Displaying 20 results from an estimated 4000 matches similar to: "Discourage the weights= option of lm with summarized data"
2017 Oct 09
2
Discourage the weights= option of lm with summarized data
Yes. Thank you; I should have quoted it.
I suggest to remove this text or to add the word "not" at the beginning.
Arie
On Sun, Oct 8, 2017 at 4:38 PM, Viechtbauer Wolfgang (SP)
<wolfgang.viechtbauer at maastrichtuniversity.nl> wrote:
> Ah, I think you are referring to this part from ?lm:
>
> "(including the case that there are w_i observations equal to y_i and
2017 Oct 08
2
Discourage the weights= option of lm with summarized data
Indeed: Using 'weights' is not meant to indicate that the same
observation is repeated 'n' times. As I showed, this gives erroneous
results. Hence I suggested that it is discouraged rather than
encouraged in the Details section of lm in the Reference manual.
Arie
---Original Message-----
On Sat, 7 Oct 2017, wolfgang.viechtbauer at maastrichtuniversity.nl wrote:
Using
2017 Oct 12
4
Discourage the weights= option of lm with summarized data
OK. We have now three suggestions to repair the text:
- remove the text
- add "not" at the beginning of the text
- add at the end of the text a warning; something like:
"Note that in this case the standard estimates of the parameters are
in general not correct, and hence also the t values and the p value.
Also the number of degrees of freedom is not correct. (The parameter
2017 Dec 03
1
Discourage the weights= option of lm with summarized data
Peter,
This is a highly structured text. Just for the discussion, I separate
the building blocks, where (D) and (E) and (F) are new:
BEGIN OF TEXT --------------------
(A)
Non-?NULL? ?weights? can be used to indicate that different
observations have different variances (with the values in ?weights?
being inversely proportional to the variances);
(B)
or equivalently, when the elements of
2017 Oct 09
0
Discourage the weights= option of lm with summarized data
AFAIR, it is a little more subtle than that.
If you have replication weights, then the estimates are right, it is "just" that the SE from summary.lm() are wrong. Somehow, the text should reflect this.
It is of some importance when you put glm() into the mix, because you can in fact get correct results from things like
y <- c(0,1)
w <- c(49,51)
glm(y~1, weights=w,
2017 Nov 28
0
Discourage the weights= option of lm with summarized data
My local R-devel version now has (in ?lm)
Non-?NULL? ?weights? can be used to indicate that different
observations have different variances (with the values in
?weights? being inversely proportional to the variances); or
equivalently, when the elements of ?weights? are positive integers
w_i, that each response y_i is the mean of w_i unit-weight
observations
2017 Nov 28
0
Discourage the weights= option of lm with summarized data
Since the three posters agree (only) that there is a bug, I propose to
file it as a bug, which is the least we can do now.
There is more to it: the only other case of a change in the Reference
Manual which I know of, is also about the weights option! This is in
coxph. The Reference Manual version 3.0.0 (2013) says about coxph:
" ... If weights is a vector of integers, then the estimated
2017 Oct 08
0
Discourage the weights= option of lm with summarized data
Ah, I think you are referring to this part from ?lm:
"(including the case that there are w_i observations equal to y_i and the data have been summarized)"
I see; indeed, I don't think this is what 'weights' should be used for (the other part before that is correct). Sorry, I misunderstood the point you were trying to make.
Best,
Wolfgang
-----Original Message-----
From:
2010 Jul 29
1
[PATCH] Reflow logic to make it easier to follow
The control flow was:
if (!y) {
ppix = ...
}
if (y) {
...
} else if (x) {
use ppix for something
} else {
use ppix for something
}
Merge the if(!y) block with the two else branches. This avoids
a false-positive in the clang static analyzer, it can't know that
!y and x are mutually exclusive.
The result looks something like this:
if (y) {
...
} else {
ppix = ...
if (x) {
2011 Nov 22
5
x, y for point of intersection
Hi everyone,
?
I am trying to get a point of intersection between a
polyline and a straight line ?.. and get the x and y coordinates of this point.
For exemplification consider this:
?
