Displaying 20 results from an estimated 3000 matches similar to: "R2 always increases as variables are added?"
2007 May 21
4
How to compare linear models with intercept and those without intercept using minimizing adjs R^2 strategy
Dear R-list,
I apologize for my many emails but I think I know how to desctribe my
problem differently and more clearly.
My question is how to compare linear models with intercept and those without
intercept using maximizing adjusted R^2 strategy.
Now I do it like the following:
> library(leaps)
> n=20
> x=matrix(rnorm(n*3),ncol=3)
> b=c(1,2,0)
> intercept=1
>
2002 May 09
4
Rsquared in summary(lm)
Hello,
I'm doing some linear regression:
>lm<-lm(osas~alp,data)
>summary(lm)
However, the Rsquared in the output of summary() is not the same as the
"standard" Rsquared calculated by spreadsheets, and outlined in
statistical guidebooks, being SSR/SSTO. The output says "multiple
Rsquared", but it is no multiple regression...
What's the difference?
Thanks,
2012 Nov 16
2
R-Square in WLS
Hi,
I am fitting a weighted least square regression and trying to compute
SSE,SST and SSReg but I am not getting SST = SSReg + SSE and I dont know
what I am coding wrong. Can you help please?
xnam <-colnames(X) # colnames Design Matrix
fmla1 <- as.formula(paste("Y ~",paste(xnam, collapse=
2008 Nov 03
2
Calculating R2 for a unit slope regression
Does anyone know of a literature reference, or a piece of code that can help me calculate the amount of variation explained (R2 value), in a regression constrained to have a slope of 1 and an intercept of 0?
Thanks!
Sebastian
J. Sebastián Tello
Department of Biological Sciences
285 Life Sciences Building
Louisiana State University
Baton Rouge, LA, 70803
(225) 578-4284 (office and lab.)
2009 Jul 25
2
r2 question
Hi everyone,
I have a question about calculating r-squared in R. I have tried searching the archives and couldn't find what I was looking for - but apologies if there is somewhere I can find this...
I carried out a droughting experiment to test plant competition under limited water. I had:
- 7 different levels of watering treatment (1 -7 - from most watered to least watered/)
- 15
2002 May 11
2
Bug on Mac version of lm()?
Dear Mac users,
Hi, as you might have probably read the thread of
"[R] Rsquared in summary(lm)" on May 10, it seems that Mac version of
lm() seem to be working incorrectly.
I enclose the script to produce the result both for lm() and manual
calculation for a simple regression. Could you run the script and
report with the version of R, so I don't have to go through every
builds
2006 Jan 10
2
Obtaining the adjusted r-square given the regression coefficients
Hi people,
I want to obtain the adjusted r-square given a set of coefficients (without the intercept), and I don't know if there is a function that does it. Exist????????????????
I know that if you make a linear regression, you enter the dataset and have in "summary" the adjusted r-square. But this is calculated using the coefficients that R obtained,and I want other coefficients
2012 Jul 18
1
Regression Identity
Hi,
I see a lot of folks verify the regression identity SST = SSE + SSR
numerically, but I cannot seem to find a proof. I wonder if any folks on
this list could guide me to a mathematical proof of this fact.
Thanks.
David.
--
View this message in context: http://r.789695.n4.nabble.com/Regression-Identity-tp4636829.html
Sent from the R help mailing list archive at Nabble.com.
2012 Nov 13
1
About systemfit package
Dear friends,
I have written the following lines in R console wich already exist in pdf
file systemfit:
data( "GrunfeldGreene" )
library( "plm" )
GGPanel <- plm.data( GrunfeldGreene, c( "firm", "year" ) )
greeneSur <- systemfit( invest ~ value + capital, method = "SUR",
+ data = GGPanel )
greenSur
I have obtained the following incomplete
2007 May 12
0
There might be something wrong with cv.lm(DAAG)
Hi, everyone
When I was using cv.lm(DAAG) , I found there might be something wrong with
it. The problem is that we can't use it to deal with a linear model with
more than one predictor variable. But the usage documentation
hasn't informed us about this.
You can find it by excuting the following code:
xx=matrix(rnorm(20*3),ncol=3)
bb=c(1,2,0)
yy=xx%*%bb+rnorm(20,0,10)
2007 May 21
0
Is this a bug in cv.lm(DAAG) ?
