Displaying 20 results from an estimated 700 matches similar to: "IWSM 2013: LAST call for papers"
2013 Jan 18
0
OT: IWSM 2013
dear all,
apologizes for this off topic.
I would like to inform you that registration and paper submission for
the 28th International Workshop on Statistical Modelling (IWSM)
to be held in Palermo (Italy) 8-12 July 2013 is now open at
http://iwsm2013.unipa.it
Register at http://iwsm2013.unipa.it/?cmd=registration and then submit
your abstract. Deadlines for Abstract submission is February 4,
2010 Mar 04
1
only actual variable names in all.names()
dear all,
When I use all.vars(), I am interest in extracting only the variable names..
Here a simple example
all.vars(as.formula(y~poly(x,k)+z))
returns
[1] "y" "x" "k" "z"
and I would like to obtain
"y" "x" "z"
Where is the trick?
many thanks
vito
--
====================================
Vito M.R. Muggeo
Dip.to Sc
2009 Nov 02
3
partial matching with grep()
dear all,
This is a probably a silly question.
If I type
> grep("x",c("a.x" ,"b.x","a.xx"),value=TRUE)
[1] "a.x" "b.x" "a.xx"
Instead, I would like to obtain only
"a.x" "b.x"
How is it possible to get this result with grep()?
many thanks for your attention,
best,
vito
--
2010 Oct 25
1
building lme call via call()
dear all,
I would like to get the lme call without fitting the relevant model.
library(nlme)
data(Orthodont)
fm1 <- lme(distance ~ age, random=list(Subject=~age),data = Orthodont)
To get fm1$call without fitting the model I use call():
my.cc<-call("lme.formula", fixed= distance ~ age, random = list(Subject
= ~age))
However the two calls are not the same (apart from the data
2008 May 02
1
error in using by + median
dear all,
Could anyone explain me the behaviour of median() within by()?
(I am running R.2.7.0)
thanks,
vito
> H<-cbind(rep(0:1,l=20),matrix(rnorm(20*2),20,2))
> by(H[,-1],H[,1],mean)
INDICES: 0
V1 V2
-0.2101069 0.2954377
---------------------------------------------------------------------------------------------------------------------
INDICES: 1
V1
2024 May 16
0
segmented 2.1-0 is released
dear R users,
I am pleased to announce that segmented 2.1-0 is now available on CRAN.
segmented focuses on estimation of breakpoints/changepoints of
segmented, i.e. piecewise linear, relationships in (generalized) linear
models. Starting with version 2.0-0, it is also possible to model
stepmented, i.e. piecewise constant, effects.
In the last release both models may be fitted via a formula
2024 May 16
0
segmented 2.1-0 is released
dear R users,
I am pleased to announce that segmented 2.1-0 is now available on CRAN.
segmented focuses on estimation of breakpoints/changepoints of
segmented, i.e. piecewise linear, relationships in (generalized) linear
models. Starting with version 2.0-0, it is also possible to model
stepmented, i.e. piecewise constant, effects.
In the last release both models may be fitted via a formula
2012 Jun 01
1
getting the name of the working .Rdata file
dear all,
I do not if it is a nonsense question..
Is it possible in the R session to get the name of the current .Rdata
file that I ran?
I mean: suppose I double click the file myfile.Rdata. ls() returns the
names of the objects in the current workspace (that is saved in
myfile.Rdata). In the current R session, I would like to obtain
"myfile.Rdata". Is it possible?
Thanks in
2012 Mar 21
1
glmnet() vs. lars()
dear all,
It appears that glmnet(), when "selecting" the covariates entering the
model, skips from K covariates, say, to K+2 or K+3. Thus 2 or 3
variables are "added" at the same time and it is not possible to obtain
a ranking of the covariates according to their importance in the model.
On the other hand lars() "adds" the covariates one at a time.
My question
2018 Jan 30
2
variable names in lm formula ~.
dear all,
Is the following intentional? Am I missing anything in documentation?
d<-data.frame(y=rnorm(10,5,.5),exp=rnorm(10), age=rnorm(10))
formula(lm(exp(y)~exp+age, data=d))
#--> exp(y) ~ exp + age
formula(lm(exp(y)~., data=d))
#--> exp(y) ~ age
variable 'exp' (maybe indicating "experience") is not included in the
model. The same happens with 'log' (and
2005 Mar 11
0
Negative binomial regression for count data,
Dear list,
I would like to know:
1. After I have used the R code (http://pscl.stanford.edu/zeroinfl.r) to fit a zero-inflated negative binomial model, what criteria I should follow to compare and select the best model (models with different predictors)?
