similar to: tests for measures of influence in regression

Displaying 20 results from an estimated 700 matches similar to: "tests for measures of influence in regression"

1999 Jun 23
1
Influence.measures
I am using rw0641 with Windows 98. To list just the influential repetitiones that result from "influence.measures", I am using the input result <- lm(y~x) and the code from the example in the help for "influence.measures" INFLM <- function(result){ inflm <- influence.measures(result) which(apply(inflm$is.inf,1,any)) } It works fine up to now with the
2008 Mar 09
1
Formula for whether hat value is influential?
I was wondering if someone might be able to tell me what formula R's influence.measures function uses for determining whether the hat value it computes is influential (i.e., the true/false value in the "hat" column of the returned is.inf data frame). The reason I'm asking is that its results disagree with what I've just learned in my statistics class, namely that a point
2005 Jun 27
1
delta-beta's
Hi there I have created a multivariate logistic regression model looking at the presence/absence of disease on farms. I would like to plot the diagnostic plots recommended by Hosmer & Lemeshow to look particularly for any points of high influence. In order to do this I need to extract values for delta-beta. The function dfbeta gives a value for change in each coefficient but I am looking
2012 Feb 15
1
influence.measures()
Hi dear all, I'm wondering about the question that; Does the influence.measures(model) for linear models valid for general linear models such as logistic regression models? That is; If I fit the model like model <- glm( y~X1+X2, family=binomial) Then, if i apply the function "influence.measures(model), i will get the result of influence measures. These result are valid for
2003 Jun 12
1
What PRECISELY is the dfbetas() or lm.influence()$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
2011 Feb 14
1
conditional value assignment
Dear R-Help, I am trying to compute a new variable, let's call it "target cannon orientation (tco)" based conditionally on old variables, "TargetColor," "CannonOriB," and "CannonOriR." For every case in the data set, if TargetColor is "B" then I want tco to equal the value for that case of CannonOirB, else CannonOriR. I've tried writing
2011 Apr 10
2
list to data frame
I need to make a data frame out of the data that I currently have in a list. This works, but is ugly: ineffData<-rbind(ineffFilesList[[1]], ineffFilesList[[2]], ineffFilesList[[3]], ineffFilesList[[4]], ineffFilesList[[5]], ineffFilesList[[6]], ineffFilesList[[7]], ineffFilesList[[8]], ineffFilesList[[9]], ineffFilesList[[10]], ineffFilesList[[11]], ineffFilesList[[12]], ineffFilesList[[13]],
2006 Aug 31
1
NaN when using dffits, stemming from lm.influence call
Hi all I'm getting a NaN returned on using dffits, as explained below. To me, there seems no obvious (or non-obvious reason for that matter) reason why a NaN appears. Before I start digging further, can anyone see why dffits might be failing? Is there a problem with the data? Consider: # Load data dep <-
2005 Sep 13
4
plot(<lm>): new behavior in R-2.2.0 alpha
As some of you R-devel readers may know, the plot() method for "lm" objects is based in large parts on contributions by John Maindonald, subsequently "massaged" by me and other R-core members. In the statistics litterature on applied regression, people have had diverse oppinions on what (and how many!) plots should be used for goodness-of-fit / residual diagnostics, and to my
2010 Aug 03
4
REmove level with zero observations
If I have a column with 2 levels, but one level has no remaining observations. Can I remove the level? Had intended to do it as listed below, but soon realized that even though there are no observations, the level is still there. For instance summary(dbs3.train.sans.influential.obs$HAC) yields 0 ,1 4685,0 nlevels(dbs3.train.sans.influential.obs$HAC) yields [1] 2 drop.list <- NULL
2011 Apr 07
2
replace an expression with its value, or read macros
I know my subject line seems odd, but I want to replace an expression—such as a variable—with its value. For example, I want to paste() some strings together, assign the result to a variable s, then use the value of s as a variable to hold another value. Something like this: import_subjects <- function (start, iterations) { for (i in 1:iterations) { # iterate from start to end s <-
2010 Mar 06
1
transposing data
Hi. I have repeated measures data of the form where each observation is a trial, and trials are grouped by subject, and variables encode whatever level of a factor was present during that trial, and the dependent variable is response time (RT). I want to transpose the data to a form suitable for MANOVA such that there is one observation per subject and RT is recoded across many
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,
2004 Mar 23
1
influence.measures, cooks.distance, and glm
Dear list, I've noticed that influence.measures and cooks.distance gives different results for non-gaussian GLMs. For example, using R-1.9.0 alpha (2003-03-17) under Windows: > ## Dobson (1990) Page 93: Randomized Controlled Trial : > counts <- c(18,17,15,20,10,20,25,13,12) > outcome <- gl(3,1,9) > treatment <- gl(3,3) > glm.D93 <- glm(counts ~ outcome +
2003 Nov 23
3
make check reg-tests-3
Should I submit this as a bug report? --- reg-tests-3.Rout.save Thu Jul 3 09:55:40 2003 +++ reg-tests-3.Rout Sun Nov 23 13:10:57 2003 @@ -1,17 +1,18 @@ -R : Copyright 2003, The R Development Core Team -Version 1.8.0 Under development (unstable) (2003-07-03) +R : Copyright 2003, The R Foundation for Statistical Computing +Version 1.8.1 (2003-11-21), ISBN 3-900051-00-3 R is free software and
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 [[alternative HTML version deleted]]
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,
2016 Jul 27
3
[RFC] One or many git repositories?
On 7/27/2016 12:17 PM, Chris Bieneman wrote: > > This is a really bad argument for large influential changes like this. Quite the contrary---anybody can participate and anybody can express their concerns, explain their goals, their workflow, etc. For a large influential changes like this, "zoning out" is a poor choice of action. > I suspect this is why the idea of having a