Displaying 20 results from an estimated 10000 matches similar to: "please help!"
2010 Jun 16
2
qplot
Hello,
I am a new r-user, and after a great effort I have made this fantastic
figure with qplot:
qplot(ROI, CBF, fill=factor(Carrier), data=combinedboxplot_dataset_se_1_CBF,
geom="boxplot", position="dodge",xlab=NULL,ylab=("CBF,white
matter-normalized"),main=("Differences between carriers and non-carriers on
baseline"))+theme_bw()
Can anyone help me
2008 Sep 03
2
ANCOVA/glm missing/ignored interaction combinations
Hi
I am using R version 2.7.2. on a windows XP OS and have a question
concerning an analysis of covariance with count data I am trying to do,
I will give details of a scaled down version of the analysis (as I have
more covariates and need to take account of over-dispersion etc etc) but
as I am sure it is only a simple problem but I just can't see how to fix
it.
I have a data set with count
2009 Aug 20
1
nested, repeated measure lme
Dear all,
Suppose I have a nested, repeated measure lme model. Which of the following formulae is correct?
(assuming data are sampled from several plots in an agricultural experiment)
(1) y~explanatory.variables,random=~time|block/plot/subplot/individual
(2) y~explanatory.variables,random=~time|unique.ID.of.every.individual
I have read that (2) is the only approach that works. But how could I
2012 Aug 10
2
Simple question about formulae in R!?
Good morning reader,
I have encountered a, probably, simple issue with respect to the *formulae* of
a *regression model* I want to use in my research. I’m researching
alliances as part of my study Business Economics (focus Strategy) at the
Vrije Universiteit in Amsterdam. In the research model I use a moderating
variable, I’m looking for confirmation or help on the formulation of the
model.
2010 Aug 03
2
subset based on column names and then subset based on the inverse (grep?, or...)
I would like to be able to grab x and y columns out of a dataframe and
then grab all of the columns that are not equal to x or y. I am sure
that I am missing something easy.
ftbr_UTM_downstream <- (structure(list(site =
c("Jennie_Creek_Main_Stem", "Wolf_Pit_Creek_Main_Stem",
"Little_Rockfish_Main_Stem_North", "Big_Muddy_Creek_Main_Stem",
2011 Mar 31
2
Linear Model with curve fitting parameter?
I have a model Q=K*A*(R^r)*(S^s)
A, R, and S are data I have and K is a curve fitting parameter. I
have linearized as
log(Q)=log(K)+log(A)+r*log(R)+s*log(S)
I have taken the log of the data that I have and this is the model
formula without the K part
lm(Q~offset(A)+R+S, data=x)
What is the formula that I should use?
Thanks for all of your help. I can provide a subset of data if necessary.
2013 May 01
3
Chron format question h:m not working
R 2.12.2 on Scientific Linux 6.4
#works
chron(times.="15:00:00", format=c(times="h:m:s"))
#doesn't work
chron(times.="15:00", format=c(times="h:m"))
From chron Manual:
The times format can be any permutation of "h", "m", and "s" separated
by any one non-special character. The default is "h:m:s".
what am I
2009 Sep 04
1
Linear Contrasts in GLM - Query
Hi,
Is there a way I can specify linear contrasts in glm? I'm looking for
something equivalent to SAS' contrast statement.
I'd like to do the following, suppose I have a categorical input with 4
levels (a,b,c,d), I'd like to test something like: (i) a+b=c+d, (ii) a=b,
(iii) a=b+d, etc...
Thanks in advance for your help!
Leo.
[[alternative HTML version deleted]]
2009 Sep 04
2
plot positive predictive values
Hi,
I'm trying to fit a smooth line in a plot(y ~ x) graph.
x is continuous variable
y is a proportion of success in sub-samples, 0 <= y <= 1, from a Monte
Carlo simulation.
For each x there may be several y-values from different runs. Each run
produces several sub-samples, where "0" mean no success in any sub-
sample, "0.5" means success in half of the
2006 Oct 05
4
glm with nesting
I just had a manuscript returned with the biggest problem being the
analysis. Instead of using principal components in a regression I've
been asked to analyze a few variables separately. So that's what I'm
doing.