2. How can I compare the model I get from question 1 (zero-inflated negative binomial) to other models like glm family models or a logistic
2008 Dec 17
0
OFF topic testing for positive coeffs
Dear all,
This is off-topic,
however I hope someone can give me useful suggestion..
Given the regression model
y = b0 + b1*x + e
I am interested in testing for positive coeffs, namely
H0: b0>0 AND b1>0
H1: b0,b1 unconstrained
It is simple to estimate the model under H0 and H1 (there are several
suggestions on the Rlist about estimation but nothing about testing..)
perform a likelihood
2008 Jun 30
2
difference between MASS::polr() and Design::lrm()
Dear all,
It appears that MASS::polr() and Design::lrm() return the same point
estimates but different st.errs when fitting proportional odds models,
grade<-c(4,4,2,4,3,2,3,1,3,3,2,2,3,3,2,4,2,4,5,2,1,4,1,2,5,3,4,2,2,1)
score<-c(525,533,545,582,581,576,572,609,559,543,576,525,574,582,574,471,595,
557,557,584,599,517,649,584,463,591,488,563,553,549)
library(MASS)
library(Design)
2018 May 21
2
removing part of a string
dear all,
I am stuck on the following problem. Give a string like
ss1<- "z:f(5, a=3, b=4, c='1:4', d=2)"
or
ss2<- "f(5, a=3, b=4, c=\"1:4\", d=2)*z"
I would like to remove all entries within parentheses.. Namely, I aim to
obtain respectively
"z:f()" or "f()*z"
I played with sub() and gsub() but without success..
Thank you very
2004 Dec 14
1
correlation in lme4
Dear all,
I have tried to consider a correlation structure in lme (package lme4), but
without success.
I have used something like:
> risul<-lme(y~x+ z , data=mydata, random=~ x | g, correlation = corAR1())
but the result is the same as:
> risul<-lme(y~x+ z , data=mydata, random=~ x | g).
Can anybody help me?
Antonella
**************************************************
Prof.
2024 Jul 26
1
Automatic Knot selection in Piecewise linear splines
dear all,
I apologize for my delay in replying you. Here my contribution, maybe
just for completeness:
Similar to "earth", "segmented" also fits piecewise linear relationships
with the number of breakpoints being selected by the AIC or BIC
(recommended).
#code (example and code from Martin Maechler previous email)
library(segmented)
o<-selgmented(y, ~x, Kmax=20,
2005 May 05
2
names(dist(mat)) gives NULL in R 2.1.0
Dear list,
I do not know if this is a bug.
Let's suppose mat is a matrix derived from this code:
> x<-rnorm(10)
> y<-rnorm(10)
> names(x)<-LETTERS[1:10]
> names(y)<-LETTERS[1:10]
> mat<-cbind(x,y)
Now in R 2.0.1 I have:
> names(dist(mat))
"A" "B" "C" "D" "E" "F" "G" "H"
2011 Jan 14
2
selecting elements in vector
Hi everybody,
I have the following problem. I have a vector containing character elements,
such as:
list = c("aa","bb","cc","dd","ee")
I want to create an index which identifies the elements that are different
from, e.g. "aa" and "bb".
When I do the following:
jj = list!="aa" & list!="bb"
> jj
2004 May 11
2
bilinear and non linear
Dear all,
there are R packages able to simulate or estimate bilinear model for time
series?
I know it is an open problem, but do exist something for very simplified
bilinear models?
Alternatively, what kinfd of non linear time series models are performed
in R?
If R is not able, could someone suggest me for some commercial softwares
to deal with bilinear models?
i'm afraid of a negative
2008 Oct 27
3
counting run lengths
Hello,
I have the following problem.
I am running simulations on possible states of a set of agents
(1=employed, 0=unemployed).
I store these simulated time series in a matrix like the following,
where rows indicates time periods, columns the number of agents (4
agents and 8 periods in this case):
Atr=[
1 1 1 1
1 1 0 1
1 1 0 1
1 1 0 1
0 1 0 1
0