Displaying 18 results from an estimated 18 matches similar to: "where did the factor name go"
2010 Apr 12
2
Interpreting factor*numeric interaction coefficients
Dear all,
I am a relative novice with R, so please forgive any terrible errors...
I am working with a GLM that describes a response variable as a function of
a categorical variable with three levels and a continuous variable. These
two predictor variables are believed to interact.
An example of such a model follows at the bottom of this message, but here
is a section of its summary table:
2011 Nov 15
3
Question about linear regression in R
Hi all,
I wrote a r program as below:
x <- 1:10
y <- c(3,3,3,3,3,3,3,3,3,3)
fit <- lm(log(y) ~ x)
summary(fit)
And I expect to get some error message from R, because "y" is constant.
But, I got the message as below:
> summary(fit)
Call:
lm(formula = log(y) ~ x)
Residuals:
Min 1Q Median 3Q Max
-6.802e-17 -3.933e-17 -1.063e-17 1.807e-17
2006 Jun 21
1
Extract information from the summary of 'lm'
Hi Everyone,
I just don't know how to extract the information I
want from the summary of a linear regression model
fitting.
For example, I fit the following simple linear
regression model:
results = lm(y_var ~ x_var)
summary(results) gives me:
Call:
lm(formula = y_var ~ x_var)
Residuals:
Min 1Q Median 3Q Max
-5.9859 -1.5849 0.4574 2.0163 4.6015
Coefficients:
2012 Feb 03
1
ordering of factor levels in regression changes result
I was surprised to find that just changing the base level of a factor variable changed the number of significant coefficients in the solution.
I was surprised at this and want to know how I should choose the order of the factors, if the order affects the result.
Here is the small example. It is taken from 'The R Book', Crawley p. 365.
The data is at
2008 Oct 16
2
Saving results of Kruskal Walis test
Hello,
I am running Kruskal-Walis test in R. When I try to save results using
write.table it gives me the following error :
Error in as.data.frame.default(x[[i]], optional = TRUE, stringsAsFactors =
stringsAsFactors) :
cannot coerce class "htest" into a data.frame
The overall code is as follows :
>data_file = read.table("~/DATA.dir/data_file.txt", header=T)
2001 May 23
2
help: exponential fit?
Hi there,
I'm quite new to R (and statistics),
and I like it (both)!
But I'm a bit lost in all these packages,
so could someone please give me a hint
whether there exists a package for fitting
exponential curves (of the type
t --> \sum_i a_i \exp( - b_i t))
on a noisy signal?
In fact monoexponential decay + polynomial growth
is what I'd like to try.
Thanks in advance,
2003 Jan 22
3
Error when using polr() in MASS
Dear all,
I get an error message when I use polr() in MASS. These are my data:
skugg grupp frekv
4 1 gr3 0
5 2 gr3 3
6 3 gr3 6
10 1 gr5 1
11 2 gr5 12
12 3 gr5 1
>
> summary(polr(skugg ~ grupp, weights=frekv, data= skugg.cpy1.dat))
Error in optim(start, fmin, gmin, method = "BFGS", hessian = Hess, ...) :
2012 Dec 07
1
Help with manipulation of matrix object
Hi list,
I have a problem which I was stuck on for a while, and after many days
still cannot find a solution to.
I have a matrix, measuring m X n. An example matrix will be this:
>dput(sample)
structure(c(2315101, 2315102, 2315103, 2315104, 2315105, 2315107,
2315108, 2315110, 2315112, 2315114, 2315116, 2315118, 2315120,
2315122, 2315124, 2315126, 2315127, 2315128, 2315130, 2315131,
2315132,
2012 Jun 13
1
Tukey Kramer with ANOVA (glm)
Hello,
I am performing a BACI analysis with ANOVA using the following glm:
fit1<-glm(log(Cucs_m+1)~(BA*Otter)+BA+Otter+ID+Primary, data=b1)
The summary(aov(fit1)) shows significance in the interaction; however, now I
would like to determine what combinations of BA and Otter are significantly
different (each factor has two levels). ID and PRIMARY substrates are
categorical and included in
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)),
2012 May 30
0
anova.coxph for multiple events model
Hi,
I'm trying to do a multiple events model using coxph. I need to choose which
covariates stay in the final model and i'm using anova but it seems that it
doesn't work with robust variances as a error message appears when I try to
do it:
/PWPfit<-coxph(Surv(ini,fim,status)~Sexo+Transmissao+Regime+HAART+Drogas+Psi+
+ CD4+CV+Neo+IO+cluster(idPARTICIPANTE)+strata(Estrato),data=PWP)
2012 Mar 06
1
How to apply two parameter function in data frame
I know this is something simple that I cannot do because I do not yet "think"
in R.
I have a data frame has a variable participation (a factor), and several
other factors.
I want a chisq test (no contingency tables) for participation vs all of the
other factors.
In SPSS I would do:
CROSSTABS
/TABLES= (my other factors) BY participation
/FORMAT=NOTABLES
/STATISTICS=CHISQ
2012 Oct 26
0
combined output with zelig is not working!?!
Hi everyone,
I have carried out a multiple imputation in R using Amelia II and have
created 5 multiply imputed datasets. The purpose of my research is to fit a
Poisson Model to the data to estimate numbers of hospital admissions.
Now that I have 5 completed datasets and I have to pool all the 5 datasets
to get one combined output for a poisson model.
I have checked previous queries about
2011 Aug 31
1
Hmisc Latex Question: column headings and Major Column Headings not properly alligned
Dear R users:
When I create a table without Major Column headings, my *regular* column headings appear correct in the typeset latex file. The major row heading and row groups are as they should.
w <- latex(mytab,title="",file="tab/my.tex",ctable=TRUE,caption="Descriptive statistics by
2002 Nov 27
0
R genetics package now available
The "genetics" package for handling single-locus genetic data is now
available on CRAN in both source and Windows binary formats. The purpose of
this package is to make it easy to create and manipulate genetic
information, and to facility use of this information in statistical models.
The library includes classes and methods for creating, representing, and
manipulating genotypes
2002 Nov 27
0
R genetics package now available
The "genetics" package for handling single-locus genetic data is now
available on CRAN in both source and Windows binary formats. The purpose of
this package is to make it easy to create and manipulate genetic
information, and to facility use of this information in statistical models.
The library includes classes and methods for creating, representing, and
manipulating genotypes
2012 Nov 23
2
[LLVMdev] [cfe-dev] costing optimisations
On 23.11.2012, at 15:12, john skaller <skaller at users.sourceforge.net> wrote:
>
> On 23/11/2012, at 5:46 PM, Sean Silva wrote:
>
>> Adding LLVMdev, since this is intimately related to the optimization passes.
>>
>>> I think this is roughly because some function level optimisations are
>>> worse than O(N) in the number of instructions.
>>
2012 Jul 06
4
differences between survival models between STATA and R
Dear Community,
I have been using two types of survival programs to analyse a data set.
The first one is an R function called aftreg. The second one an STATA
function called streg.
Both of them include the same analyisis with a weibull distribution. Yet,
results are very different.
Shouldn't the results be the same?
Kind regards,
J
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