Displaying 20 results from an estimated 1000 matches similar to: "chi-square and error bars?"
2003 Apr 22
4
fisher exact vs. simulated chi-square
Dear All,
I have a problem understanding the difference between the outcome of a
fisher exact test and a chi-square test (with simulated p.value).
For some sample data (see below), fisher reports p=.02337. The normal
chi-square test complains about "approximation may be incorrect",
because there is a column with cells with very small values. I
therefore tried the chi-square with
2011 Sep 06
1
"Continious Repo" vs. 'normal' Centos-Base/Updates questions
I have some questions about the "Continious Repo".
Does the "Continious Repo" replace the Centos-Base/Updates repo?
Is the "Continious Repo" in a standard place on the CentOS mirrors? Ie.
can I just add another line to my rsync script to get this repo? It is
not possible for me to just update directly off the net (I have a slow
and unreliable network connection)
2013 Sep 22
2
Arcsine transformation
I am tryin to perform an arcsine transformation on my data containig
percentages as the dep. variable. Does anyone have a code that I could use
to do that? I am relatively new to R. Thanks for your help!
--
View this message in context: http://r.789695.n4.nabble.com/Arcsine-transformation-tp4676706.html
Sent from the R help mailing list archive at Nabble.com.
2012 Sep 27
1
What to use for ti in back-transforming summary statistics from F-T double square-root transformation in 'metafor'
Hi Dr. Viechtbauer,
I'm doing meta-analysis using your package 'metafor'. I used the 'IRFT' to transform the incident rate. But when I tried to back-transform the summary estimates from function rma, I don't know what's the appropriate ti to feed in function transf.iirft. I searched and found your post about using harmonic mean for ni to back-transform the double
2011 Apr 14
1
Error is assocplot
Hello,
I have a contingency table showing relation between two datasets. I tried
to see association among them with the assocplot, but it shows
error. mosaicplot of the same data worked perfectly.
Can anyone please help me.
Con.table=as.matrix(Con.table)
> dim(Con.table)
[1] 27 27
> assocplot(Con.table,space = 0.3,
+ main = NULL, xlab = NULL, ylab = NULL)
Error in
2007 Mar 13
1
Freeman-Tukey arcsine transformation
R-Experts:
Does anyone know if there are R functions to perform the Freeman-Tukey
double arcsine transformation and then backtransform it?
Thanks,
Brant Inman
Mayo Clinic
2010 Jun 09
1
back transforming arcsine transformations in metafor
Hi everyone,
I'm using the metafor package to meta-analyze a set of proportions. This is working really well for the raw proportions, but is there a way to back-transform the arcsine transformed proportions in the rma or forest functions with the atransf option? The estimates and CIs for the transformed proportions need to be back-transformed to be the sin of the estimate squared.
2011 Mar 14
1
Help- Fitting a Thin Plate Spline
Hi Everyone,
I'm a pretty useless r-er but have data that SPSS etc doesn't like. I've
managed to do GLMs for my data, but now need to fit a thin plate spline for
my data (arcsine.success~date.num:clutch.size)
If anyone has a bit of spare time and could come up with a bit of code I'd
be very grateful- I just don't get R language!
Thanks
Rach
--
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2008 Apr 30
2
arcsine transformation
I have been trying to preform both a bartlett's test and an arcsine
transformation on some average percentage data. I've tried inputting it
different ways and I keep getting the same error message:
> head(workingdata)
DYAD BEFORE AFTER
1 BG-FL 4.606772 5.787520
2 BG-LL 5.467503 7.847395
3 AD-MV 5.333735 11.107380
4 MM-FL 5.578708 12.063500
5 MM-MV 2.037605 6.415303
6 MM-RM
2005 Jan 27
4
self-written function
Dear all,
I?ve got a simple self-written function to calculate the mean + s.e.
from arcsine-transformed data:
backsin<-function(x,y,...){
backtransf<-list()
backtransf$back<-((sin(x[x!="NA"]))^2)*100
backtransf$mback<-tapply(backtransf$back,y[x!="NA"],mean)
2005 Mar 18
1
Cisco 7940 convert to sip
Hi!
