Displaying 20 results from an estimated 200 matches similar to: "Newbie on functions"
2007 May 24
3
Problem with numerical integration and optimization with BFGS
Hi R users,
I have a couple of questions about some problems that I am facing with
regard to numerical integration and optimization of likelihood
functions. Let me provide a little background information: I am trying
to do maximum likelihood estimation of an econometric model that I have
developed recently. I estimate the parameters of the model using the
monthly US unemployment rate series
2013 Mar 22
1
Trouble embedding functions (e.g., deltaMethod) in other functions
Dear R community,
I've been writing simple functions for the past year and half and have come
across a similar problem several times. The execution of a function within
my own function produces NaN's or fails to execute as intended. My conundrum
is that I can execute the function outside of my function without error, so
it's difficult for me, as a novice functioneer, to figure out
2004 Feb 17
2
Lattice graphics and strip function
I am looking for examples of code that demonstrates the fine tuning of
the strip panels in lattice graphics and uses plotmath characters. The
code for the graphic is as follows:
xyplot(lagy ~ n | rho1 * rho2, data= data, layout=c(2,6), span = 1,
xlab = "Sample Size", ylab = "Bias in the Coefficient for the Lag of X",
type = "o")
rho1 is a four level factor
2010 Jan 21
1
correlation significance testing with multiple factor levels
[Apologies in advance if this is too "statistics" and not enough "R".]
I've got an experiment with two sets of treatments. Each subject either received
all treatments from set A or all treatments from set B.
I can compute the N pairwise correlations for all treatments in either set using
cor(). If I take the mean of these N pairwise correlations, I see that the
effects
2007 May 14
2
creating a "list of 3 dataframes" from a "list of 2 dataframes" and a dataframe?
#I wish to create a "list of three dataframes" ("results2") from a "list of two dataframes" (temp) and a dataframe ("c")?
#Please advise.
a <- data.frame(x=c(1,2,3),y=c(5,7,9))
b <- data.frame(x=c(2,4,7,9),y=c(2,3,5,4))
c <- data.frame(x=c(22,34,7,9),y=c(52,63,5,4))
results1 <- list(a,b,c) #what I want
#but this is how I need to get there
2011 Aug 15
2
Extracting information from lm results (multiple model runs)
Just to inform:
I posted that before in R-sig-ecology but as it might be interesting also for other useRs, I post it also to the general r-user list:
Hello Alexandre,
thank you very much. I also found another way to extract summarizing information from lm results over e.g. 1000 repeated model runs:
results2 <- t(as.data.frame(results))
summary(results2)
Although some questions popped up in
2006 Jul 19
4
sorting and pagination
Hello All,
Okay i think I''m finally getting all of what i want out of ferret
working, thanks mostly to reading this forum and also getting ALOT of
questions answered, thanks alot everyone. Anyway my last ferret task is
too get the results sorted by a field called date_registered and have
this working with pagination.
here is what i''m doing at the moment:
2012 Feb 08
1
How indices calculated in package "boot"
Hi,there,
I am using R package "boot" to bootstrap. I have one question here: does
anybody possibly know how the boot package generates the "indices" which is
used in the statistic function?
I thought "indices = sample(data, replace=TRUE)", but when I replaced
"indices" with this command and used "boot", I got different results.
Specifically,
2010 Nov 18
1
how do I build panel data/longitudinal data models with AR terms using the plm package or any other package
Hi All,
I am doing econometric modeling of panel data (fixed effects). We currently use Eviews to do this, but I have discovered a bug in Eviews 7 and am exploring the use of R to build panel data models / longitudinal data models. I looked at the plm package but do not see how I can incorporate AR terms in the model using the plm package. I have an Eviews model with two AR terms, AR(1) and
2007 Jul 16
1
question about ar1 time series
Hello everybody,
I recently wrote a "program" that to generate AR1 time series, here the code:
#By Jomopo. Junio-2007, Leioa, Vizcaya
#This program to create the AR1 syntetic series (one by one)
#Where the mean is zero, but the variance of the serie AR1 and
#the coef. of AR1 are be changed. If var serie AR1 = 1 then is standarized!
#Final version for AR1 time series program
#Mon Jul
2009 Jul 28
3
Help with significance. T-test?
Hi,
this is more a general statistics question I think.
I am working on a system which automatically answers user questions (such
systems are commonly called "Question Answering systems").
