremented by nrow(a): here is my
understanding.
When you called nrow(a) you created another reference to 'a' in the
Hi all,
A suggestion derived from discussions amongst a number of R users in
my research group: set the default column names produced by aggregate
() equal to the names of the objects in the list passed to the 'by'
object.
ex. it is annoying to type
with(
my.data
You can do this:
aggregate(iris[-5], iris[5], mean)
On 9/27/07, Mike Lawrence [EMAIL PROTECTED] wrote:
Hi all,
A suggestion derived from discussions amongst a number of R users in
my research group: set the default column names produced by aggregate
() equal to the names of the objects in
Understood, but my point is that the naming I suggest should be the
default. One should not be 'punished' for being explicit in calling
aggregate.
On 27-Sep-07, at 1:06 PM, Gabor Grothendieck wrote:
You can do this:
aggregate(iris[-5], iris[5], mean)
On 9/27/07, Mike Lawrence [EMAIL
You can do this too:
aggregate(iris[-5], iris[Species], mean)
or this:
with(iris, aggregate(iris[-5], data.frame(Species), mean))
or this:
attach(iris)
aggregate(iris[-5], data.frame(Species), mean)
The point is that you already don't have to write x = x. The only
reason you are writing it
As others already mentioned, in your example you are first creating an
integer matrix and the coercing it to a double matrix by assigning
(double) 1 to element [1,1]. However, even when correcting for this
mistake, there is an extra copy created when using matrix().
Try this in a fresh vanilla R
Thank you very much for all the explanations. In particular for pointing
out that nrow is not a .Primitive unlike dim, which is the
reason for the difference in their behavior. (I rised the question
of possible bug due to this difference, not just being unsatisfied
with nrow). Also, thanks for:
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