Displaying 20 results from an estimated 6900 matches for "weights".
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2000 Jan 04
0
Stepwise logistic discrimination - II
...+351-22-5580043
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> nose20s.mu <- multinom(Spoilage ~ FRAG25 + FRAG26 + FRAG27 + FRAG28 + FRAG29 + FRAG30 + FRAG31 + FRAG32 + FRAG33 + FRAG34 + FRAG35 + FRAG36 + FRAG37 + FRAG38 + FRAG39 + FRAG40 + FRAG41 + FRAG42 + FRAG43 + FRAG44 + FRAG45 , nose126s)
# weights: 92 (66 variable)
> nose20s.mu
Call:
multinom(formula = Spoilage ~ FRAG25 + FRAG26 + FRAG27 + FRAG28 +
FRAG29 + FRAG30 + FRAG31 + FRAG32 + FRAG33 + FRAG34 + FRAG35 +
FRAG36 + FRAG37 + FRAG38 + FRAG39 + FRAG40 + FRAG41 + FRAG42 +
FRAG43 + FRAG44 + FRAG45, data = nose126s)
Coeffic...
2002 Feb 06
4
Weighted median
Is there a weighted median function out there similar to weighted.mean()
but for medians? If not, I'll try implement or port it myself.
The need for a weighted median came from the following optimization
problem:
x* = arg_x min (a|x| + sum_{k=1}^n |x - b_k|)
where
a : is a *positive* real scalar
x : is a real scalar
n : is an integer
b_k: are negative and positive scalars
2011 Jan 17
2
Using summaryBy with weighted data
Dear Soren and R users:
I am trying to use the summaryBy function with weights. Is this possible? An example that illustrates what I am trying to do follows:
library(doBy)
## make up some data
response = rnorm(100)
group = c(rep(1,20), rep(2,20), rep(3,20), rep(4,20), rep(5,20))
weights = runif(100, 0, 1)
mydata = data.frame(response,group,weights)
## run summaryBy wit...
2006 Aug 04
2
why does lm() not allow for negative weights?
Dear List,
Why do commonly used estimator functions (such as lm(), glm(), etc.) not
allow negative case weights? I suspect that there is a good reason for this.
Yet, I can see reasonable cases when one wants to use negative case weights.
Take lm() for example:
###
n <- 20
Y <- rnorm(n)
X <- cbind(rep(1,n),runif(n),rnorm(n))
Weights <- rnorm(n)
# Includes Pos and Neg Weights
Weights
# Now do W...
2007 May 31
3
Problem with Weighted Variance in Hmisc
The function wtd.var(x,w) in Hmisc calculates the weighted variance of x
where w are the weights. It appears to me that wtd.var(x,w) = var(x) if all
of the weights are equal, but this does not appear to be the case. Can
someone point out to me where I am going wrong here? Thanks.
Tom La Bone
[[alternative HTML version deleted]]
2012 Oct 08
1
weighted cumulative distribution with ggplot2
Dear all,
I am trying to draw a weighted cumulative distribution (as defined
here http://rss.acs.unt.edu/Rdoc/library/spatstat/html/ewcdf.html)
with ggplot2
however the syntax
temp<-qplot(X,weight=weight,data=data,stat = "ecdf", geom =
"step",colour=factor(year))
seems not to produce exactly the right figure (the values seems higher
at some points)... I am wrong in the
2009 Nov 14
4
Weighted descriptives by levels of another variables
...stics on groups of variables, including
summary {stats}, describe {Hmisc}, and describe {psych}, but none that
I have found is able to provided weighted descriptives of subsets of a
data set (ex. descriptives for both males and females for age, where
accurate results require use of sampling weights).
Does anybody know of a function that does this?
What I've looked at already:
I have looked at describe.by {psych} which will give descriptives by
levels of another variable (eg. mean ages of males and females), but
does not accept sample weights.
I have also looked at describe {Hmisc}...
2012 Jul 03
2
EM algorithm to find MLE of coeff in mixed effects model
...row is the miu_i
tmp1=permutations(length(gausspar$nodes),2,repeats.allowed=T)
tmp2=c(tmp1)
a.mat=matrix(gausspar$nodes[tmp2],nrow=nrow(tmp1)) #a1,a1
#a1,a2
#...
#a10,a9
#a10,a10
a.mat.list=as.list(data.frame(t(a.mat)))
tmp1=permutations(length(gausspar$weights),2,repeats.allowed=T)
tmp2=c(tmp1)
weights.mat=matrix(gausspar$weights[tmp2],nrow=nrow(tmp1)) #w1,w1
#w1,w2
#...
#w10,w9
#w10,w10
L=chol(solve(W.hat))
LL=sqrt(2)*solve(L)
halfb=t(LL%*%t(a.mat))
# each page of b.array is all values of bi_k and bi_j for b_...
2008 Mar 10
3
Weighting data when running regressions
...le where WEIGHT is the name of my
weighting variable (numeric), e.g.:
library(foreign)
data1=read.spss("File.sav", use.value.labels = FALSE, to.data.frame = TRUE)
summary(data1) ' shows me all the variables OK
attach(data1)
linmod=lm(Y~X1+X2+X3+X4W, subset=(X5==1 & X6==7), weights==WEIGHT)
and I get the following Error message:
Error in weights == WEIGHT :
comparison (1) is possible only for atomic and list types
It works perfectly if I don't use the ", weights==WEIGHT" bit
Could you please let me know what I am doing wrong?