Dear R-list,
I'm not sure what I've found about a function in DAAG package is a bug.
When I was using cv.lm(DAAG) , I found there might be something wrong with
it. The problem is that we can't use it to deal with a linear model with
more than one predictor variable. But the usage documentation
hasn't informed us about this.
The code illustrates my discovery:
> library(DAAG)
2013 May 16
2
R looping help
Hey I'm not really sure what I should put on here, but I am having trouble
with my R code. I am trying to get the p-values, R^2s etc for a number of
different groups of variables that are all in one dataset.
This is the code:
#Stand counter
st<-1
#Collections
stands<-numeric(67)
slopes<-numeric(67)
intercepts<-numeric(67)
mses<-numeric(67)
rsquares<-numeric(67)
2007 May 21
0
How to conduct a hypothesis test : Ho:|E(X)|=|E(Y)|<->H1:otherwise NOT R question
Dear R-list,
I am sorry for my shortage of stat knowlege. I want know how to conduct a
hypothesis test : Ho:|E(X)|=|E(Y)|<->H1:otherwise.
Actually, in my study, X and Y is two observations of bias,
where bias=u^hat-u, u is a parameter I concerned. Given X=(u^hat_xi - u) and
Y=(u^hat_yi - u), I want to know which bias is smaller, or the absolute
expection of which is smaller. Due to limit
2005 Mar 08
1
coefficient of partial determination...partial r square [ redux]
If I'm not mistaken, partial R-squared is the R^2 of the quantities plotted
in a partial residual plot, so you can base the computation on that. Prof.
Fox's `car' package on CRAN has a function for creating those plots, but you
need to figure out the way to extract the quantities being plotted.
[In any case, the basic tools for doing such computations are all in R, and
it
2010 May 11
5
Regressions with fixed-effect in R
Hi there,
Maybe people who know both R and econometrics will be able to answer
my questions.
I want to run panel regressions in R with fixed-effect. I know two
ways to do it.
First, I can include factor(grouping_variable) in my regression equation.
Second, I plan to subtract group mean from my variables and run OLS
panel regression with function lm().
I plan to do it with the second way because
2004 Jul 01
2
R can't find some functions in assist package
Oh yes. The "load package" under the "packages menu" in the Windows version
does that. To check I typed "library(assist)" after starting R. Same
behavior, ssr is found, but others like predict.ssr, and plot.ssr, give a
"not found" message.
Thanks for the suggestion.
Mike
2007 May 11
1
model seleciton by leave-one-out cross-validation
Hi, all
When I am using mle.cv(wle), I find a interesting problem: I can't do
leave-one-out cross-validation with mle.cv(wle). I will illustrate the
problem as following:
> xx=matrix(rnorm(20*3),ncol=3)
> bb=c(1,2,0)
> yy=xx%*%bb+rnorm(20,0,0.001)+0
> summary(mle.cv(yy~xx,split=nrow(xx)-1,monte.carlo=2*nrow(xx),verbose=T),
num.max=1)[[1]]
mle.cv: dimension of the split subsample
2010 May 19
4
[LLVMdev] Support for per-loop pragma
Hi Chris,
Thanks. I will see what I can do for this.
Junjie
On Wed, May 19, 2010 at 3:45 PM, Chris Lattner <clattner at apple.com> wrote:
>
> On May 19, 2010, at 2:38 PM, Junjie Gu wrote:
>
>> Many compilers support per-loop pragma, such as loop unrolling (ie
>> #pragma unroll=2). Is there any LLVM project/effort going on
>> in this area ? What is the expected
2006 Jun 16
2
Effect size in mixed models
Hello,
Is there a way to compare the relative relevance of fixed and random effects
in mixed models? I have in mind measures of effect size in ANOVAs, and would
like to obtain similar information with mixed models.
Are there information criteria that allow to compare the relevance of each
of the effects in a mixed model to the overall fit?
Thank you,
Bruno
2010 Jun 02
0
[LLVMdev] Support for per-loop pragma
I'd like to add a pragma support in llvm. I am thinking about using a
llvm intrinsic to represent each pragma, such as
llvm.pragma (metadata, ...)
where metadata describes a pragma. So if an application has:
#pragma p1 ..
#pragma p2...
for (...)
The llvm IR would be
llvm.pragma (metadata..) // for p1
llvm.pragma (metadata..) // for p2
llvm IR for "for