Thank you Rolf,
>> Using the analysis of co-variance example from MASS (fourth edition, p
>> 142), what is the correct notation for the formula "Gas, ~ Insul/Temp
> There shouldn't be a comma after ``Gas'' in that formula.
>> - 1"? Obviously, if we fit it as two separate models (as in the
>> exa
Dear list, I am currently writing up some of my R models in a more
formal sense for a paper, and I am having trouble with the notation.
Although this isn't really an 'R' question, it should help me to
understand a bit better what I am actually doing when fitting my
models!
Using the analysis of co
Dear list, I'm wondering if anyone can help me calculate the deviance
of either a zeroinfl or hurdle model from package pscl?
Even if someone could point me to the correct formula for calculating
the deviance, I could do the rest on my own.
I am trying to calculate a pseudo-R-squared measure based
Hello list,
I am not sure if the terminology that I am using here is widely used,
however, I provide an example in the hopes that my problem will become
clear. My basic problem is that I am unsure of how to 'constrain' my
model estimates to reproduce the aggregate (by factor levels) observed
depen
Hmm, looks like I'm 'answering' my own question here...
library(Matrix)
data(KNex)
mm <- KNex$mm
str(mmQR <- qr(mm))
# new stuff:
R <- mmQR@R
Rdiag <- diag(R)
rank <- sum(Rdiag > max(dim(mm))*.Machine$double.eps*abs(R[1,1])) #
this is the matlab default I think?
# 712
for comparison, rankMatrix f
Dear list,
Can anyone tell me how to obtain the rank of a sparse Matrix, for
example from package Matrix (class dgCMatrix)? Here is an example of
QR decomposition of a sparse matrix (from the sparseQR class help).
library(Matrix)
data(KNex)
mm <- KNex$mm
str(mmQR <- qr(mm))
Similarly, using the
Dear list,
I have been working with the MatrixModels package quite a bit this
week, and it is proving to be extremely valuable for my current work
(I am working with several factors with many levels, leading to a
sparse model matrix). However, as my knowledge of statistical theory
leaves much to b
Thanks for the reply Christian,
> I have never used mmlcr for this, but quite generally when fitting such
> models, the likelihood has often very many local optima. This means that the
> result of the EM (or a similar) algorithm depends on the initialisation,
> which in flexmix (and perhaps also i
Dear list,
I have been comparing the outputs of two packages for latent class
regression, namely 'flexmix', and 'mmlcr'. What I have noticed is that
the flexmix package appears to come up with a much better fit than the
mmlcr package (based on logLik, AIC, BIC, and visual inspection). Has
anyone e
Hello list,
Has anyone had any luck creating an M-step driver for negative
binomial regression for use with package flexmix? I've had a look
here: http://cran.r-project.org/web/packages/flexmix/vignettes/flexmix-intro.pdf
as well as poking around in the flexmix source, but I haven't had much
luck
Dear list,
I posted essentially this same question to the r-sig-geo mailing list
last week with no response :( Unfortunately I am no closer to reaching
a solution, so I now post it here (with some clarifications) in the
hope that someone following this list might have an answer for me:
Has anyone
Dear list,
I am trying to plot a radial dendrogram using the ape package, which
requires my data to be of class 'phylo'. Currently I have my
dendrogram stored as an object of class 'dendrogram' which was
produced from an outside bit of C code, but was made into an object of
class 'igraph.eigenc' a
Hello List,
Is there a faster way to set values in one data.frame equal to NA
conditional on the corresponding value in another data.frame? Currently
I am using:
> b[is.na(a)] <- NA
where 'a' and 'b' are data.frames of equal size/dimensions, and 'a'
contains NAs but 'b' does not. This is extr
Dear List,
I am looking for an efficient method for replacing values in a
data.frame conditional on the values of a separate data.frame. Here is
my scenario:
I have a data.frame (A) with say 1000 columns, and 365 rows. Each cell
in the data.frame has either valid value, or NA. I have an additional
ion and maybe we can help
On 1/28/08, Carson Farmer [1]<[EMAIL PROTECTED]> wrote:
Rolf Turner wrote:
On 26/01/2008, at 10:54 AM, Carson Farmer wrote:
Dear List,
I am attempting to perform a harmonic analysis on a time series of snow
depth, in which the annual curve is essentially a
Rolf Turner wrote:
>>
>> On 26/01/2008, at 10:54 AM, Carson Farmer wrote:
>>
>>> Dear List,
>>>
>>> I am attempting to perform a harmonic analysis on a time series of snow
>>> depth, in which the annual curve is essentially asymmetric (i.e. sno
Dear List,
I am attempting to perform a harmonic analysis on a time series of snow
depth, in which the annual curve is essentially asymmetric (i.e. snow
accumulates slowly over time, and the subsequent melt occurs relatively
rapidly). I am trying to fit a curve to the data, however, the actual
Hello R community,
Does anyone know of a package that will perform cycle regression
analysis? I have searched the R-help archives etc. but have come up with
nothing so far.
If I am unable to find an existing R package to do so, is there anyone
familiar with fitting sine functions to data. My p
18 matches
Mail list logo
