Hi all,
My replication paper was originally run in SAS. I am trying to replicate an
OLS. I am getting the same t-values, but different coefficients and standard
errors. Any ideas why this may be the case?
Best,
Viridiana R?os
617-997-2471
Hi all,
We still do not understand the expected values calculations in parts
c-e. The problem set asks us to use observed values of pressure (all
23 of them?) while the section code sets the other Xs at their mean
values. The second approach makes sense to us since we would have 1000
betas applied to each of mean values of pressure and the proposed
value of temperature. However, if we use all 23 observed values, then
each set of betas gets applied to each observation, and we end up with
23 probabilities for each draw of betas. The next step of what to do
with these n probabilities is unclear. Can anyone clarify the next
step? How does this approach differ from using the mean value of
pressure?
Jon and Jane
I'm a little confused by the graph in (e). If I just naively plot the
realizations from a bunch of Bernoulli random varibles, I get rows of
points corresponding to the O-ring failing and it not failing. Thus the
graph is not very informative. Would it be more appropriate to think of
the predicted values as part of a Binomial random variable (with trials
fixed), and graphing the number of O-ring failures in that group?
Martin
--
Martin Sparre Andersen, MPH
Harvard University
Program in Health Policy
anders4 at fas.harvard.edu
martin.andersen at aya.yale.edu
AIM: AndersenEPH
Community of Science: http://myprofile.cos.com/msa25cu
Hi Jens and Jenn,
Is today's replication help section taking place in the usual rooms we use
for Thursday sections?
Thanks!
Cat
On Wed, Mar 19, 2008 at 11:03 PM, Keith Schnakenberg <
keith.schnakenberg at gmail.com> wrote:
> I thought I had done c correctly, but my results do not match
> zelig's. I calculated the first difference at each value of pressure
> and then averaged them. Is this the right concept?
> _______________________________________________
> gov2001-l mailing list
> gov2001-l at lists.fas.harvard.edu
> http://lists.fas.harvard.edu/mailman/listinfo/gov2001-l
>
>
--
Catherine Lena Kelly
Ph.D. Student
Harvard University Department of Government
Hi all,
It appears that Zelig forces R to round numbers fairly strictly such
that 466.543 will always be 466, even if you try to get R to keep more
decimals. Why does Zelig do this? Is there a way to turn this off in
Zelig or to detach the library?
--
Jon Bischof
Graduate Student
Department of Government
Harvard University
Does anyone know how to put a data set from stata version 9 into R. When I try
to use the code that is similar to this,
library(foreign); dat <- read.dta("P:/Gov2001/leader.dta")
it says error not a stata v. 5-8. dta file
Is there any way to just copy and paste the data into R?
Hi,
I'm having trouble getting optim to work in Part B. My code is as follows:
opt.logit <- optim(c(0,0,0), logit.fn, x=X, y=Y, method="BFGS",
control=list(fnscale=-1), hessian=T)
My logit function takes par, x and y; X is a matrix with 1, x1 and x2, and Y
is a vector. I can't see what I'm doing wrong so any help would be most
appreciated!
Thanks,
Marcy
--
Marcy E. McCullaugh
Ph.D. student
Department of Political Science
University of California, Berkeley
210 Barrows Hall
Berkeley, CA 94720
Exchange Scholar 2007-08
Department of Government and
Davis Center for Russian and Eurasian Studies
Harvard University
1730 Cambridge Street, 3rd Floor
Cambridge, MA 02138
Hi Jenn, Jens,
Any advise on what observed value of preassure we have to use when there is
not observed value at a particular temperature? Should we go with the mean
value?
Best,
Viridiana R?os
617-997-2471
This week's problem set doesn't specify whether we should include confidence
intervals or a rug in our plots for part e. Does anyone know whether we're
expected to include them as we do for part d?
