Displaying 17 results from an estimated 17 matches similar to: "arcsine transformation"
2011 Dec 23
1
Long jobs completing without output
I've been running a glmer logit on a very large data set (600k obs).
Running on a 10% subset works correctly, but for the complete data set,
R completes apparently without error, but does not display the results.
Given these jobs take about 200 hours, it's very hard to make progress
by trial and error.
I append the code and the sample and complete output. As is apparent, I
upgraded R
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.
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.
2014 Mar 07
2
[LLVMdev] [RFC] BlockFrequency is the wrong metric; we need a new one
On Feb 4, 2014, at 4:36 PM, Andrew Trick <atrick at apple.com> wrote:
>
> On Feb 4, 2014, at 4:07 PM, Duncan P. N. Exon Smith <dexonsmith at apple.com> wrote:
>
>>
>> On Feb 3, 2014, at 12:13 AM, Andrew Trick <atrick at apple.com> wrote:
>>
>>> On Feb 2, 2014, at 6:55 PM, Chandler Carruth <chandlerc at gmail.com> wrote:
>>>
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)
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
--
View this message in context:
2005 Jan 18
1
chi-square and error bars?
This may sound crazy but...
I have data like this...
> results.matrix
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12]
[1,] 949 93 2 11 26 20 7 6 10 5 0 3
[2,] 1233 124 24 35 58 57 17 21 31 19 11 21
Which is the result of binning (summing) the response variables of an
underlying (nearly) continious range of predictor
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
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
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))~
2011 Jun 20
0
Activity budgets with multiple proportions as response
Hi everyone,
I've searched the internet and lots of stats books high and low for this one, but nothing seems to be quite what I want. I've got continuous data on four different state activities recorded in seconds, however each continuous session is not equally long, so the data are best expressed as proportions, i.e.: Subject 1: Swimming, 0.5, Hiding, 0.25, Edge, 0.125, Inactive, 0.125
2008 Oct 24
1
pwr.2p2n.test when the ratio of n1/n2 is known
Hi,
I am trying to do a power calculation for a difference in proportions
test where I want to estimate the sample size required. I know (well
estimate) that group one (n1) is 10% of the population and group 2 (n2)
is 90% of the population. I know the effect size (h). pwr.2p2n.test
only allows one variable to be left null whereas I would like both n1
and n2 to be determined where I know there
2005 Jan 25
1
Box-Cox / data transformation question
Dear R users,
Is it reasonable to transform data (measurements of plant height) to the
power of 1/4? I?ve used boxcox(response~A*B) and lambda was close to 0.25.
Regards,
Christoph
2012 Mar 19
3
Issue with asin()
Hello everyone,
I am working for a few days already on a basic algorithm, very common in
applied agronomy, that aims to determine the degree-days necessary for a
given individual to reach a given growth stade. The algorithm (and context)
is explained here: http://www.oardc.ohio-state.edu/gdd/glossary.htm , and
so I implemented my function in R as follows:
DD <- function(Tmin, Tmax, Tseuil,
2010 Dec 15
1
Using Metafor package: how to backtransform model coefficients when Freeman Tukey double arcine transformation is used
Hello,
I am performing a meta-analysis using the metafor package. My data are
proportions and I used the Freeman Tukey double arcine (FT)
transformation to fit the random effects model. Now I want to create a
forest plot with my estimates backtransformed to the original scale of
proportions. Can this be done?
Regards,
Patricia