I evaluated different versions of the same system on a publicly available
test set.
This set contains 500 question. Naturally, for each question the answer can
be wrong or right, which is coded as
2011 Nov 29
2
aggregate syntax for grouped column means
I am calculating the mean of each column grouped by the variable 'id'.
I do this using aggregate, data.table, and plyr. My aggregate results
do not match the other two, and I am trying to figure out what is
incorrect with my syntax. Any suggestions? Thanks.
Here is the data.
myData <- structure(list(var1 = c(31.59, 32.21, 31.78, 31.34, 31.61, 31.61,
30.59, 30.84, 30.98, 30.79, 30.79,
2015 Jun 26
1
[R-pkg-devel] Guidelines for S3 regression models
Stephen,
thanks for your effort. The more appropriate list for this discussion is
probably R-devel (as far as I understand it) so I've moved the discussion
there.
Related topics have already been discussed in the past. Specifically, I
remember contributions by Paul Johnson ("rockchalk" package) and John Fox
("effects" and "car" package) as their packages
2008 Feb 08
0
User specified correlation structure (e.g., 2-banded Toeplitz)
Dear All:
I am trying to fit a special case of a 2-banded Toeplitz correlation
structure. A 2-banded Toeplitz has ones on the diagonal, a
correlation, RHO1, on the first off-diagonal, and a correlation, RHO2,
on the second off-diagonal, with zeros on all subsequent
off-diagonals. After reading relevant sections in Mixed-Effects
Models in S and S-PLUS (Pinheiro & Bates, 2000) and searching
2008 Feb 08
0
User-specified correlation structure (e.g., 2-banded Toeplitz)
Dear All:
I am trying to fit a special case of a 2-banded Toeplitz correlation
structure. A 2-banded Toeplitz has ones on the diagonal, a
correlation, RHO1, on the first off-diagonal, and a correlation, RHO2,
on the second off-diagonal, with zeros on all subsequent
off-diagonals. After reading relevant sections in Mixed-Effects
Models in S and S-PLUS (Pinheiro & Bates, 2000) and searching
2008 Feb 12
0
nlme & special case of corARMA?
Dear All:
I am trying to fit a special case of a 2-banded Toeplitz correlation
structure. A 2-banded Toeplitz has ones on the diagonal, a
correlation, RHO1, on the first off-diagonal, and a correlation, RHO2,
on the second off-diagonal, with zeros on all subsequent
off-diagonals. After reading relevant sections in Mixed-Effects
Models in S and S-PLUS (Pinheiro & Bates, 2000) and searching
2011 Sep 10
0
npreg: plotting out of sample, extremely large bandwidths
Hello r-help,
I am using the excellent np package to conduct a nonparametric kernel
regression and am having some trouble plotting the results.
I have 2 covariates, x1 and x2, and a continuous outcome variable y. I
am conducting a nonparametric regression of y on x1 and x2. The one
somewhat unusual feature of these data is that, to be included in the
dataset, x1 must be at least as large as x2.
2009 Aug 07
1
Gauss-Laguerre using statmod
I believe this may be more related to analysis than it is to R, per se.
Suppose I have the following function that I wish to integrate:
ff <- function(x) pnorm((x - m)/sigma) * dnorm(x, observed, sigma)
Then, given the parameters:
mu <- 300
sigma <- 50
m <- 250
target <- 200
sigma_i <- 50
I can use the function integrate as:
> integrate(ff, lower= -Inf, upper=target)
2010 Aug 04
2
by group testing
Hello,
I have a data set which is similar to the following data
mice <- rep(letters[1:4],10)
outcome <- sample(c(0,1),length(mice),replace=T)
group <- c(rep("A",length(mice)/2),rep("B",length(mice)/2))
my.data <- data.frame(mice,outcome,group)
my.sort.data <- my.data[order(my.data[,1]),]
I would like to test wether there is a different between group A and B
2011 Feb 15
0
Delta method using numerical derivatives
Dear all,
Is there a fairly general R implementation of the delta method that uses
numerical derivatives?
I realise that the delta method has been implemented using symbolic
derivatives (e.g. alr3::delta.method, emdbook::deltamethod,
msm::deltamethod and survey:::nlcon), however possibly non-linear
estimators using the delta method with numerical derivatives can be
quite useful (e.g. predictnl