Displaying 20 results from an estimated 800 matches similar to: "dynamically specifying regressors/RHS variables in a regression"
2010 Feb 09
2
Model matrix using dummy regressors or deviation regressors
The model matrix for the code at the end the email is shown below.
Since the model matrix doesn't have -1, I think that it is made of
dummy regressors rather than deviation regressors. I'm wondering how
to make a model matrix using deviation regressors. Could somebody let
me know?
> model.matrix(aaov)
(Intercept) A2 B2 B3 A2:B2 A2:B3
1 1 0 0 0 0 0
2
2010 Jan 12
0
[Solved][Code Snippets] Dropping Empty Regressors
To make a long story short I was doing some in-sample testing in which some
dynamically created regressors would end up either all true or all false
based on the validation portion. In my case a new mainframe configuration
(this is a crappy way to handle a level shift but I do what I can.) So here
is the code snippet that finally let me pre-check my regressors and drop any
of them that were all
2012 Nov 14
0
Time Series with External Regressors in R Problems with XReg
Hello everyone,
Hope you all are doing great! I have been fitting arima models and
performing forecasts pretty straightforwardly in R.
However, I wanted to add a couple of regressors to the arima model to see if
it could improve the accuracy of the forecasts but have had a hard time
trying to do so.
I used the following R function:
arima(x, order = c(0, 0, 0),
seasonal = list(order = c(0, 0,
2009 Feb 12
2
beginner's question: group of regressors by name vector?
dear r-experts: there is probably a very easy way to do it, but it eludes
me right now. I have a large data frame with, say, 26 columns named "a"
through "z". I would like to define "sets of regressors" from this data
frame. something like
myregressors=c("b", "j", "x")
lm( l ~ myregressors, data=... )
is the best way to create new
2008 Jul 31
0
random effects mixed model, different regressors
Hi everybody,
I have built a model that includes subject ID as a random effect, and has a
continous variable (time) and I want to test whether the slope of this line
differs between treatments (this is tested with the interaction between
treatment and "time").
My question now is that I also want to include regressors that might explain
variation in this slope between subjects (and of
2005 May 19
1
logistic regression: differential importance of regressors
Hi, All. I have a logistic regression model that I have run. The
question came up: which of these regressors is more important than
another?
(I'm using Design)
Logistic Regression Model
lrm(formula = iconicgesture ~ ST + SSP + magnitude + Condition +
Expertise, data = d)
Coef S.E. Wald Z P
Intercept -3.2688 0.2854 -11.45 0.0000
ST 2.0871 0.2730 7.64
2005 Sep 06
0
MASS: rlm, MM and errors in observations AND regressors
Hello,
I need to perform a robust regression on data which contains errors in BOTH
observations and regressors. Right now I am using rlm from the MASS package
with 'method="MM"' and get visually very nice results. MASS is quite clear,
however, that the described methodologies are only applicable to
observation-error only data (p. 157, 4th Ed.). So here's the questions now:
2017 May 16
0
Wish for arima function: add a data argument and a formula-type for regressors
Hi,
Using arima on data that are in a data frame, especially when adding
xreg, would be much easier if the arima function contained
1) a "data=" argument
2) the possibility to include the covariate(s) in a formula style.
Ideally the call could be something like
> arima(symptome, order=c(1,0,0), xreg=~trait01*mesure0, data=anxiete)
( or arima(symptome~trait01*mesure0,
2003 Aug 27
1
Problem in step() and stepAIC() when a name of a regressors has b (PR#3991)
Hi all,
I've experienced this problem using step() and stepAIC() when a name of a
regressors has blanks in between (R:R1.7.0, os: w2ksp4).
Please look at the following code:
"x" <-
c(14.122739306734, 14.4831100207131, 14.5556459667089,
14.5777151911177,
14.5285815352327, 14.0217803203846, 14.0732571632964,
14.7801310180502,
14.7839362960477, 14.7862217992577)
2009 Mar 23
0
Scaled MPSE as a test for regressors?
Hi,
This is really more a stats question than a R one, but....
Does anyone have any familiarity with using the mean prediction
squared error scaled by the variance of the response, as a 'scale
free' criterion for evaluating different regression algorithms.
E.g.
Generate X_train, Y_train, X_test, Y_test from true f. X_test/Y_test
are generated without noise, maybe?
