Displaying 20 results from an estimated 1000 matches similar to: "R function to compute kappa statistics for two vector"
2006 Apr 28
1
Where do I find Cohen´s kappa???
Hello,
I?m looking for a way to measure the goodness of fit of my model with Cohen?s Kappa (scaling between 0 and 1).
The kappa function does not give the results I?m looking for. Heres the code:
z<-glm(x~y,binomial)
kappa(z, exact = T)
Does anyone know more?
many thanks
Christian
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2006 Aug 10
1
logistic discrimination: which chance performance??
Hello,
I am using logistic discriminant analysis to check whether a known
classification Yobs can be predicted by few continuous variables X.
What I do is to predict class probabilities with multinom() in nnet(),
obtaining a predicted classification Ypred and then compute the percentage
P(obs) of objects classified the same in Yobs and Ypred.
My problem now is to figure out whether P(obs) is
2010 May 25
1
Cohen's Kappa for beginners
Hi,
I've got two vectors with ratings from two coders, like this:
x<-c("red", "yellow", "blue", "red") #coder number 1
y<-c("red", "blue", "blue", "red") #coder number 2
I want to find Cohen's Kappa using the wkappa function in the psych
package. The only example in the docs is using a matrix, which
2009 Dec 22
1
Cohen's kappa, unequal score ranges
Hi,
I am having problems getting cohen's kappa to work. I have been using the function:
><-ckappa(x,y)
from the psy package.
I am trying to test for inter-observer reliability, I have 2 observers and 26 categories, however, the two observers might not necessarily have the same range of categories (I have unequal score ranges). However, I thought R could cope with this.
Each time I
2005 Aug 05
1
kappa-accuracy and test for signifcance
Dear list,
I calculated the kappa-accuracy for two differnt classifications.
How can I test now the two kappa-value for significance?
thanks, Mark
.....................................................................
Markus Schwarz
Wissenschaftliche Mitarbeiterin
Eidg. Forschungsanstalt WSL
Forschungsprogramm Musterland
Z??rcherstrasse 111
CH-8903 Birmensdorf
Telefon +41-44-739 22 87
Fax
2008 Sep 07
1
cohen's kappa
Dear all,
I have a question on Cohen's kappa:
Assume I have two datasets, one has 500 objects, 10 methods and the other,
1000 different objects, 20 different methods. Could I compare between the
two datasets to conclude the 10 methods are more "concordant" than the 20
ones by looking at some output, for example, cohen.kappa{concord} ?
One more, could anyone explain in brief,
2009 Jul 13
3
Help With Fleiss Kappa
Hi All,
I am using fleiss kappa for inter rater agreement. Are there any know
issues with Fleiss kappa calculation in R? Even when I supply mock data
with total agreement among the raters I do not get a kappa value of 1.
instead I am getting negative values.
I am using the irr package version 0.70
Any help is much appreciated.
Thanks and Regards
M
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2006 Dec 11
1
cohen kappa for two-way table
Greetings,
I am a bit confused by the results returned by the functions:
cohen.kappa {concord}
classAgreement {e1071}
when using a two-way table.
for example, if I have an matrix A, and a similar matrix B (same
dimensions), then:
matrix A and B can be found:
http://casoilresource.lawr.ucdavis.edu/drupal/files/a_40.txt
http://casoilresource.lawr.ucdavis.edu/drupal/files/b_40.txt
A <-
2007 Mar 27
1
basic handling of data.frame
Hello,
I'm new to R but wan't to use it to compute the statistics of my medical study.
The study includes several parameters for a number of patients. Each
parameter was assessed by a number of readers, once with a special
condition, once without.
Now I have a data.frame with colums like:
PatientID, ReaderID, SpecialCond(yes/no), Parameter1, Parameter2.....
the rows are not sorted, and
2008 Oct 31
1
stratified kappa (measure agreement or interrater reliability)?