Thank yo...
2006 Aug 30
5
working with summarized data
...--e.g.,
each row doesn't mean 1 observation.
With that in mind, nearly all of the graphs and summary statistics
are incorrect for my data, because they don't take into account the
weight.
****
For example "median" is incorrect, as the quantiles aren't calculated
with weights:
sum( weights[X < median(X)] ) / sum(weights)
This should be 0.5... of course it's not.
****
Unfortunately, it seems that most(all?) of R's graphics and summary
statistic functions don't take a weight or frequency argument.
(Fortunately the models do...)
Am I completely mis...
2008 Jul 23
2
Weighted variance function?
There is a R function to calculate weighted mean : weighted.mean() under
stats package. Is there any direct R function for calculating weighted
variance as well?
[[alternative HTML version deleted]]
2005 Apr 13
1
logistic regression weights problem
Hi All,
I have a problem with weighted logistic regression. I have a number of
SNPs and a case/control scenario, but not all genotypes are as
"guaranteed" as others, so I am using weights to downsample the
importance of individuals whose genotype has been heavily "inferred".
My data is quite big, but with a dummy example:
> status <- c(1,1,1,0,0)
> SNPs <- matrix( c(1,0,1,0,0,0,0,1,0,1,0,1,0,1,1), ncol =3)
> weight <- c(0.2, 0.1, 1, 0.8, 0.7)
> glm(s...
2011 Jul 06
2
how to best present concentrated data points/ ggplot2
...types and want to show the data points on the x axis.
The code is as follows. The data points are very concentrated. Is there a better way to present it( should I set the alpha value or something else)?
Thanks!
YL
library(ggplot2)
x <- rnorm(10000)
a <- rnorm(5000)
b <- rnorm(5000)
weights.x <- abs(a/sum(a))
weights.y <- abs(b/sum(b))
weight <- c(weights.x, weights.y)
ze <- rep(0,10000)
type <- c(rep("a",5000), rep("b",5000))
d <- data.frame(expo = x, weight = weight, type = type, ze = ze)
m <- ggplot(d, aes(x = expo, group = type, col =...
2017 May 11
2
What's the weight means in the dump of edge info from USR2?
Thank you, that is very helpful. And actually I do have a few further questions regarding this:
1. This weight is not the one specified in Subnet, this should be something related to the host, where can I manually configure this?
2. The weight value is ONLY take round trip latency as the measurement, or including CPU power and other factors into consideration?
3. I don't know how this
2012 Jul 18
1
How does "rlm" in R decide its "w" weights for each IRLS iteration?
Hi all,
I am also confused about the manual:
a. The input arguments:
wt.method are the weights case weights (giving the relative importance of
case, so a weight of 2 means there are two of these) or the inverse of the
variances, so a weight of two means this error is half as variable?
w (optional) initial down-weighting for each case.
init (optional) initial values for the coefficients OR...
2009 Jul 23
5
Random # generator accuracy
...d "random" result."
I've re-created what I did below. The problem appears to be with the
weighting process: the unweighted sample came out much closer to the actual
than the weighted sample (>1% error) did. Comments?
Jim
> x
[1] 1 2 3 4 5 6 7 8 9 10 11 12
> weights
[1] 1 1 1 1 1 1 2 2 2 2 2 2
> a = mean(replicate(1000000,(sample(x, 3, prob = weights))));a # (1
million samples from x, of size 3, weighted by "weights"; the mean should
be 7.50)
[1] 7.406977
> 7.406977/7.5
[1] 0.987597
> b = mean(replicate(1000000,(sample(x, 3))));b # (1 m...
2008 Jun 03
3
Rpart and case weights: working with functions
I can't get rpart accept case weights defined inside a function.
It keeps using the copy defined in the "global" environment (if they
exists) instead of the function-defined ones.
Here is what I do:
test.function <- function (formula, data) {
weights <- rep(.1, 100)
rpart(formula, data, weights)
}
test.functio...
2007 May 08
5
Weighted least squares
...'m struggling with weighted least squares, where something that I had
assumed to be true appears not to be the case. Take the following
data set as an example:
df <- data.frame(x = runif(100, 0, 100))
df$y <- df$x + 1 + rnorm(100, sd=15)
I had expected that:
summary(lm(y ~ x, data=df, weights=rep(2, 100)))
summary(lm(y ~ x, data=rbind(df,df)))
would be equivalent, but they are not. I suspect the difference is
how the degrees of freedom is calculated - I had expected it to be
sum(weights), but seems to be sum(weights > 0). This seems
unintuitive to me:
summary(lm(y ~ x, data=df, w...
2017 May 10
2
What's the weight means in the dump of edge info from USR2?
Hi, tinc experts
abc to def at x.x.x.x port 655 options d weight 540
How’s the 540 weight been calculated? What does it mean? How can I leverage this weight?
The d of after options mean direct?
2010 Apr 16
2
Weights in binomial glm
I have some questions about the use of weights in binomial glm as I am
not getting the results I would expect. In my case the weights I have
can be seen as 'replicate weights'; one respondent i in my dataset
corresponds to w[i] persons in the population. From the documentation
of the glm method, I understand that the weights can indeed...