Use X_train, Y_train
2010 May 05
1
Predict when regressors are passed through a data matrix
Hi everyone,
this should be pretty basic but I need asking for help as I got stuck.
I am running simple linear regression models on R with k regressors where k
> 1. In order to automate my code I packed all the regressors in a matrix X
so that lm(y~X) will always produce the results I want regardless of the
variables in X. I am new to R but I found this advice somewhere so I guess
it is
2009 Dec 08
0
Holiday Gift Perl Script for US Holiday Dummy Regressors
##### BEGIN CODE ######
#!/usr/bin/perl
######
#
# --start, -s = The date you would like to start generating regressors
#--end, -e = When to stop generating holiday regressros
# --scope, -c = D, W for Daily or Weekly respectively (e.g. Does this week
have a particular holiday)
# --file, -f = Ummm where to write the output silly!
#
# **NOTE** The EOM holiday is "End of Month" for
2009 Jan 21
1
Joint significance of more regressors in summary
Dear All,
I was wondering if it is possible to generate a regression summary (it does
not matter at this stage if from an lm or for example a glm estimate) in
which to obtain the joint significance of a set of regressors?
Examples could be looking at the joint significance level of a polynomial,
or of a set of exogenous variables of which is of interest the linear
combination suggested by the
2013 May 02
2
ARMA with other regressor variables
Hi,
I want to fit the following model to my data:
Y_t= a+bY_(t-1)+cY_(t-2) + Z_t +Z_(t-1) + Z_(t-2) + X_t + M_t
i.e. it is an ARMA(2,2) with some additional regressors X and M.
[Z_t's are the white noise variables]
How do I find the estimates of the coefficients in R?
And also I would like to know what technique R employs to find the
estimates?
Any help is appreciated.
Thanks,
2010 Dec 16
1
predict.lm with new regressor names
Hi all,
Suppose:
y<-rnorm(100)
x1<-rnorm(100)
lm.yx<-lm(y~x1)
To predict from a new data source, one can use:
# works as expected
dum<-data.frame(x1=rnorm(200))
predict(lm.yx, newdata=dum)
Suppose lm.yx has been run and we have the lm object. And we have a
dataframe that has columns that don't correspond by name to the
original regressors. I very! naively assumed that doing
2008 May 28
1
Fixing the coefficient of a regressor in formula
Dear R users,
I want to estimate a Cox PH model with time-dependent covariates so I am
using a counting process format with the following formula:
Surv(data$start, data$stop, data$event.time) ~ cluster(data$id) + G1 +
G2 + G3 + G4 + G5 +G6
Gs represent a B-spline basis functions so they sum to 1 and I can't
estimate the model as is without getting the last coefficient to be NA,
which
2013 May 02
1
warnings in ARMA with other regressor variables
Hi all,
I want to fit the following model to my data:
Y_t= a+bY_(t-1)+cY_(t-2) + Z_t +Z_(t-1) + Z_(t-2) + X_t + M_t
i.e. it is an ARMA(2,2) with some additional regressors X and M.
[Z_t's are the white noise variables]
So, I run the following code:
for (i in 1:rep) { index=sample(4,15,replace=T)
final<-do.call(rbind,lapply(index,function(i)
2013 Jun 28
1
OT: About rebuilding RHS and RHEV
HI all,
Somebody had tried to do a rebuild of RedHat Storage Server 2.0 and
RHEV 3.2 hypervisor with CentOS? Mock is an option to accomplish this?
Thanks.
2012 Jan 14
0
[LLVMdev] TableGen: Avoid/Ignore the "no immediates on RHS of commutative node" constraint.
Dear all,
I was wondering if it is possible in TableGen to either:
1. Selectively define an instruction depending on an SDNode's properties,
e.g. if the SDNode is not commutative.
2. Override/ignore the TableGen error given when a commutative node has an
immediate on the LHS.
My case comes from trying to define a generic ALU operation multiclass for
my target, which includes a
2001 Nov 15
0
rhs of == does not work with a list of items. should it ? (PR#1173)
Paul.White@dsto.defence.gov.au wrote:
>
> > Hello bug people,
> >
> > Version:
> > platform = i686-pc-linux-gnu
> > arch = i686
> > os = linux-gnu
> > system = i686, linux-gnu
> > status =
> > major = 1
> > minor = 3.1
> > year = 2001
> > month = 08
> > day = 31
> > language = R
> >
> >