Hi All:
Could anyone point me to a package that can calculate stratified kappa? My
design is like this, 4 raters, 30 types of diagnosis scores, 20 patients.
Each rater will rate each patient for each type of diagnosis score. The
rater's value is nominal.
I know I can measure the agreement between raters for each type of diagnosis
score, e.g., calculate out 30 kappa values. My problem is I
2007 Jun 26
3
inter-rater agreement index kappa
Is there a function that calculates the inter-rater agreement index
(kappa) in R?
Thanks ../Murli
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2005 Jun 15
1
(no subject)
Are there functions available computing the gamma-correlation for ordinal
scaled variables and kappa-accuracy for nominal variables,
thanks, Mark
...........................................................................
Swiss Federal Institute for Forest, Snow and Landscape Research
Zuercherstrasse 111 - 8903 Birmensdorf - Switzerland
e-mail: markus.schwarz at wsl.ch
www:
2007 Mar 22
3
Cohen's Kappa
Hi,
im little bit confused about Cohen's Kappa and i should be look into the
Kappa function code. Is the easy formula really wrong?
kappa=agreement-chance/(1-chance)
many thanks
christian
###############################################################################
true-negativ:7445
false-positive:3410
false-negativ:347
true-positiv:772
classification-aggrement:68,6%
2018 Apr 26
2
kappa
Buenas, ¿alguien sabe qué puede ser este error?
data es una df y las columnas 23 y 24 son las que quiero comparar; están bien.
testK<-kappa2(data[,c(23,24)], "equal")
Error in sort.list(y) : 'x' must be atomic for 'sort.list'
Have you called 'sort' on a list?
--
Dr Manuel Mendoza
Department of Biogeography and Global Change
National Museum of Natural
2011 Jun 22
1
caret's Kappa for categorical resampling
Hello,
When evaluating different learning methods for a categorization problem with
the (really useful!) caret package, I'm getting confusing results from the
Kappa computation. The data is about 20,000 rows and a few dozen columns,
and the categories are quite asymmetrical, 4.1% in one category and 95.9% in
the other. When I train a ctree model as:
model <- train(dat.dts,
2012 Feb 01
1
Function to compute multi-response, multi-rater kappa?
I'm looking for a function in R that extends kappa to multiple raters when
there is more than one response per subject. For example, say a group of
doctors have to assign diseases to patients. Each patient will be assigned
one to many diseases, and the number of doctors assigning diseases to any
one patient will be two to many.
Here's an extremely simple example of the type of data I
2008 Aug 22
3
simple generation of artificial data with defined features
Dear R-colleagues,
I am quite a newbie to R fighting my stupidity to solve a probably quite
simple problem of generating artificial data with defined features.
I am conducting a study of inter-observer-agreement in
child-bronchoscopy. One of the most important measures is Kappa
according to Fleiss, which is very comfortable available in R through
the irr-package.
Unfortunately medical doctors
2010 Oct 13
2
Using NLS with a Kappa function
Hi Everyone,
I am trying to use NLS to fit a dataset using a Kappa function, but I am
having problems. Depending on the start values that I provide, I get
either:
Error in numericDeriv(form[[3L]], names(ind), env) :
Missing value or an infinity produced when evaluating the model
Or
Error in nls(FldFatRate ~ funct3(MeanDepth_m, h, k, z, a), data = data1, :
singular gradient
I think these
2013 Jan 11
0
Weighted Kappa for m Raters
Hello, I have 50 raters and 180 cases which are rated as malignant, probably malignant, probably benign, and benign. I want to compare all the raters but I want a weighted kappa to penalize differences between malignant and benign more than differences between malignant and probably malignant. I only found the weighted option in the 2-rater functions (kappa2, wkappa, cohen.kappa). The
2008 May 29
1
Kappa distribution
Hallo all,
I am looking for an R implementation of the four parameter kappa
distribution (cdf, pdf, quantile, and ransom numbers), or at a minimum,
the generalized logistic distribution.
Any suggestions?
Thank you very much,
Serguei