Displaying 20 results from an estimated 1100 matches similar to: "dfbetas without intercept"
2011 Apr 29
1
logistic regression with glm: cooks distance and dfbetas are different compared to SPSS output
Hi there,
I have the problem, that I'm not able to reproduce the SPSS residual
statistics (dfbeta and cook's distance) with a simple binary logistic
regression model obtained in R via the glm-function.
I tried the following:
fit <- glm(y ~ x1 + x2 + x3, data, family=binomial)
cooks.distance(fit)
dfbetas(fit)
When i compare the returned values with the values that I get in SPSS,
2009 Nov 13
1
dfbetas vs dfbeta
Hi, I've looked around but can't find a clear answer to the difference for
these two? Any help?
Thanks!
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2003 Jun 12
1
What PRECISELY is the dfbetas() or lm.influence()$coef ?
Hello. I want to get the proper influence function for the glm
coefficients in R. This is supposed to be inv(information)*(y-yhat)*x. So
I am wondering what is the exact mathematical formula for the output that
the functions:
dfbeta() OR lm.influence()$coefficients
return for a glm model. I am confused because:
1. Their columns don't sum to zero as influences should.
2. They
2009 Feb 19
1
matrix computation???
Hello
Can anyone tell me what I am doing wrong below? My Y and y_hat are the same.
A<-scale(stackloss)
n1<- dim(A)[1];n2<-dim(A)[2]
X<-svd(A)
Y<- matrix(A[,"stack.loss"],nrow=n1)
Y
y_hat <-matrix((X$u%*% t(X$u))%*%Y,nrow=n1,byrow=T)
y_hat
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2009 Apr 02
1
matrix vectorization or something else??
Hello
This may have been answered elsewhere, and I have looked on the web, but nothing helps. I am trying to do the following:
X<-matrix(c(1:15),nrow=3,byrow=T)
Y<-matrix(c(2,4,6,8,10),ncol=1)
I need to sum the product of each row of X by the remaining j rows multiplied by j y values (i.e sum( t(x_i) x_j y_j) )
Hope this makes sense.
Thanks in advance.
Ps: how do I reference all
2003 Jul 12
1
Problem with library "car"
I am using the Unix version of R (version 1.7.0), installed via fink on a G4
Macintosh. I recently upgraded from version 1.6.0 and found that the "car"
library now has a problem:
---Begin transcript---
>library(car)
Attaching package 'car':
The following object(s) are masked from package:base :
dfbeta dfbeta.lm dfbetas dfbetas.lm hatvalues hatvalues.lm
2001 Apr 28
9
two new packages
I've prepared preliminary versions of two packages that I plan eventually
to contribute to CRAN:
car (for "Companion to Applied Regression") is a package that provides a
variety of functions in support of linear and generalized linear models,
including regression diagnostics (e.g., studentized residuals, hat-values,
Cook's distances, dfbeta, dfbetas, added-variable plots,
2001 Apr 28
9
two new packages
I've prepared preliminary versions of two packages that I plan eventually
to contribute to CRAN:
car (for "Companion to Applied Regression") is a package that provides a
variety of functions in support of linear and generalized linear models,
including regression diagnostics (e.g., studentized residuals, hat-values,
Cook's distances, dfbeta, dfbetas, added-variable plots,
2001 Apr 28
9
two new packages
I've prepared preliminary versions of two packages that I plan eventually
to contribute to CRAN:
car (for "Companion to Applied Regression") is a package that provides a
variety of functions in support of linear and generalized linear models,
including regression diagnostics (e.g., studentized residuals, hat-values,
Cook's distances, dfbeta, dfbetas, added-variable plots,
2013 May 01
1
Trouble with methods() after loading gdata package.
Greetings to r-help land.
