gmane.comp.lang.r.zelig

Value for log(oratio) in "blogit" model

David Auty — 2012-05-09T20:27:24

Hi there,

I'm fitting a bivariate logistic (blogit) model using Zelig and would like to use the equations given in the documentation to hard code some predictions, and to understand further how the model works.  The problem is that while it is easy to calculate the marginal probabilities, it is unclear from the documentation what value of psi to use in the equations for the joint probabilities. The documentation gives:

Odds ratio (psi )= exp(x3*beta3)

But we don't know what to substitute for x3 in this equation. Using exp((intercept):3) from the model does not give plausible answers, which leads us to assume we are missing something obvious and important.

Have searched the archives and also the VGAM documentation with no luck, so would be grateful for any pointers.

R2.15.0 on Windows 7.

Thanks in advance for any help.

Regards,

David Auty
Stagiaire Postdoctoral
Département des sciences du bois et de la forêt
Université Laval
Québec (QC) G1V 0A6

Gamma regression

Salvador Becerra-Munoz — 2012-04-30T20:53:45

Please I need your help!

This code sometimes predicts negative values because it is based on the inverse 
link. What is the modification to calculate de parameters using the loglink 
option?



 z.out = zelig(PT ~ Q + S + T + TDG, model = "gamma", data = PT)
 summary(z.out)
 x.out = setx(z.out)
 s.out = sim(z.out, x = x.out)
 plot(s.out)



 Thanks a lot for your advice

Conditional Frailty Models in Zelig

Brenton Peterson — 2012-04-27T01:20:25

Hi,

I am trying to estimate a conditional frailty survival model, as in
Box-Steffensmeier,  et al (2007 Political Analysis).  I have run them
previously in R but would like to implement them in Zelig for
post-estimation purposes.  Is there a way to do this?  While the Cox PH
with time-varying covariates is closest to my needs, it does not completely
fit the bill.  Is this an option in the current Zelig version?

Thanks,
B Peterson

Cox Proportional Hazards Regression

Johannes Castner — 2012-04-08T03:15:31

To whom this may concern,

I am trying to run a Cox Proportional Hazards Regression in the 
following way, using Zelig:

z.out <- zelig(Surv(duration, Censored) ~ Ethnic1 + Type + Year1, model 
= "coxph", data = data)

but I get the following error:

Error in fitter(X, Y, strats, offset, init, control, weights = weights,  :
   NA/NaN/Inf in foreign function call (arg 6)
In addition: Warning message:
In fitter(X, Y, strats, offset, init, control, weights = weights,  :
   Ran out of iterations and did not converge

Does anyone know just what that means and how I can get around it?

Johannes

AUTO: Tom Aldenberg is out of the office (returning Fri04/13/2012)

Tom Aldenberg — 2012-04-06T09:48:24

I am out of the office from Sat 03/31/2012 until Fri 04/13/2012.




Note: This is an automated response to your message  "Zelig Digest, Vol 20,
Issue 1" sent on 5-4-2012 18:00:02.

This is the only notification you will receive while this person is away.

readRDS

Matthias Kretschmer — 2012-04-04T19:13:37

I tried to install Zelig on R 2.15 (on a Windows 7, 64bit machine) and keep
getting an error message:

*Error : .onAttach failed in attachNamespace() for 'Zelig', details:
  call: NULL
  error: '.readRDS' is defunct.
Use 'readRDS' instead.
See help("Defunct")
Error: package/namespace load failed for ‘Zelig’
*
Any idea what that means?

Matthias

Plot.ci function to logit.survey

Rogério Barbosa — 2012-03-02T20:16:26

Hey all again,

I would like to inform that the most updated version of plot.ci function
doesn't have the item "logit.survey" listed on its algorithm. So it is not
possible to plot confidence intervals for predicted values calculated using
this model.

I tried to make that inclusion myself -- and it worked.

