Displaying 20 results from an estimated 9000 matches similar to: "lack of memory for logistic regression in R?"
2007 May 14
1
Predicted values from a logistic model
Hello -
I apologize if this question is simple/obvious, but I couldn't find a
satisfactory answer online, and I am not very accustomed to working
with R (Matlab is my poison. :-)). Any help would be greatly
appreciated.
I have a model with a three-level factor and a continuous covariate.
The call I use is:
mymodel <- glm(Response ~ Factor_covariate + continuous_covariate -
1,
2009 Jun 15
0
books on Time serie
A time series text with a title that seems designed to hide its
wide scope is:
Forecasting with Exponential Smoothing
The State Space Approach
Hyndman, R.J., Koehler, A.B., Ord, J.K., Snyder, R.D.
Springer 2009.
This book is actually an excellent overview of time series theory,
ARIMA as well as state space. It is of course, in part, a manual
for the forecast and other packages in what has been
2009 Sep 30
5
Condition to factor (easy to remember)
Dear List,
creating factors in a given non-default orders is notoriously difficult to
explain in a course. Students love the ifelse construct given below most,
but I remember some comment from Martin M?chler (?) that ifelse should be
banned from courses.
Any better idea? Not necessarily short, easy to remember is important.
Dieter
data = c(1,7,10,50,70)
levs =
2002 Mar 17
2
using "by" and indicies
I sent this to the list last week, and haven't seen it pop up. Either
I deleted it when it did appear, or possibly it was destroyed as
spam...? If it did appear and I somehow missed it, appologies.
In a nutshell, can the function FUN supplied to by() deduce
what level of factor by() was on when FUN was called? I've
been digging through the functions, and can't see where the
2012 May 29
1
lattice: add a marginal histogram on top of the colorkey of a levelplot?
Lattice experts:
Can you think of a way to produce a levelplot as below and then add a histogram of the z variable to the top margin of the plot that would sit on top of the color key?
x <- seq(pi/4, 5 * pi, length.out = 100)
y <- seq(pi/4, 5 * pi, length.out = 100)
r <- as.vector(sqrt(outer(x^2, y^2, "+")))
grid <- expand.grid(x=x, y=y)
grid$z <- cos(r^2) *
2007 Apr 15
1
unable to find inherited method for function "edges", for signature "ugsh", "missing"
I am new to using S4 methods and have run into this problem (on Windows XP using R 2.4.1): I am writing a package in which I use the graph package. I define my own classes of graphs as:
setOldClass("graphsh")
setOldClass("ugsh")
setIs("ugsh", "graphsh")
(I know that I "should have" used setClass instead - and I will eventually - but right now
2011 Nov 15
1
equal spacing of the polygons in levelplot key (lattice)
Given the example:
R> (levs <- quantile(volcano,c(0,0.1,0.5,0.9,0.99,1)))
0% 10% 50% 90% 99% 100%
94 100 124 170 189 195
R> levelplot(volcano,at=levs)
How can I make the key categorical with the size of the divisions equally spaced in the key? E.g., five equal size rectangles with labels at levs c(100,124,170,189,195)?
Apologies if this is obvious.
-A
R> version
2013 Jan 24
4
Difference between R and SAS in Corcordance index in ordinal logistic regression
lrm does some binning to make the calculations faster. The exact calculation
is obtained by running
f <- lrm(...)
rcorr.cens(predict(f), DA), which results in:
C Index Dxy S.D. n missing
0.96814404 0.93628809 0.03808336 32.00000000 0.00000000
uncensored Relevant Pairs Concordant Uncertain
32.00000000
2009 Mar 03
1
repeated measures anova, sphericity, epsilon, etc
I have 3 questions (below).
Background: I am teaching an introductory statistics course in which we are
covering (among other things) repeated measures anova. This time around
teaching it, we are using R for all of our computations. We are starting by
covering the univariate approach to repeated measures anova.
Doing a basic repeated measures anova (univariate approach) using aov()
seems
1999 May 05
1
Ordered factors , was: surrogate poisson models
For ordered factor the natural contrast coding would be to parametrize by
the succsessive differences between levels, which does not assume equal
spacing
of factor levels as does the polynomial contrasts (implicitly at least).
