Displaying 20 results from an estimated 100 matches similar to: "interpretation of lm"
2013 Jan 17
3
Colors in interaction plots
Hi,
I am trying to plot an interaction.plot with different color for each
level of a factor. It has an erratic behavior.
For example, it works for the first interaction.plot below, with the
example from the ALDA book, but not with the other plots, from the NPK
dataset:
# from http://www.ats.ucla.edu/stat/r/examples/alda/ch2.htm
tolerance <-
2005 May 20
1
Problem with proj
Hi all,
Perhaps this in an inappropriate post, but I've found a bug in proj
I'd like to track down a bit further before making a formal bug report.
The example below shows the problem, if you change the rownames proj
fails. The problem seems to be that there is a mismatch in the rownames
in the qr objects constructed by aov and the rownames that proj is
expecting them to have.
2010 Apr 21
1
How to obtain the coefficients from a summary of aov ?
Dear Madame, Dear Sir,
I am able to obtain the coefficients from a 'summary' of 'lm', but NOT from a 'summary' of 'aov'.
The following example shows my steps.
## Initialize
rm(list = ls()) # remove (almost) everything in the working environment
utils::data(npk, package="MASS") # get data
model <- yield ~ block + N*P*K
## Using lm
npk.lm <-
2003 Jan 24
1
model.tables and NA?
Hi,
This might be a minor bug, or it could be that I'm just mis-using the tools
(again).
If you modify the example for model.tables to introduce an NA,
N <- c(0,1,0,1,1,1,0,0,0,1,1,0,1,1,0,0,1,0,1,0,1,1,0,0)
P <- c(1,1,0,0,0,1,0,1,1,1,0,0,0,1,0,1,1,0,0,1,0,1,1,0)
K <- c(1,0,0,1,0,1,1,0,0,1,0,1,0,1,1,0,0,0,1,1,1,0,1,0)
yield <-
2003 Apr 17
2
make check failure with R-1.7.0
I'm baffled. When I run make check after installing from source, I
get a Error 2. From my understanding of how these things work, it
would appear to be coming from this (as at the end of base-Ex.Rout.fail:
> has.VR <- require(MASS, quietly = TRUE)
Attaching package 'MASS':
The following object(s) are masked from package:base :
confint confint.lm nclass.FD nclass.scott
2008 Nov 26
1
S4 slot containing either aov or NULL
Dear listmembers,
I would like to define a class with a slot that takes either an object
of class aov or NULL. I have been reading "S4 Classes in 15 pages more
or less" and "Lecture: S4 classes and methods"
#First I tried with list and NULL
setClass(listOrNULL")
setIs("list", "listOrNULL")
setIs("NULL", "listOrNULL")
#doesn't
2002 Aug 06
2
AOV in MASS not the same??
I would appreciate it if someone could explain the results of the
example from the aov() help file. The output given below is different
from book
Venables and Ripley - MASS
The results In R1.5.1 (Under windows) is as follows:
> N <- c(0,1,0,1,1,1,0,0,0,1,1,0,1,1,0,0,1,0,1,0,1,1,0,0)
> P <- c(1,1,0,0,0,1,0,1,1,1,0,0,0,1,0,1,1,0,0,1,0,1,1,0)
> K <-
2017 Nov 29
1
2^3 confounded factorial experiment
The following R commands were written:
>help.search("factorial")
>data(npk)
>npk
>coef(npk.aov)
In the output of coef command, please explain me the interpretation of coefficients of block1 to block 6 in this 2^3 confounded factorial experiment.
Thanks.
[[alternative HTML version deleted]]
2010 Jul 23
1
model.tables call fails with "Error in inherits(object, "formula")"
Hello,
I noticed that model.tables fails when applied to an aov() fit if called
inside a function. The problem seems to occur when as.formula is used
inside a function on a string containing
"<formula> + Error( x / y )"
The reason I tried to use as.formula is to generate dynamic calls to aov().