I pulled a feather from young birds and we quantified certain aspects of
the color of those feathers. Since I often have more than one sample
from a nest, I thought I
2009 Mar 24
2
modelling probabilities instead of binary data with logistic regression
Dear all,
I have a dataset where I reduced the dimensionality, and now I have a
response variable with probabilities/proportions between 0 and 1. I wanted
to do a logistic regression on those, but the function glm refuses to do
that with non-integer values in the response. I also tried lrm, but that one
interpretes the probabilities as different levels and gives for every level
a different
2012 May 11
1
ANOVA question
Hello all,
I'm very satisfied to say that my grip on both R and statistics is
showing the first hints of firmness, on a very greenhorn level.
I'm faced with a problem that I intend to analyze using ANOVA, and to
test my understanding of a primitive, one-way ANOVA I've written the
self-contained practice script below. It works as expected.
But here's my question: How can I not
2011 Apr 16
2
(no subject)
I have just upgraded to R 2.13 and have library(ggplot2) in my
.Rprofile (among other things). when i start R I get an error
message. Has something in the start up scripts changed? Is there a
better way to specify the library calls in .Rprofile? Thanks for all
of the help in advance.
Error:
Loading required package: grid
Loading required package: proto
Error in rename(x, .base_to_ggplot) :
2010 Sep 08
1
problem with max in a function
s <- 1.00
max(s)
returns 1
is there anyway that I can get it to return 1.00. I am using the
results of this max statement in a grep statement and it returns the
wrong numbers, I will provide more information and code if it would
make more sense in context.
--
Stephen Sefick
____________________________________
| Auburn University? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?? |
| Department of
2008 Oct 15
2
apply model predictions over larger area with predict()
Dear all,
I have built glm models based on presences/absences and a number of
predictor maps and would like to compute habitat suitability based on
the modelled coefficients.
I thought this is pretty straight forward and wanted to use predict()
and supply the new data in a data frame, with one column for each
predictor.
However, I do get an error msg warning me that the number of rows for
2012 Jul 18
1
ggplot2 qplot pch not working anymore
Is there a way to use a continuous variable to pch in qplot? I believe
this worked in previous version. I need to specify certain values of a
shape for particular points so that multiple graphs all show the same
shapes for the same streams. I have gone to the original data and added
a pch column that I would like to use to specify the shapes to pch in
qplot. Any help would be greatly
2009 Jul 29
3
predict
I have found a regression model, and i would like to predict value in
different points. I have tried to use predict function but it doesn't work.
I have used predict function like this:
newdata<-seq(from=0.1, to=0.32,by=0.02)
data<-predict(fm,newdata)
where fm is a regression model. The predict function return me that:
Error in eval(predvars, data, env) : numeric argument
2012 Nov 16
2
source file on startup question - why does an old version of a function show up? ggplot or R?
All,
1. I will try and make this clear and concise. Please let me know any
information that would be helpful in figuring out this problem (I don't
know the relevant information to post). I am on linux- see below for
session information.
2. Problem:
working directory: home
an old version of a function is sourced into the R session and doesn't work
working directory: Desktop
the
2012 Nov 07
1
A warning message in glht
Dear all,
I was wondering if you could give me any suggestions/help on the following
issue. So I carried out the analysis of my data using generalized linear
model (glm). After that, to check for multiple comparisons, I applied the
glht function from the multcomp package in R. The output, however, gave me a
warning (please see below). So my question is whether this warning is smth
that I should
2013 Dec 17
1
ggplot2: stat_smooth for family=binomial with cbind(Y, N) formula
With ggplot2, I can plot the glm stat_smooth for binomial data when the
response is binary or
a two-level factor as follows:
data("Donner", package="vcdExtra")
ggplot(Donner, aes(age, survived)) +
geom_point(position = position_jitter(height = 0.02, width = 0)) +
stat_smooth(method = "glm", family = binomial, formula = y ~ x,
alpha = 0.2, size=2)
But how can I