Here it goes the modified function.
(I found the original at:
http://r.iq.harvard.edu/src/contrib/Zelig/R/plot.ci.R)

Best,





plot.ci <- function(x, CI=95, qi = "ev", main = "",

                    ylab = NULL, xlab = NULL, xlim = NULL,

                    ylim = NULL, col = c("red", "blue"), ...) {

  "%w/o%" <- function(x,y) x[!x %in% y] #--  x without y

  if (class(x) != "zelig")

    stop(" plot.ci() works only for sim() output.")

  if (!(x$zelig.call$model) %in%

        c("ls", "logit",* "logit.survey"*, "normal.survey","probit", "exp",
"gamma", "lognorm",

          "weibull", "normal", "poisson", "tobit", "relogit",

          "negbin", "logit.bayes", "probit.bayes",

          "poisson.bayes", "normal.bayes", "tobit.bayes",

          "ls.mixed", "logit.mixed", "probit.mixed",

          "gamma.mixed", "poisson.mixed",

          "logit.gam", "gamma.gee", "normal.gam", "poisson.gam",

          "probit.gam", "logit.gee", "normal.gee",

          "poisson.gee", "probit.gee", "normal.survey"))

    stop("\n  plot.ci() is valid only for non-categorical, univariate
response models.")

  cip <- c((100-CI)/200, 1-(100-CI)/200)

  summarize <- function(z, cip){

    res <- NULL

    res <- cbind(res, apply(z, 2, quantile, prob=cip[1]))

    res <- cbind(res, apply(z, 2, quantile, prob=cip[2]))

    res

  }

  vv <- apply(x$x, 2, unique)

  idx <- sapply(vv, length)

  cidx <- which(idx > 1)

  if (!is.null(x$x1)) {

    vv1 <- apply(x$x1, 2, unique)

    idx1 <- sapply(vv1, length)

    cidx1 <- which(idx1 > 1)

    if (!identical(names(idx), names(idx1)))

      stop("variables in x and x1 do not match.")

    ## Checking for one dimension of variation, including interaction terms

    if (length(cidx) > length(cidx1)) {

      tmp <- names(idx)[cidx %w/o% cidx1]

      tmp1 <- names(idx)[cidx[cidx %in% cidx1]]

    }

    else {

      tmp <- names(idx1)[cidx1 %w/o% cidx]

      tmp1 <- names(idx1)[cidx1[cidx1 %in% cidx]]

    }

  check <- grep(tmp1, tmp)

  if (length(check) != length(tmp))

    stop("x and x1 vary on more than one dimension.")

  }

  var <- vv[[cidx[1]]]

  q <- pmatch(qi, names(x$qi))

  qofi <- x$qi[[q]]

  sum.qi <- summarize(qofi, cip)

  if (!is.null(x$x1) && qi == "ev") {

    fd <- x$qi$fd

    ev1 <- fd + qofi

    sum.qi1 <- summarize(ev1, cip)

  }

  else sum.qi1 <- NULL

  if (is.null(ylab))  ylab <- x$qi.name[[q]]

  if (is.null(xlab))  xlab <- paste("Range of", colnames(x$x)[cidx[1]])

  if (is.null(ylim)) {

    if (is.null(sum.qi1))  ylim <- c(min(sum.qi), max(sum.qi))

    else  ylim <- c(min(sum.qi, sum.qi1), max(sum.qi, sum.qi1))

  }

  if (is.null(xlim))  xlim <- c(min(var), max(var))

  plot.default(var, type = "n", ylab = ylab, main = main, xlab = xlab,

               xlim = xlim, ylim = ylim)

  for (i in 1:length(var)) {

    lines(c(var[i], var[i]), c(sum.qi[i,1], sum.qi[i,2]), col = col[1], ...)

    if (!is.null(x$x1) && qi == "ev")

      lines(c(var[i], var[i]), c(sum.qi1[i,1], sum.qi1[i,2]), col = col[2],
...)

  }

}





- - - - -
Rogério J. Barbosa
Researcher at Centre for Metropolitan Studies/Cebrap
São Paulo - Brazil

setx "incorrect number of dimensions" error

Rogério Barbosa — 2012-03-02T04:06:02

Hey all,

I get this error when I run setx: "Error in dta[complete.cases(mf),
names(dta) %in% vars, drop = FALSE] : incorrect number of dimensions"
I found some people with the same problem on internet - but apparently no
one has worked it out.
Does anyone know how to solve it?

My output is bellow the message.