I've run into some program crashes and I've traced them back to methods()
behavior
after the package gdata is loaded. I provide now a minimal re-producible
example. This seems bugish to me. How about you?
dat <- data.frame(x = rnorm(100), y = rnorm(100))
lm1 <- lm(y ~ x, data = dat)
methods(class = "lm")
## OK so far
library(gdata)
2008 May 07
1
coxph - weights- robust SE
Hi,
I am using coxph with weights to represent sampling fraction of subjects.
Our simulation results show that the robust SE of beta systematically
under-estimate the empirical SD of beta.
Does anyone know how the robust SE are estimated in coxph using weights?
Is there any analytical formula for the “weighted” robust SE?
Any help is appreciated!
Thanks so much in advance
Willy
1999 Oct 21
1
left.solve
I have sort of an emergency question for the list. One of my professors
for an S-Plus intensive class distributed a function to produce partial
regression plots. I need to run it under R, because I'm doing the
homework on my home computer with a modem; hence I don't have the speed
required to emulate X-Windows and run S Plus off one of the campus
servers. Bottom line: I'm using R.
2010 Feb 21
1
tests for measures of influence in regression
influence.measures gives several measures of influence for each
observation (Cook's Distance, etc) and actually flags observations
that it determines are influential by any of the measures. Looks
good! But how does it discriminate between the influential and non-
influential observations by each of the measures? Like does it do a
Bonferroni-corrected t on the residuals identified by
2017 Apr 04
0
Some "lm" methods give wrong results when applied to "mlm" objects
I had a look at some influence measures, and it seems to me that currently several methods handle multiple lm (mlm) objects wrongly in R. In some cases there are separate "mlm" methods, but usually "mlm" objects are handled by the same methods as univariate "lm" methods, and in some cases this fails.
There are two general patterns of problems in influence measures:
2016 Apr 26
0
survival::clogit, how to extract residuals for GOF assessment
Hi Folks,
Hopefully this question has enough R and not too much stats to be
appropriate for this list. Based on,* Hosmer et al. 2013. Logistic
regression for matched case-control studies. Applied Logistic
Regression *(eqtn.
7.8)*, *I am assessing GOF of conditional (or matched) logistic regression
models with the *standardized Pearson residuals*. The authors define
?large? as delta chi-squared
2009 Oct 10
2
easy way to find all extractor functions and the datatypes of what they return
Am I asking for too much:
for any object that a stat proc returns ( y <- lm( y~x) , etc ) ) , is there
a super convenient function like give_all_extractors( y ) that lists all
extractor functions , the datatype returned , and a text descriptor
field ("pairwisepval" "lsmean" etc)
That would just be so convenient.
What are my options for querying an object so that I can
2010 Mar 26
0
row names in regression results and saving the identification results from added variable plots
Hello all,
Is there a way to take the row names from my data.frame and have them
imported to the regression results?
At the moment, I my original data frame looks like this:
/ Riding name / Turnout / Margin / Expenditures
1 / Abbotsford
2 / .
3 / .
4 / .Willow
I know how to set the row names for the original data frame to be the
Riding name, but when I run the regression, the residuals,
2002 Apr 19
4
Durbin-Watson test in packages "car" and "lmtest"
Hi,
P-values in Durbin-Watson test obtained through the use of functions available in packages "lmtest" and "car" are different. The difference is quite significant. function "dwtest" in "lmtest" is much faster than "burbinwatson" in "car". Actually, you can take a nap while the latter trying to calculated Durbin-Watson test. My question
2010 Oct 06
2
A problem --thank you
dear:teacher
i have a problem which about the polr()(package "MASS"), if the response must have 3 or more levels?
and how to fit the polr() to 2 levels?
thank you.
turly yours
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2005 Jun 27
1
delta-beta's
Hi there
I have created a multivariate logistic regression model looking at the
presence/absence of disease on farms. I would like to plot the diagnostic
plots recommended by Hosmer & Lemeshow to look particularly for any points of
high influence. In order to do this I need to extract values for delta-beta.
The function dfbeta gives a value for change in each coefficient but I am
looking