Can anybody help me with convert Cisco 7940 CallManager Phone to
a SIP Phone? I have continious error in tftp log:
connect from 192.168.1.111
Mar 18 12:12:30 AKrasavin utftpd[10081]: peer requests
OS79XX.TXT, conversion octet
Mar 18 12:12:30 AKrasavin utftpd[10081]: unterminated option
value in init packet
Mar 18 15:12:30 AKrasavin xinetd[10068]: START: tftp pid=10080
from=192.168.1.111
Mar
2010 Jul 14
1
Arrange values on a timeline
I have a set of labels arranged along a timeframe in a. Each label has
a timestamp and marks a state until the next label. The dataframe a
contains 5 such timestamps and 5 associated labels. This means, on a
continious scale between 1-100, there are 5 markers. E.g. 'abc' marks
the timestampls between 10 and 19, 'def' marks the timestamps between
20 and 32, and so on.
a <-
2009 May 06
2
Need help building combined model
I have two kind of variables. One kind where the values are continious and ranges from -1 to 5, and the other is boolean (i.e. true or false).
For example:
V1 V2 V3 V4 V5 V6
0.1 0.4 1 0 -1 3.7
0.4 0.1 2 -1 0 3.7
and
V1 V2 V3
0 1 0
0 0 1
I want to make a model for classification, combining this two. Will it be wiser to use the second variable values
2010 Dec 20
1
Metafor package
I have some question about metafor package.
I'm interest to perform a random effect meta-analysis of proportion
(single group summary of prevalence of disease in a population as
reported by different study)
It ask:
1. "PFT": The Freeman-Tukey double arcsine transformed proportion is
reported to be equal to 1/2*(asin(sqrt(xi/(ni+1))) +
asin(sqrt((xi+1)/(ni+1)))). Hovewer, i
2017 Aug 24
3
Are r2dtable and C_r2dtable behaving correctly?
Hello,
While doing some enrichment tests using chisq.test() with simulated
p-values, I noticed some strange behaviour. The computed p-value was
extremely small, so I decided to dig a little deeper and debug
chisq.test(). I noticed then that the simulated statistics returned by the
following call
tmp <- .Call(C_chisq_sim, sr, sc, B, E)
were all the same, very small numbers. This, at first,
2017 Aug 25
2
Are r2dtable and C_r2dtable behaving correctly?
It is not about "really arge total number of observations", but:
set.seed(4711);tabs <- r2dtable(1e6, c(2, 2), c(2, 2)); A11 <- vapply(tabs, function(x) x[1, 1], numeric(1));table(A11)
A11
0 1 2
166483 666853 166664
There are three possible matrices, and these come out in proportions 1:4:1, the one with all cells filled with ones being
most common.
Cheers, Jari
2016 Apr 15
1
Heteroscedasticity in a percent-cover dataset
Hi,
I am currently trying to do a GLMM on a dataset with percent cover of
seagrass (dep. var) and a suite of explanatory variables including algal
(AC) and epiphyte cover (EC), rainfall, temperature and sunshine hours.
M2=glmer(SG~AC+EC+TP+SS+RF+(1|Location/fSi/fTr),
family=binomial,data=data,nAGQ=1)
As the dependent variable is percent cover, I used a binomial error
structure. I also have a
2007 Oct 17
1
Error message in GAM
Hello useRs!
I have % cover data for different plant species in 300 plots, and I use
the ARCSINE transformation (to deal with % cover data).
When I use a GLM I do not have any problem.
But when I am trying to use a GAM model using mgcv package, to account for
non-linearity I get an ?error message?.
I use the following model:
sp1.gam<-gam(asin(sqrt(0.01*SP1COVER))~
2005 Mar 03
1
Negative binomial regression for count data
Dear list,
I would like to fit a negative binomial regression model as described in "Byers AL, Allore H, Gill TM, Peduzzi PN., Application of negative binomial modeling for discrete outcomes: a case study in aging research. J Clin Epidemiol. 2003 Jun;56(6):559-64" to my data in which the response is count data. There are also 10 predictors that are count data, and I have also 3
2011 Jul 06
2
wgcna
Hi,
I'm running a tutorial ("Meta-analyses of data from two (or more) microarray data sets"), which use wgcna package. I have an error in the function modulePreservation (it is below).
I'm using R2.13
Can you help me? Do you know, what is happens?
Thanks
Raquel
multiExpr = list(A = list(data=t(badea)),B = list(data=t(mayo)))
# two independent datasets (dim = 13447 x 36)
mp =