Displaying 20 results from an estimated 1000 matches similar to: "coefficient of partial determination...partial r square [ redux]"
2007 Aug 20
1
Ask for functions to obtain partial R-square (squared partial correlation coefficients)
The partial R-square (or coefficient of partial determination, or
squared partial correlation coefficients) measures the marginal
contribution of one explanatory variable when all others are already
included in multiple linear regression model.
The following link has very clear explanations on partial and
semi-partial correlation:
http://www.psy.jhu.edu/~ashelton/courses/stats315/week2.pdf
In
2007 Jul 12
1
p-value from survreg
The question was how to get the p-value from the fit below, as an S object
sr<-survreg(s~groups, dist="gaussian")
Coefficients:
(Intercept) groups
-0.02138485 0.03868351
Scale= 0.01789372
Loglik(model)= 31.1 Loglik(intercept only)= 25.4
Chisq= 11.39 on 1 degrees of freedom, p= 0.00074
n= 16
----
In general, good places to start are
> names(sr)
>
2001 Oct 16
4
two way ANOVA with unequal sample sizes
Hi,
I am trying a two way anova with unequal sample sizes but results are not
as expected:
I take the example from Applied Linear Statistical Models (Neter et al.
pp889-897, 1996)
growth rate gender bone development
1.4 1 1
2.4 1 1
2.2 1 1
2.4 1 2
2.1 2 1
1.7 2 1
2.5 2 2
1.8 2 2
2 2 2
0.7 3 1
1.1 3 1
0.5 3 2
0.9 3 2
1.3 3 2
expected results are
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
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)
2011 Apr 08
3
xyplot, groups and colors
Dear ExpeRts,
I am trying to plot a bunch of growth curves and would like to get
some more control over groups and line colors than I seem to have.
Example:
# make some data
dat <- Orange
dat$group <- ifelse(dat$Tree%in%c('1','4','5'), 'A', 'B')
# plot
xyplot(circumference~age, dat, groups=group)
# now use lines to make the growth curve more
2011 Mar 05
2
Grouping data in ranges in table
Working with the built in R data set Orange, e.g. with(Orange, table(age,
circumference)).
How should I go about about grouping the ages and circumferences in the
following ranges and having them display as such in a table?
age range:
118 - 664
1004 - 1372
1582
circumference range:
30-58
62- 115
120-142
145-177
179-214
Thanks for any feedback and insights, as I hoping for an output that
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=
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
2006 May 17
1
nlme model specification
Hi folks,
I am tearing my hair out on this one.
I am using an example from Pinheiro and Bates.
### this works
data(Orange)
mod.lis <- nlsList(circumference ~ SSlogis(age, Asymp, xmid, scal),
data=Orange )
### This works
mod <- nlme(circumference ~ SSlogis(age, Asymp, xmid, scal),
data=Orange,
fixed = Asymp + xmid + scal ~ 1,
start =
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
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,
2010 Feb 27
1
Newbie help with ANOVA and lm.
Would someone be so kind as to explain in English what the ANOVA code (anova.lm) is doing? I am having a hard time reconciling what the text books have as a brute force regression and the formula algorithm in 'R'. Specifically I see:
p <- object$rank
if (p > 0L) {
p1 <- 1L:p
comp <- object$effects[p1]
asgn <-
2008 Sep 27
1
seg.fault from nlme::gnls() {was "[R-sig-ME] GNLS Crash"}
>>>>> "VW" == Viechtbauer Wolfgang (STAT) <Wolfgang.Viechtbauer at STAT.unimaas.nl>
>>>>> on Fri, 26 Sep 2008 18:00:19 +0200 writes:
VW> Hi all, I'm trying to fit a marginal (longitudinal)
VW> model with an exponential serial correlation function to
VW> the Orange tree data set. However, R crashes frequently
VW>
2010 Aug 30
2
while loop until end of file
Hi Guys,
stumped by a simple problem. I would like to take a file of the form
Pair group param1
1 D 10
1 D 10
1 R 10
1 D 10
2 D 10
2 D 10
2 D 10
2 R 10
2 R 10
etc..
and for each pair, calculate the average of
2007 May 17
4
R2 always increases as variables are added?
Hi, everybody,
3 questions about R-square:
---------(1)----------- Does R2 always increase as variables are added?
---------(2)----------- Does R2 always greater than 1?
---------(3)----------- How is R2 in summary(lm(y~x-1))$r.squared
calculated? It is different from (r.square=sum((y.hat-mean
(y))^2)/sum((y-mean(y))^2))
I will illustrate these problems by the following codes:
2004 Jan 12
2
Re: Nauti miles
>
>
I might as well add to the offtopic thread... why are natuical miles longer
than "regular" miles?
Andrew
A nautical mile is 1 minute of latitude.
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2008 Mar 25
1
Combining several mappings in ggplot2
Hello,
I want to be able to make a plot that has several series with
different color and linetype.
Online documentation suggest that this is possible, but I haven't found how:
"We can also create redundant mappings, mapping the same variable to
multiple aesthetics. This is most useful when producing a graphic for
both colour and black and white display."
Here's what I have to
2007 Jun 18
1
how to obtain the OR and 95%CI with 1 SD change of a continue variable
Dear all,
How to obtain the odds ratio (OR) and 95% confidence interval (CI) with
1 standard deviation (SD) change of a continuous variable in logistic
regression?
for example, to investigate the risk of obesity for stroke. I choose the
happening of stroke (positive) as the dependent variable, and waist
circumference as an independent variable. Then I wanna to obtain the OR
and 95% CI with
2023 Nov 03
1
I need to create new variables based on two numeric variables and one dichotomize conditional category variables.
Hello Everyone,
I have three variables: Waist circumference (WC), serum triglyceride (TG)
level and gender. Waist circumference and serum triglyceride is numeric and
gender (male and female) is categorical. From these three variables, I want
to calculate the "Lipid Accumulation Product (LAP) Index". The equation to
calculate LAP is different for male and females. I am giving both