Displaying 20 results from an estimated 10000 matches similar to: "Fixing the coefficient of a regressor in formula"
2006 Jul 05
2
Colinearity Function in R
Is there a colinearty function implemented in R? I
have tried help.search("colinearity") and
help.search("collinearity") and have searched for
"colinearity" and "collinearity" on
http://www.rpad.org/Rpad/Rpad-refcard.pdf but with no
success.
Many thanks in advance,
Peter Lauren.
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,
2006 Oct 24
2
colinearity?
I'm sorry to all those who are tired of seeing my email appear in need of
help. But, I've never coded in any program before, so this has been a
difficult process for me.
Is there a simple function to test for colinearity in R? I'm running a
logistic regression and a linear regression.
Thanks for the help!
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2004 Jun 30
1
linear models and colinear variables...
Hi!
I'm having some issues on both conceptual and
technical levels for selecting the right combination
of variables for this model I'm working on. The basic,
all inclusive form looks like
lm(mic ~ B * D * S * U * V * ICU)
Where mic, U, V, and ICU are numeric values and B D
and S are factors with about 16, 16 and 2 levels
respectively. In short, there's a ton of actual
explanatory
2012 Nov 06
2
R and SPSS
Hi group:
I have a data set, which has severe colinearity problem. While running linear regression in R and SPSS, I got different models. I am wondering if somebody knows how to make the two software output the same results. (I guess the way R and SPSS handling singularity is different, which leads to different models.)
Thanks.
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2024 Apr 23
1
System GMM yields identical results for any weighting matrix
A copy of this question can be found on Cross Validated:
https://stats.stackexchange.com/questions/645362
I am estimating a system of seemingly unrelated regressions (SUR) in R.
Each of the equations has one unique regressor and one common regressor. I
am using `gmm::sysGmm` and am experimenting with different weighting
matrices. I get the same results (point estimates, standard errors and
2024 Apr 23
1
System GMM yields identical results for any weighting matrix
Generally speaking, this sort of detailed statistical question about a
speccial package in R does not get a reply on this general R
programming help list. Instead, I suggest you either email the
maintainer (found by ?maintainer) or ask a question on a relevant R
task view, such as
https://cran.r-project.org/web/views/Econometrics.html . (or any other
that you judge to be more appropriate).
2005 May 01
1
Partial F-test comparing full and reduced regression models
Dear all:
I have a regression model that has collinearity problems (between three
regressor variables). I need a F-test that will allow me to compare
between full (with all variables) and partial models (minus 1=<
variables). The general F-test formula I'm using is:
F = {[SS(full model) - SS(reduced model)] / (#variables taken out)} /
MSS(full model)
Unfortunately, the ANOVA table
2009 Mar 12
2
MANOVA
Hi All,
I have questions about MANOVA which I am still not sure if appropriately I should use it.
For example I have a data set like this:
BloodPressure (BP) Weight Height
120 115 165
125 145 198
156 99 176
I know that BloodPressure is correlated with both Weight and Height, however colinearity exists between Weight and Height. When I use BP = Weight + Height
2008 Jul 23
1
Time series reliability questions
Hello all,
I have been using R's time series capabilities to perform analysis for quite
some time now and I am having some questions regarding its reliability. In
several cases I have had substantial disagreement between R and other packages
(such as gretl and the commercial EViews package).
I have just encountered another problem and thought I'd post it to the list. In
this case,
2017 Mar 10
2
named arguments in formula and terms
Hi, we came across the following unexpected (for us) behavior in
terms.formula: When determining whether a term is duplicated, only the
order of the arguments in function calls seems to be checked but not their
names. Thus the terms f(x, a = z) and f(x, b = z) are deemed to be
duplicated and one of the terms is thus dropped.
R> attr(terms(y ~ f(x, a = z) + f(x, b = z)),
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,
2006 Feb 24
3
Sorting alphanumerically
I'm trying to sort a DATAFRAME by a column "ID" that contains
alphanumeric data. Specifically,"ID" contains integers all preceeded
by the character "g" as in:
g1, g6, g3, g19, g100, g2, g39
I am using the following code:
DATAFRAME=DATAFRAME[order(DATAFRAME1$ID),]
and was hoping it would sort the dataframe by ID in the following manner
g1, g2, g3, g6, g19,
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
2003 Sep 01
1
Arima with an external regressor
Hello,
Does anybody know if the function arima with an external regressor (xreg)
applies the auto correlation on the dependant variable or on the residuals.
In comparison with SAS (proc autoreg), it seems that the auto correlation
applies on the residuals but i'd like to have the confirmation.
I want to estimate:
Y[t] = a[1]*X[t] + a[2] + E[t]
with E[t]=b[1]*E[t-1]
Should I use :
arima(Y,
2017 May 15
2
Datos atómicos
Carlos:
Te agradezco mucho tu rápida respuesta y mucho me apena haber planteado tan
mal el problema. Porque la matriz en realidad es:
g1 g2 g3 g4 g5 g6 g7
g1 0 18 13 16 11 12 15
g2 18 0 25 13 22 16 10
g3 13 25 0 28 23 13 25
g4 16 13 28 0 6 7 3
g5 11 22 23 6 0 18 17
g6 12 16 13 7 18 0 8
g7 15 10 25 3 17 8 0
Entonces cada cantidad debe conservar la pertenencia al grupo
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)
2009 May 27
1
How to write a loop?
Dear R helpers,
Following is a R script I am using to run the Fast Fourier Transform. The csv files has 10 columns with titles m1, m2, m3 .....m10.
When I use the following commands, I am getting the required results. The probelm is if there are 100 columns, it is not wise to define 100 commands as fk <- ONS$mk and so on. Thus, I need some guidance to write the loop for the STEP A and
2017 May 05
1
lm() gives different results to lm.ridge() and SPSS
Hi John,
Thanks for the comment... but that appears to mean that SPSS has a big problem. I have always been told that to include an interaction term in a regression, the only way is to do the multiplication by hand. But then it seems to be impossible to stop SPSS from re-standardizing the variable that corresponds to the interaction term. Am I missing something? Is there a way to perform the
2007 Apr 01
3
Doing partial-f test for stepwise regression
Hello all,
I am trying to figure out an optimal linear model by using stepwise
regression which requires partial f-test, I did some Googling on the
Internet and realised that someone seemed to ask the question before:
Jim Milks <jrclmilks at joimail.com> writes:
> Dear all:
>
> I have a regression model that has collinearity problems (between
> three regressor variables). I