Displaying 20 results from an estimated 200 matches similar to: "Question about linear regression in R"
2010 Aug 12
3
Regression Error: Otherwise good variable causes singularity. Why?
This command
cdmoutcome<- glm(log(value)~factor(year)
> +log(gdppcpppconst)+log(gdppcpppconstAII)
> +log(co2eemisspc)+log(co2eemisspcAII)
> +log(dist)
> +fdiboth
> +odapartnertohost
> +corrupt
> +log(infraindex)
> +litrate
> +africa
>
2010 Jan 08
2
how to get perfect fit of lm if response is constant
Hello.
Consider the response-variable of data.frame df is constant, so analytically
perfect fit of a linear model is expected. Fitting a regression line using
lm result in residuals, slope and std.errors not exactly zero, which is
acceptable in some way, but errorneous. But if you use summary.lm it shows
inacceptable error propagation in the calculation of the t value and the
corresponding
2009 Feb 17
2
Chromatogram deconvolution and peak matching
Hi,
I'm trying to match peaks between chromatographic runs.
I'm able to match peaks when they are chromatographed with the same method,
but not when there are different methods are used and spectra comes in to
play.
While searching I found the ALS package which should be usefull for my
application, but I couldn't figure it out.
I made some dummy chroms with R, which mimic my actual
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:
2007 May 28
1
where did the factor name go
> tmp <- data.frame(y=rnorm(12), a=factor(rep(letters[1:4],3)))
> tmp
y a
1 -0.60866099 a
2 0.55500538 b
3 0.12231693 c
4 -0.24613790 d
5 -0.09253593 a
6 -1.54652581 b
7 0.17204210 c
8 -1.22778942 d
9 1.22151194 a
10 -0.43982577 b
11 -1.25444287 c
12 -0.97251060 d
> tmp.aov <- aov(y ~ a, data=tmp)
> summary(tmp.aov)
Df Sum Sq Mean Sq F value
2008 Jun 21
2
Generating groupings of ordered observations
Dear List,
I have a problem I'm finding it difficult to make headway with.
Say I have 6 ordered observations, and I want to find all combinations
of splitting these 6 ordered observations in g groups, where g = 1, ...,
6. Groups can only be formed by adjacent observations, so observations 1
and 4 can't be in a group on their own, only if 1,2,3&4 are all in the
group.
For example,
2017 Sep 05
4
Interesting behavior of lm() with small, problematic data sets
I've recently come across the following results reported from the lm() function when applied to a particular type of admittedly difficult data. When working with
small data sets (for instance 3 points) with the same response for different predicting variable, the resulting slope estimate is a reasonable approximation of the expected 0.0, but the p-value of that slope estimate is a surprising
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,
2008 Mar 25
1
Subset of matrix
Dear R users
I have a big matrix like
6021 1188 790 290 1174 1015 1990 6613 6288
100714
6021 1 0.658 0.688 0.474 0.262 0.163 0.137 0.32
0.252 0.206
1188 0.658 1 0.917 0.245 0.331 0.122 0.148 0.194
0.168 0.171
790 0.688 0.917 1 0.243 0.31 0.122 0.15 0.19
0.171 0.174
290 0.474
2017 Jul 30
1
Add Anova statistics in each figure
Hi R Users,
I created interaction plots in ggplot2 and was trying to add output of two way ANOVA models, especially only interaction ( example treatment*control F(XX, XX) = xxx, p = xxx) into figures, but i was not able to add. Would you mind to help on how I can add information into each figure? I have attached the example data and the code that I used for this.
dat<-structure(list(Sites
2009 Oct 26
1
explalinig the output of my linear model analysis
Hi,
I am new in statistics and i manage to make the linear model analysis but i
have some difficulties in explaining the results. Can someone help me
explalinig the output of my linear model analysis ? My data are with 2
variables habitat (e,s) and treatment (a,c,p) with multiple trials within.
Thank you in advance
Call:
lm(formula = a$wild ~ a$habitat/a$treatment/a$trial)
Residuals:
Min
2005 Feb 24
3
a simple question
Dear All,
I need to separate one column which is in a format like, "can_region",
into two columns like, "can", and "region". Do we have a function in R
to do this? Thanks.
Regards,
Jin
[[alternative HTML version deleted]]
2011 Nov 22
0
Error in gls function in loop structure
Hi, r-users
I got a problem when I try to call a *gls* function in loop structure.
The gls function seems not able to recognize the parameters that I pass
into the loop function!
(But, if I use lm function, it works.)
The code looks like this:
=================================================
gls.lm <- function(Data, iv1, dv1)
{
gls.model <- gls(Data[ , dv1] ~ Data[ , iv1], correlation =
2006 Apr 23
1
Question about bicreg
Dear Adrian and Ian (and r-helpers),
I encountered a curious result in developing an example using the bicreg
function in the BMA package: I noticed that pairs of models with equal R^2
and equal numbers of predictors had nevertheless different BIC values.
Looking at the bicreg function, the definition of BIC appears to be the
usual one, or close to it [bic <- n * log(1 - r2/100) + (size - 1) *
2018 Apr 18
2
Comparing Indexing Speed + ZFS question
Hi, have two quick questions:
I am re-indexing some large mailboxes and I wanted to get some opinions on these speeds. I ran a random sort command on an unindexed mailbox in order to get it to index. Results, for a mailbox with 10GB Inbox, spread in 65 000 files:
3 UID SORT (ARRIVAL) US-ASCII OR OR OR FROM "dfgfgfgf" SUBJECT "dfgfgfgf" TO "dfgfgfgf" CC
2004 Sep 20
4
IPv6 routing question - corrected
* sorry for the other schema, it came out a mess. I hope this one is
understandable.
hi:
I have this 2 boxes set up like this:
2020::2/128
2020::254/128 3030::254/128
192.168.0.2/24 192.168.0.254/24
192.168.30.254/24
+-------+ eth0 eth3
+-------+
2012 Dec 09
3
[LLVMdev] pb05 benchmarks for llvm/dragonegg 3.2
Duncan,
With the commit from http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20121203/158488.html,
the Polyhedron 2005 benchmarks complete again on x86_64-apple-darwin12. The result are similar to what
were seen with FSF gcc 4.6.2svn and llvm/dragonegg 3.0 (which was the last release that passed pb05)
http://lists.cs.uiuc.edu/pipermail/llvmdev/2011-October/044091.html.
Jack
2011 Oct 11
2
Creating the mean using algebra matrix
Dear all,
I wanted to create the mean using a algebra matrix.
so I tried this one:
> meanAnimals <- new3%*%factorial
(Calculates the matrix multiplication of the new3 * factorial).
But I get the following error message:
Error in new3 %*% factorial : non-conformable arguments
These are my matrices:
> new3
[,1] [,2]
[1,] 1.350 8.1
[2,] 465.000 423.0
2007 Mar 01
7
count the # of appearances...
Hi there,
is there a possibility to count the number of appearances of an
element in a vector ?
i mean of any given element.. deliver all elements which are exactly
xtimes in this vector ?
thx in advance !!
2005 Oct 03
2
interpolation using akima (PR#8174)
Full_Name: Jonathan Lees
Version: 2.0.1
OS: linux-gnu
Submission from: (NULL) (152.2.75.65)
there is a problem with calculating the convex hull in 2-D interpolation using
the codes interp fromt eh akima package:
x =c(0.6505304, -1.1821562, -0.2600792, 0.7913716)
y = c(1.0424226, 0.1754048, -1.4523334, 0.2349112)
z = c(0.000, 3.042, 0.370, 0.122)
EX = seq(from=min(x), to=max(x),