Thanks,
Rogério Barbosa


data = pad)
How to cite this model in Zelig:
Kosuke Imai, Gary King, and Oliva Lau. 2008. "logit: Logistic Regression
for Dichotomous Dependent Variables" in Kosuke Imai, Gary King, and Olivia
Lau, "Zelig: Everyone's Statistical Software,"
http://gking.harvard.edu/zelig


*Error in dta[complete.cases(mf), names(dta) %in% vars, drop = FALSE] : *
*  incorrect number of dimensions*



Rogério J. Barbosa
Researcher at Centre for Metropolitan Studies/Cebrap
São Paulo - Brazil

Error with ls.mixed and weights

Harden, Jeff — 2012-02-27T18:44:53

Hello,

I am having problems with the "ls.mixed" model in zelig() and the weights argument. This is similar to the problem documented here: https://lists.gking.harvard.edu/pipermail/zelig/2011-July/000183.html. However, while it seems like the issue in that thread was missing values on the dependent variable, I am having the issue with no missing data. I can estimate the model with weights using lmer(), but not using zelig(). I have an example that reproduces this error using fake data posted here: http://pastebin.com/29KbmRZD and listed below.

##
library(Zelig)
set.seed(1000)

x <- runif(1000, -1, 1)
y <- x + rnorm(1000)
wt <- rexp(1000)
id <- rep(1:20, times = 50)
d <- as.data.frame(cbind(y, x, wt, id))

m1 <- zelig(y ~ x + tag(1|id), model = "ls.mixed", weights = "wt", data = d)
m2 <- lmer(y ~ x + (1|id), weights = wt, data = d)
##

Thanks for any insight with this problem.

Jeff Harden


---
Jeffrey J. Harden
Ph.D Candidate, Department of Political Science
Program Coordinator, American Politics Research Group (APRG)
University of North Carolina at Chapel Hill
jjharden-gpQNmkgQrW4< at >public.gmane.org<mailto:jjharden-gpQNmkgQrW4< at >public.gmane.org>
http://jjharden.web.unc.edu/

Error in sim()

Brad Epperly — 2012-02-23T03:52:21

Hey all,

I developed a problem today, and couldn't seem to solve it (I say today
because I use Zelig regularly, including yesterday, and this wasn't an
issue). But I've found it and am now able to replicate it, so thought I
should share it and see if others have this problem.

If I have the arm package loaded with Zelig and try to execute a command
like the folllowing:


I get the following error:

Error in .local(object, ...) :
  unused argument(s) (x = list(`(Intercept)` = c(1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1), Legal_Infra_lag1 =
c(2.58489978735531, 2.58489978735531, 2.58489978735531, 2.58489978735531,
2.58489978735531, 2.58489978735531, 2.58489978735531, 2.58489978735531,
starting httpd help server ... done

This is not a function of my data: even the demos for the different model
types, e.g. demo("ls.mixed") fail to work properly. If I unload the
armpackage all is well. In the process I updated everything, so this
isn't a
function of not-current packages or R not working together.

Any comments or tests are well-appreciated!

Brad Epperly
PhD Candidate
Department of Political Science
University of Washington
Box 353530
Seattle, WA 98195
http://sites.google.com/a/uw.edu/epperly/

ZeligMultinomial

Josue Guzman — 2012-02-15T16:59:02

*Please, let me know how can I install ZeligMultinomial package. I want to
use mlogit, which according to the manual (page 50), is found in said
package.

I tried with the command,
install.packages("ZeligMultinomial", repos="http://r.iq.harvard.edu/",
type="source")

But received the following message:
Warning: dependency 'MNP' is not available
trying URL '
http://r.iq.harvard.edu/src/contrib/ZeligMultinomial_0.5-4.tar.gz'
Content type 'application/x-gzip' length 9730 bytes
opened URL
==================================================
downloaded 9730 bytes

During startup - Warning messages:
1: Setting LC_CTYPE failed, using "C"
2: Setting LC_TIME failed, using "C"
3: Setting LC_MESSAGES failed, using "C"
4: Setting LC_PAPER failed, using "C"
ERROR: dependency 'MNP' is not available for package 'ZeligMultinomial'
* removing
'/Library/Frameworks/R.framework/Versions/2.14/Resources/library/ZeligMultinomial'

The downloaded packages are in

'/private/var/folders/UL/ULLu+bi5GR8IM1G-7XZBJU+++TI/-Tmp-/Rtmp6jw6M9/downloaded_packages'
Warning message:
In install.packages("ZeligMultinomial", repos = "http://r.iq.harvard.edu/",
:
  installation of package 'ZeligMultinomial' had non-zero exit status
***

plot.ci like ggplot2's "stat_smooth"?