?
set.seed(123)
?
k1 <-rnorm(100, mean=1.77, sd=3.33)
?k1 <- sort(k1)
q1 <- rnorm(100, mean=2.37, sd=0.74)
q1 <- sort(q1, decreasing = TRUE)
plot(k1, q1, xlim <- c((min(k1)-5),
2005 Jul 05
1
Kind of 2 dim histogram - levelplot
Dear R-List,
I've written some code to put measurement values at a position x and y
in bins (xb and yb). It works, but I wonder if there isn't a function
that would do what I do by hand in "# fill data in bins"?
Here is the code:
# data
x <- c( 1.1, 1.5, 2.3, 2.5, 2.6, 2.9, 3.3, 3.5 )
y <- c( 6.3, 6.2, 5.9, 5.3, 5.4, 4.2, 4.8, 4.6 )
val <- c( 50, 58, 32, 14, 12,
2009 Aug 23
2
difficult "for"
Hi,
My english isn't brilliant and my problem is very difficult to describe but
I try ;)
My first question is: May I write loop "for" like this or similar - for (i
in sth : sth[length(sth)], k in sth_else : length(sth_else) ) - I'd like
to have two independent conditions in the same loop "for".
My secound question depend on program below. I'd like to write every
2012 Sep 27
1
Package ‘orcutt’ bug?
Hello~
Did any one have used the package 'orcutt' ?
I find that it can not work smoothly in a single variable regression. I use the example following, it function very well.
But when I regress "cons" on "price" (use the "reg1<-lm(cons~price+income+temp)") , then use "reg11<-cochrane.orcutt(reg1)
". There is an error message “Error in
2013 Feb 20
1
GC encountered a node (…) with an unknown SEXP type
Dear All,
I'm trying to track down a very erratic bug in some fortran; I have an example that
quite consistently segfaults on windoz, and more sporadically on mac, all in the
course of doing some bootstrap calculations, varying the set.seed call, but I'm now
trying to see what is going on on our redhat system:
R version 2.15.1 (2012-06-22) -- "Roasted Marshmallows"
2010 Jul 27
0
3d topographic map [SEC=UNCLASSIFIED]
Hi Sherri,
There are examples of topographic maps which you have been pointed to, however, I suspect that you want to know where you can obtain topographic data from rather than a canned example.
There are quite a few intricacies to the process so I will go through them for you.
(1)
Topography files can be found in the geomapdata library. You will probably want to use the maps package too (if
2011 Apr 07
0
classification
Dear all, this is not a pure R question, but really about how to set up a
multinomial logistic regression model to do a multi-class classification. I
would really appreciate if any of you would give me some of your thoughts and
recommendation.
Let's say we have 3-class classification problem: A, B and C. I have certain
number of samples, with each sample, I have 3 variables (Xa, Xb and
2017 May 31
2
stats::line() does not produce correct Tukey line when n mod 6 is 2 or 3
Le 31/05/2017 ? 17:30, Serguei Sokol a ?crit :
>
> More thorough reading revealed that I have overlooked this phrase in the
> line's doc: "left and right /thirds/ of the data" (emphasis is mine).
Oops. I have read the first ref returned by google and it happened to be
tibco's doc, not the R's one. The layout is very similar hence my mistake.
The latter does not
2006 Jan 04
2
Using 'polygon' in a 3d plot
I'm new to R, after many years of using Matlab. I've found the R
function 'polygon' to be nearly equivalent to the Matlab function
'patch'. For example, the R commands:
plot(c(0, 5), c(0, 4), type = 'n', asp = 1, ann = FALSE)
x <- c(1, 2, 2, 1.5, 1)
z <- c(1, 1, 2, 1.7, 2)
polygon(x, z, col = 'green')
produce a plot with a small green shape exactly
2007 Apr 18
1
Conditional power, predictive power
is there no package/function in R to calculate the conditional power or the
bayesian predictive power for trials with binary endpoints? Thanks
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2017 May 31
4
stats::line() does not produce correct Tukey line when n mod 6 is 2 or 3
Seriously, if a method gives a wrong result, it's wrong. line() does NOT
implement the algorithm of Tukey, even not after the patch. We're not
discussing Excel here, are we?
The method of Tukey is rather clear, and it is NOT using the default
quantile definition from the quantile function. Actually, it doesn't even
use quantiles to define the groups. It just says that the groups