Displaying 20 results from an estimated 1000 matches similar to: "complex contrasts and logistic regression"
2011 Jul 18
1
Missing values and geeglm
Dear all
I am struggling with how to deal with missing values using geeglm. I know
that geeglm only works with complete datasets, but I cannot seem to get the
na.omit function to work. For example
assuming DataMiss contains 3 columns, each of which has missing
observations, and an id column with no missing info then identifies the
clusters.
Outcome: 2 level integer
Predictor: numeric variable
2011 Jun 07
3
Logistic Regression
I am working on my thesis in which i have couple of independent variables
that are categorical in nature and the depndent variable is dichotomus.
Initially I run univariate analysis and added the variables with significant
p-values (p<0.25) in my full model.
I have three confusions. Firstly, I am looking for confounding variables by
using formula "(crude beta-cofficient - adjusted
2007 Dec 04
2
Learning to do randomized block design analysis
We just studied randomized block design analysis in my statistics class,
and I'm trying to learn how to do them in R. I'm trying to duplicate a
case study example from my textbook [1]:
> # Case Study 13.2.1, page 778
> cd <- c(8, 11, 9, 16, 24)
> dp <- c(2, 1, 12, 11, 19)
> lm <- c(-2, 0, 6, 2, 11)
> table <- data.frame(Block=LETTERS[1:5], "Score
2011 Oct 03
1
Assigning factor names to interaction plot
Hi everyone,
I have the following problem:
I have three variables, 'group', 'city' and 'pressure'
There is an interaction effect between group and city and I'd like to show
this in an interaction plot:
interaction.plot(group, city, pressure, type="b",
col= c(1:2),
leg.bty="o", leg.bg="blue", lwd=1,
2013 Feb 13
2
NA/NaN/Inf in foreign function call (arg 6) error from coxph function
Dear R-helpers:
I am trying to fit a multivariate Cox proportional hazards model,
modelling survival outcome as a function of treatment and receptor
status. The data look like below:
# structure of the data
str(sample.data)
List of 4
$ survobj : Surv [1:129, 1:2] 0.8925+ 1.8836+ 2.1191+ 5.3744+
1.6099+ 5.2567 0.2081+ 0.2108+ 0.2683+ 0.4873+ ...
..- attr(*, "dimnames")=List of 2
2006 May 30
1
rake db_schema_import on vanilla schema.rb
Hi all,
I dumped my schema from SQLServer 2000 without any problems. I then
tried to "rake db_schema_import" on MySQL 4. To do this i changed my
database.yml settings to use the mysql adapter (as it was set to use
sqlsever before) and attempted the import.
I haven''t changed a thing in the schema.rb script and, even though I do
have generated a migration, I think I
2012 Feb 24
1
code for mixed model in R?
Dear
I am analysing my data wit a mixed model. I used SAS but I want to redo the
same analysis in R. Here the SAS code and what I wrote in R. It seems to
work but the results are not the same. I don't know how to specify the class
variable in R or specify the variance matrix. Can you please help me?
Thanks
Jurgen
## SAS:
proc glimmix data=trend method=RSPL;
class pid;
model mdrfinal
2009 Nov 02
1
Interaction contrasts or posthoc test for glm (MASS) with ANOVA design
Dear R experts
I am running a negative-binomial GLM (glm.nb) to test the null hypotheses
that species 1 and 2 are equally abundant between site 1 and site2, and
between each other. So, I have a 2x2 factorial design with factors Site
(1,2) and Taxon (1,2).
Since the Site:Taxon interaction is significant, I need to do the equivalent
to a "post-hoc test" for ANOVA, however, the same tests
2013 Jun 28
2
Puppet user running Apache-Passenger ?
Is there anything in the Puppet/Passenger setup process that edits httpd.conf and sets the User/Group running apache to "puppet" ?
A master I set up several months ago is configured that way.
I do not recall doing it.