Christoph Riedl — 2012-02-11T20:26:51

Hi!

I use Zelig's plot.ci() function quite a lot to generate plots like the 
one shown in the Zelig tutorial on p. 53 ("Effect of Education and Age 
on Voting Behavior"). (the one generated by "> demo(vertci)")

Is it possible to generate a plot of the estimated Zelig models that 
looks more like ggplot2's "stat_smooth"?
http://had.co.nz/ggplot2/stat_smooth.html

What I'm looking for is something that looks like this:
http://had.co.nz/ggplot2/graphics/8953194646b79f7e28d5bebd58b18616.png

Cheers,
Chris

sim(), Amelia, and quantities of interest with ls.mixed

Trey Causey — 2012-02-08T21:10:35

Hello all:

I have replicated this with the current (stable) and alpha releases of
Zelig. I cannot simulate quantities of interest using a mixed-effects
model estimated on data imputed with Ameila. setx() works fine, but
the sim command runs for a while and then reports it is unable to find
one of my predictor variables (variable names changed as they are
irrelevant). Code below:

model.full <- zelig(attitude ~ age + married + male + income + tag(1 |
state), model = "ls.mixed", data = imp$imputations,  REML = FALSE,
subset = wave4)

x.out <- setx(model.full)

simout <- sim(x.out, x = x.out)

The model estimates fine with the zelig() function, setx() works fine
in setting the explanatory variables at their means, but when I
attempt to use sim(), I get:

Error in eval(expr, envir, enclos) : object 'age' not found

A traceback produces this:

13: eval(expr, envir, enclos)
12: eval(predvars, data, env)
11: model.frame.default(object, data, xlev = xlev)
10: model.frame(object, data, xlev = xlev)
9: model.matrix.default(parsefml$fixed, data = D)
8: model.matrix(parsefml$fixed, data = D)
7: model.matrix(parsefml$fixed, data = D)
6: is.data.frame(x)
5: colnames(model.matrix(parsefml$fixed, data = D))
4: qi.mer(object[[1]], simpar = simpar, x = as.matrix(x), x1 = if
(!is.null(x1)) as.matrix(x1))
3: qi(object[[1]], simpar = simpar, x = as.matrix(x), x1 = if
(!is.null(x1)) as.matrix(x1))
2: sim.setx.MI(model.full, x = x.out)
1: sim(model.full, x = x.out)

Any suggestions?

Thanks very much,
Trey Causey

new version

Gary King — 2012-02-08T02:45:15

The Zelig <http://gking.harvard.edu/zelig> core team is thrilled to
announce the alpha release of Zelig Version 4.

*Summary:* This release includes a complete rewrite of almost every line of
Zelig code.  The changes are all infrastructural: If everything works as
planned, users won’t notice any changes today.  But this release makes
maintaining and improving Zelig much easier and so users should see major
improvements going forward.

*Shout Out: *The Zelig community owes Matt Owen <mowen-zvdtVsPQyYJu6/7BKvT5pw< at >public.gmane.org> huge
thanks for leading the development effort behind this new version; if a few
percent of the several hundred thousand Zelig users were to fill Matt's
mailbox with messages that said no more than "thanks", we wouldn't object!

*Details*: Designated as a "Developer Update", Zelig 4 offers a wide-range
of improvements to ease the process of adding new statistical models to the
already extensive Zelig statistical software suite.  This release is
packaged with a brand-new API, which greatly reduces the complexity and
length of Zelig's development functions - the zelig2, param and qi methods.
 Zelig also now includes a package-creator (zelig.skeleton) that operates
in the same vein as R's core function "package.skeleton".

In addition to changes in the development toolkit, Zelig has now been split
across 7 distinct packages. This change has been made to refine the scope
of Zelig and its add-ons. In particular, this restructuring of Zelig into a
full software suite allows developers to contribute, develop and repair
add-on packages without tinkering with the Zelig API and core
functionality.  (On the theory that you shouldn’t have to pull out the
spark plugs when you’re filling the tank!)

