Displaying 15 results from an estimated 15 matches for "pdowney".
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downey
2010 Jun 22
5
Displaying Iteration Count
Hello,
I'm running a very long for loop that usually takes hours. For my own piece
of mind, it would be nice if I could check periodically and see which
iteration the loop is on. A line of code that told R to print the iteration
number every 100 or 200 iterations would be perfect.
Does anyone know something like this? I've never known how to print
anything within a for loop before the
2011 May 17
2
Minimum value by ID
Hello,
I have a longitudinal dataset where each individual has a different number
of entries. Thus, it is of the following structure:
x <- runif(12)
id.var <- factor(c(rep("D1",4),rep("D2",2),rep("D3",3),rep("D4",3)))
dat <- as.data.frame(x)
dat$id.var <- id.var
dat
> dat
x id.var
1 0.9611269 D1
2 0.6738606 D1
3
2011 Sep 23
4
'save' saved object names instead of objects
Hello,
I created an array to hold the results of a series of simulations I'm
running:
d.eta <- array(0,dim=c(3,3,200))
<simulation goes here and populates the array but it's not important>
Then I tried to save the results using this:
save(d.eta,file="D:/Simulation Results/sim 9-23-11 deta")
When I later tried to reload them using this:
d.eta <-
2010 Mar 11
0
Constraining coefficients to be equal in svar
...et
Impulse Response Functions, so I don't need any fancy cointegration or
error correction techniques or any of that).
Thanks.
P. Mitchell Downey | Research Associate II
Justice Policy Center | Urban Institute
2100 M. Street N.W. | Washington, DC 20037
T: (202) 261-5329 | F: (202) 659-8985
PDowney at urban.org | www.urban.org
2011 Feb 25
1
Hierarchical Power Analysis
Hello,
A colleague is trying to do a fairly complicated power analysis for a
project. The project would be evaluating random assignment to one of three
conditions within each of 8 sites. The dependent variable would be binary
(we do not care at this point whether it would be analyzed with logit or
probit).
We can simulate the data in a bunch of iterations and do analyses in each
iteration, but
2011 May 29
1
Setting max. iterations for lmer
Hello,
I hate to ask a question which is directly addressed in the documentation,
but can someone please give me an example of how to change the maximum
number of iterations used by lmer. I'm having a hard time understanding
this:
control a list of control parameters. See below for details.
control
a named list of control parameters for the estimation algorithm, specifying
only
2011 Jul 01
2
merge function
Hello,
I'm clearly confused about the merge function. In the following
r <- merge(x,y,all.x=T,all.y=F)
my y vector has only unique values (no duplicates). So I don't understand
how this can ever generate an r which is of greater length than x.
I thought the default behavior was only matching rows are included, but
that using all.x=T included rows with unmatched x's as well. If
2012 Mar 08
1
Panel models: Fixed effects & random coefficients in plm
Hello,
I am using {plm} to estimate panel models. I want to estimate a model that
includes fixed effects for time and individual, but has a random individual
effect for the coefficient on the independent variable.
That is, I would like to estimate the model:
Y_it = a_i + a_t + B_i * X_it + e_it
Where i denotes individuals, t denotes time, X is my independent variable,
and B (beta) is the
2011 Nov 09
2
Installing binaries from R-Forge
Hello,
I'm attempting to install the splm package from R-Forge.
https://r-forge.r-project.org/R/?group_id=352
The page says, "In order to successfully install the packages provided on
R-Forge, you have to switch to the most recent version of R..." It later
says "To install this package directly within R type:
install.packages("splm",
2010 Aug 13
6
Equality of Vectors
Hello,
Is there a way to get a single TRUE or FALSE statement from comparing two
vectors? For example,
c(1,2,3) == c(1,2,3)
produces
TRUE TRUE TRUE
where I would like it to produce only
TRUE
for use in an if statement.
Likewise, when two vectors are not exactly identical (in all elements) I
would like a single FALSE result, as opposed to
c(1,2,3) == c(1,2,5)
TRUE TRUE FALSE
Any ideas?
2010 Apr 12
1
Strange results from Multivariate Normal Density
Hello,
I'm using dmnorm from the package {mnormt} and getting strange results.
First, according to the documentation, dmnorm should return a vector of
densities, and I'm only getting one value returned (which is what I would
expect). I've been interpreting this as the joint density of all values in
the x vector (which is what I want). Should a vector of densities be
returned, and if
2011 Feb 16
0
Arima contents
Hello,
I'm running a number of arima models using the "arima" function. Often,
when lag length gets too high, these model don't converge and an error
message appears as this:
> reg <- arima(y,order=c(7,0,7),xreg=isr)
Warning message:
In arima(y, order = c(7, 0, 7), xreg = isr) :
possible convergence problem: optim gave code=1
In this case, when you print the results
2010 Mar 11
1
VAR with contemporaneous effects
Hi,
I would like to estimate a VAR of the form:
Ay_t = By_t-1 + Cy_t-2 + ... + Dx_t + e_t
Where A is a non-diagonal matrix of coefficients, B and C are matricies of
coefficients and D is a matrix of coefficients for the exogenous variables.
I don't think the package {vars} can do this because I want to include
contemporaneous cross-variable impacts.
So I want y1_t to affect y2_t and I
2011 Jun 01
0
Simulating SVAR Data
Hello,
I'd like to simulate data according to an SVAR model in order to
demonstrate how other techniques (such as arima) yield biased estimates. I
am interested in a 2 variable SVAR with 2 lags (in the notation of the vars
vignette, K = 2, P = 2, where B = I_K). I'm using the {vars} package
outlined here:
http://cran.r-project.org/web/packages/vars/vignettes/vars.pdf
I thought that the
2010 Apr 19
2
ecdf
Hello,
I'd like to plot an empirical cumulative distribution function, except
instead of the fraction of values < x, I'd like the fraction of values > x.
I think this can be done using the ecdf function in {Hmisc}. I installed
the package and loaded it. However, when following the example given in the
documentation, I get an error:
x <- rnorm(100)
ecdf(x,what='1-F')