But then the high voltage electroshock therapy does have its side effects :)
“Sometimes I think the surest sign that intelligent life exists elsewhere in the
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]]
2006 Jan 02
3
ANN: new rails site/RoR praise
Hi,
>From idea to launch in less than 48 hours (those 48 hours including
the new year party ;) , rails once again showed its effectiveness.
Last friday I read the news about a guy who sold a million pixels for
1$ each on his homepage. After slamming my head during half an hour
for not having thought of it [1], I thought I''d better spend some time
on a rails project, and more as a
2004 Mar 06
2
normal scores test
Hello,
I need help in performing a Van_der_Waerden normal scores test in R. I
have two arrays of scores(final on therapy scores from drug and placebo) and
want to use the normal scores procdeure to test for significance.
(observations are unequal in number - due to dropouts). Could you please help
me out with the coding or let me know if there is a package that can be used
(for example,
2018 Jan 16
1
Letters group Games-Howell post hoc in R
Hello everybody,
I use the sweetpotato database included in R package:
data(sweetpotato) This dataset contains two variables: yield(continous
variable) and virus(factor variable).
Due to Levene test is significant I cannot assume homogeneity of variances
and I apply Welch test in R instead of one-way ANOVA followed by Tukey
posthoc.
Nevertheless, the problems come from when I apply posthoc
2013 Dec 18
1
Fwd: Bad \usage lines question
Dear colleagues,
In checking a function I am adding to an R package, I get the following
warning pair:
...
Bad \usage lines found in documentation object 'nominal':
"\\method{print}{nominal}"(x, max.print = 10,
posthoc = "std.pearson.residuals.sign",
assoc = ifelse("univariate"
list(c("N", "alpha.X2",
2008 Dec 04
1
Changing 'record' option in open graphics device
Hi,
I am wondering if there is a way to change the value of the "record" option
in a graphics device that is already open (and accepts this option). I
don''t want to open a new device with, for example "dev.new(record=T)", but
just want to change the settings of the current device. This can be done by
pointing and clicking on the "history" tab of a
2012 May 21
1
Complex text parsing task
Hello Everyone,
I have what I think is a complex text parsing task. I've provided some sample data below. There's a relatively simple version of the coding that needs to be done and a more complex version. If someone could help me out with either version, I'd greatly appreciate it.
Here are my sample data.
haveData <-
structure(list(profile_key = structure(c(1L, 1L, 2L, 2L, 2L,
2007 Jan 09
2
posthoc tests with ANCOVA
dear all,
I want to perform a posthoc test for my ANCOVA:
a1<-aov(seeds~treatment*length)
With
summary(glht(a1, linfct = mcp(treatment = "Tukey")))
R tells me: "covariate interactions found -- please choose appropriate
contrast"
How do I build these contrasts?
Ideally, I would like to have the posthoc test for the ANCOVA including
a block-effect
2010 Oct 20
1
Please help: ANOVA with SS Type III for unequal sample sized data
Dear R experts,
I'm beginner.
My question about ANOVA for unequal sample sized data should be obsolete but
I can not clarify it.
I have a dataset from 23 males and 18 females.
I measured one condition('cond') with 4 levels.
So I'd like to see main effect of gender, cond and gender by cond
interaction and also postHoc test. (In fact, I have to do anova 90 times)
*
1. Question
2013 Sep 01
0
Question About Markov Models
Dear All,
I am a bit struggling with the many packages for Markov models available
in R.
Apologies for now posting a code snippet, but I am looking for some
guidance here.
Please consider a set like the one below (which you can get with
data<-read.csv('http://dl.dropboxusercontent.com/u/5685598/data_table.csv')
).
ID therapy age1 age2 EFS
7308 ormo_lunga 78
2010 Mar 04
1
mysqlWriteTable . error in your SQL syntax?
Hi,
Can somebody advice on weird mysqlWriteTable bug.
> mysqlWriteTable(conn, 'comparison',design2, row.names = F, overwrite=T)
Error in mysqlExecStatement(conn, statement, ...) :
RS-DBI driver: (could not run statement: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '"condition"