While this release's prime focus has been improving the developer toolkit
and restructuring the software suite, Zelig 4 offers an end-user experience
completely identical to previous versions. That is, zelig's basic functions
- zelig, setx and sim - remain unchanged in functionality for available
statistical models.

*New Features*

A revised developer API. The primary developer methods - zelig2, param and
sim - have been reimplemented to use a sleeker, simpler API. For
information, please read the Zelig developer's manual found here:
 http://zeligdev.github.com/files/booklet.pdf

The core package has been restructured and minimized. In particular, Zelig
core now contains only code essential to its operation, while all
non-essential tasks have been made into specific R-packages. For a complete
list of official Zelig packages, please refer to:
 https://github.com/zeligdev

Development tools for contributors have been added to the core package. In
particular, the "zelig.skeleton" function is packaged within Zelig-core in
order to facilitate the rapid development of new Zelig packages.

The Zelig software suite now includes 7 separate R-packages. This change
offers a simple and easy method for ensuring that development and
bug-fixing within any particular Zelig add-on will leave the remainder of
the Zelig software suite unchanged.

A hook API has been integrated into the core package, in order to reduce
the necessity to directly alter the zelig, setx and sim methods.

Roxygen-compliant documentation is now standard in all Zelig packages. This
offers an easy way to manage Rd documentation, dependencies and exports
from within the R code itself. That is, documentation is more tightly
paired with the actual R code. For more information about Roxygen, please
refer to:
 http://roxygen.org/

*GitHub*

Zelig is now on GitHub!  Fork an add-on package or contribute bug-finds
today!

For a full listing of official packages and their repositories, please see:
https://github.com/zeligdev

*Links
*
The main Zelig site:  http://gking.harvard.edu/zelig  or  j.mp/Zelig

The Zelig 4 development site:
* Website: http://zeligdev.github.com/
* Package Repositories: https://github.com/zeligdev/
* Installation Guide: http://zeligdev.github.com/files/zelig.pdf
* Zelig Manual: http://zeligdev.github.com/#install
* Available and Missing Add-on Packages: http://zeligdev.github.com/#models

*Questions
*
For *all* questions on Zelig, please send all mail to:
zelig-boHuZhbfW+Y6DHxCPSz5rL5+avTOL6Rl< at >public.gmane.org

Gary
--
*Gary King* - Albert J. Weatherhead III University Professor - Director,
IQSS - Harvard University
GKing.Harvard.edu <http://gking.harvard.edu/> - King-vbSkjhsARtCVc3sceRu5cw< at >public.gmane.org -
< at >kinggary<http://twitter.com/kinggary> -
617-500-7570 - Asst 495-9271 - Fax 812-8581

minor typos in documentation

Scott Kostyshak — 2012-02-01T06:16:28

Below are a few small typos in the current Zelig documentation, which I downloaded from here:
http://gking.harvard.edu/sites/scholar.iq.harvard.edu/files/zelig.pdf

*The ologit section has two exact (I think) copies:
11.44 and 11.52

*In the ologit section(s), the word "order" is repeated in
"If Y takes discrete integer values, the as.factor() command will order automatically order the values."

*There seems to be a latex/bibtex problem. Do a search for "author?".

Best,
Scott Kostyshak

problem with robust = TRUE

Shahrzad Sabet — 2012-01-28T22:49:29

Hi zelig folks,

I'm trying to run a set of probit regressions with robust standard errors,
but I repeatedly get the following error message:

Error in glm.control(robust = TRUE) : unused argument(s) (robust = TRUE)

I can't figure out what the problem is. The sandwich package is loaded. An
example of the code I am using is below.

Many thanks,
Shar

z.out <- zelig(binary_iv ~ age + educ + income_new + gender_new + white +
black + hispanic + union_member + dem + rep + indep + tv_foreign + ecknow +
import_mfg, model="probit", robust = TRUE, data = data)

Problem with sim() when using polynomial time in Zelig

Francois Maurice — 2012-01-22T01:18:00

Hi,
 
I posted on Pastebin.com a demo code to show a problem with sim(). The title on Pastebin is "Problem with sim() when using polynomial time in Zelig".
 
When I use Zelig with polynomial time in the random effect part (ls.mixed model), the following message appears:
 
        Error in .local(object, ...) : Code not written yet
 
There is no problem if I drop the polynomial time from the random part.
 