This requires the contr.cum, which could be:
contr.cum <- function (n, contrasts = TRUE)
{
if (is.numeric(n) && length(n) == 1)
levs <- 1:n
2002 Dec 01
1
generating contrast names
Dear R-devel list members,
I'd like to suggest a more flexible procedure for generating contrast
names. I apologise for a relatively long message -- I want my proposal to
be clear.
I've never liked the current approach. For example, the names generated by
contr.treatment paste factor to level names with no separation between the
two; contr.sum simply numbers contrasts (I recall an
2018 Mar 24
1
Function 'factor' issues
I am trying once again.
By just changing
f <- match(xlevs[f], nlevs)
to
f <- match(xlevs, nlevs)[f]
, function 'factor' in R devel could be made more consistent and back-compatible. Why not picking it?
--------------------------------------------
On Sat, 25/11/17, Suharto Anggono Suharto Anggono <suharto_anggono at yahoo.com> wrote:
Subject: Re: [Rd] Function
2017 Oct 15
2
Function 'factor' issues
In R devel, function 'factor' has been changed, allowing and merging duplicated 'labels'.
Issue 1: Handling of specified 'labels' without duplicates is slower than before.
Example:
x <- rep(1:26, 40000)
system.time(factor(x, levels=1:26, labels=letters))
Function 'factor' is already rather slow because of conversion to character. Please don't add slowdown.
2011 May 15
5
Question on approximations of full logistic regression model
Hi,
I am trying to construct a logistic regression model from my data (104
patients and 25 events). I build a full model consisting of five
predictors with the use of penalization by rms package (lrm, pentrace
etc) because of events per variable issue. Then, I tried to approximate
the full model by step-down technique predicting L from all of the
componet variables using ordinary least squares
2009 Nov 10
3
NetCDF output in R
Dear CSAG R users,
I will be glad if someone can point out what I am doing wrong or not doing at all in this.
I am trying to write out netcdf file in R. I have 26 time step but only the first time step is written.
For example:
>library(ncdf)
>path <- '/home/work/'
>forecast <- open.ncdf(paste(path,'cam.1980.2005.nc',sep=""))
> fore <-
2009 Nov 10
3
NetCDF output in R
Dear CSAG R users,
I will be glad if someone can point out what I am doing wrong or not doing at all in this.
I am trying to write out netcdf file in R. I have 26 time step but only the first time step is written.
For example:
>library(ncdf)
>path <- '/home/work/'
>forecast <- open.ncdf(paste(path,'cam.1980.2005.nc',sep=""))
> fore <-
2008 Apr 28
1
error in summary.Design
Dear list,
after fitting an lrm with the Design package (stored as "mymodel") I
try running a summary, but I get the following error:
dim(mydata)
[1] 235 9
names(mydata)
[1] "id" "VAR1" "VAR2" "VAR3" "VAR4" "VAR5" "VAR6" "VAR7" "VAR8"
summary(mymodel)
Error in `contrasts<-`(`*tmp*`,
2007 Jun 10
1
R logistic regression - comparison with SPSS
Dear R-list members,
I have been a user of SPSS for a few years and quite new to R. I read
the documentation and tried samples but I have some problems to obtain
results for a logistic regression under R.
The following SPSS script
LOGISTIC REGRESSION vir
/METHOD = FSTEP(LR) d007 d008 d009 d010 d011 d012 d013 d014 d015
d016 d017 d018 d069 d072 d073
/SAVE = PRED COOK SRESID
2013 May 01
2
Factors and Multinomial Logistic Regression
Dear All,
I am trying to reproduce the example that I found online here
http://bit.ly/11VG4ha
However, when I run my script (pasted at the end of the email), I notice
that there is a factor 2 between the values for the coefficients for the
categorical variable female calculated by my script and in the online
example.
Any idea about where this difference comes from?
Besides, how can I
2007 Mar 20
1
Error in nlme with factors in R 2.4.1
Hi,
the following R lines work fine in R 2.4.0, but not in R 2.4.1 or any devel versions of R
2.5.0 (see below for details).
library(drc) # to load the dataset 'PestSci'
library(nlme)
## Setting starting values
sv <- c(0.43355869, 2.49963220, 0.05861799, 1.73290589, 0.38153146, 0.24316978)
## No error
m1 <-
nlme(SLOPE ~ c + (d-c)/(1+exp(b*(log(DOSE)-log(e)))),
fixed =