Here is a minimal example illustrating the problem:
## Example
test <-
2008 Feb 17
0
difference between lme and lmer in df calculation
Hello all. I'm currently working with mixed models, and have noticed
a curious difference between the nlme and lmer packages. While I
realize that model selection with mixed models is a tricky issue, the
two packages currently produce different AIC scores for the same
model, but they systematically differ by 2. In looking at the logLik
values for each method, I find that they
2004 Aug 25
0
S3 classes in S4 class definitions
One of the changes some packages are noticing from the recent
modifications to methods is warnings of "undefined classes" during
installation when the package extends S3 classes or uses them as slots
UNLESSS they have been declared in a setOldClass() call. The green book
"strongly recommends" declaring S3 classs this way (pp 449-451).
The warnings on undeclared classes
2003 Jun 26
1
Correct contrast for unreplicated 2K factorial design
Hi all,
I have been trying to reproduce an analysis from Douglas Montgomery?s
book on design and analysis of experiments. Table 6.10 of example 6.2 on
page 246, gives a table as follows:
> NPK <- expand.grid(A=mp,B=mp,C=mp,D=mp)
> Rate <- c(45,71,48,65,68,60,80,65,43,100,45,104,75,86,70,96)
> filtration <- cbind(NPK,Rate)
> filtration
A B C D Rate
1 - - - - 45
2
2003 Feb 13
2
ROC
Hi, can you advise me is there any ROC(Receiver
Operating Characteristic)analysis program in R?
Thanks,
Dechao
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2002 Mar 07
8
linear correlation?
Whether the two variables have the same units does not matter. Moreover,
even if there were some way of converting cm to kg the correlation would
still be the same because the correlation is invariant under unit conversion
as it is invariant under multiplication of its arguments by a constant.
As for your second question, the correlation estimator is a continuous
function of each of the
1999 Sep 15
0
buglet in lm.influence() -- easy fix but... (PR#278)
(R 0.65.0 and earlier):
example(aov)
lm.influence(npk.aov)
gives
Error: NA/NaN/Inf in foreign function call (arg 6)
which comes from the lm.obj$coefficients
(the last 3-way interaction coefficient is indetermined and accordingly NA)
argument passed to .Fortran("lminfl",...) inside lm.influence.
The following is a simple correct patch
--- lm.influence.R 1999/08/13
2005 May 30
3
sapply following using by with a list of factors
Background:
OS: Linux Mandrake 10.1
release: R 2.0.0
editor: GNU Emacs 21.3.2
front-end: ESS 5.2.3
---------------------------------
Colleagues
I am having some trouble extracting results from the function by, used to
average variables in a data.frame first by one factor (depth) and then by a
second factor (station). The real data.frame is quite large
> dim(data.2001)
[1] 32049 11
Here is a
2003 Apr 09
1
'Apparently' trouble with name spaces and Sweave...
Ben Bolstad experienced something odd while running R CMD check over
a package of ours using r-devel (yesterday's fresh).
He tracked down the problem to a vignette calling 'library(MASS)'.
Please kindly ignore if this is a known (and temporary) issue.
Laurent
----- Forwarded message from Ben Bolstad <bolstad@stat.berkeley.edu> -----
Return-Path:
2007 Jan 15
2
model simplification in repeated anova
Hi, I've done a repeated ANOVA looking as follows:
model<-aov(y~a*b*c+Error(d))
Now I want to get rid of some or all of the interactions. But neither
AIC nor anova work. What is the appropriate function to test my model?
1999 Nov 30
3
model.tables
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2009 Feb 18
2
[package-car:Anova] extracting residuals from Anova for Type II/III Repeated Measures ?
Hello dear R members.
I have been learning the Anova syntax in order to perform an SS type III
Anova with repeated measures designs (thank you Prof. John Fox!)
And another question came up: where/what are the (between/within) residuals
for my model?
############ Play code:
phase <- factor(rep(c("pretest", "posttest", "followup"), c(5, 5, 5)),