Thanks

François Maurice

ReLogit and Clusters

Christopher — 2012-01-19T16:08:13

I'm trying to find a way to 
have country clusters in a relogit analysis. 

I have country-year data 
and the countries are grouped 
by a numeric id variable "cid". 

I've tried including a list 
of options for robust such that my model is:

M1 <- zelig(violence ~ dem_age, 
model = "relogit", tau = 88/5480, 
data = data, 
robust = list(
method = 
"vcovHAC", 
order.by = ~data$cid, 
adjust = TRUE
))

However why I run "summary(M1)" I get an error:

Error in meatHAC
(x, order.by = order.by, prewhite = prewhite, weights = weights,  : 
  subscript out of bounds

Any thoughts on what is going on?
ReLogit for zelig would be really useful if it could incorporate clusters. 

Thanks
Christopher

sim() command error with MatchIt

Kenji Adachi — 2012-01-18T06:20:13

Dear all,

I am interested in using MatchIt for my research. (I am relatively new to
R, too.) To make myself familiar with the command, I've tried some samples
provided in the manual.  I believe I followed the steps as explained, but I
always get the same error message. What I did was as follows:


                    married + re74 + re75, method = "nearest", discard
                    = "hull.control", data = lalonde)



                  married + re74 + re75, data = match.data(m.out),
                  model = "ls")



Error in mvrnorm(num, mu = coef(object), Sigma = vcov(object)) :
incompatible arguments


I am using R version 2.14.1. I also updated Zelig and MatchIt for the
latest version.
I have completely no idea what I did wrong.  I would greatly appreciate it
if you would tell me what to do.

Best Regards,
Kenji Adachi

Problem with sim() when using polynomial time

Francois Maurice — 2012-01-05T16:16:42

Hi,
 
The sim() fonction gives me the following message :
 
     Error in .local(object, ...) : Code not written yet
 
The sim() object is not produce but the zelig() object is produce.
 
I'm trying to evaluate a causal effect in a longitudinal study with a mixed model after matching with MatchIt(). Here's the code :
 
z.nearest <- zelig(outcome ~ treat + T + T2 + T3 + tag(1 + T + T2 | ID.factor), data=matched.nearest.long, model="ls.mixed")
x.nearest.0 <- setx(z.nearest, fn=NULL, treat=0)
x.nearest.1 <- setx(z.nearest, fn=NULL, treat=1)
s.nearest <- sim(z.nearest, x=x.nearest.0, x1=x.nearest.1)
 
I'm using polynomial time with a random part. There is no problem when the random part is only made of one term like this:
 
z.nearest <- zelig(outcome ~ treat + T + T2 + T3 + tag(T | ID.factor), data=matched.nearest.long, model="ls.mixed")
 
I posted a problem this last summer about polynomial time, but at that time the problem was within Zelig itself. Zelig was not able to cope with polynomial time, but that problem seems resolved. Maybe the problem with sim() has a link with that one.
 
Thanks,
 
Françcois Maurice

Problem with sim() when using polynomial time

Francois Maurice — 2012-01-05T16:16:42

Hi,
 
The sim() fonction gives me the following message :
 
     Error in .local(object, ...) : Code not written yet
 
The sim() object is not produce but the zelig() object is produce.
 
I'm trying to evaluate a causal effect in a longitudinal study with a mixed model after matching with MatchIt(). Here's the code :
 
z.nearest <- zelig(outcome ~ treat + T + T2 + T3 + tag(1 + T + T2 | ID.factor), data=matched.nearest.long, model="ls.mixed")
x.nearest.0 <- setx(z.nearest, fn=NULL, treat=0)
x.nearest.1 <- setx(z.nearest, fn=NULL, treat=1)
s.nearest <- sim(z.nearest, x=x.nearest.0, x1=x.nearest.1)
 
I'm using polynomial time with a random part. There is no problem when the random part is only made of one term like this:
 
z.nearest <- zelig(outcome ~ treat + T + T2 + T3 + tag(T | ID.factor), data=matched.nearest.long, model="ls.mixed")
 
I posted a problem this last summer about polynomial time, but at that time the problem was within Zelig itself. Zelig was not able to cope with polynomial time, but that problem seems resolved. Maybe the problem with sim() has a link with that one.
 
Thanks,
 
Françcois Maurice