Displaying 20 results from an estimated 700 matches similar to: "error:max not meaningful for factors"
2014 Jun 23
2
Resumen de R-help-es, Vol 64, Envío 33
Hola, Marta,
Por lo que he podido ver tus datos ya tienen calculados las tasas de verdaderos y falsos positivos (TPR y FPR). También parece que los tienes ordenados por la variable FishSpeed y supongo que también por las que parecen marcas de tiempo. No necesitas ROCR porque con un simple plot te sale algo parecido a una curva. Eso sí, veo que son medidas repetidas en el tiempo para cada valor de
2014 Jun 20
2
Como construir una curva ROC
Hola!
Tengo que hacer una curva ROC com unos datos que obtuve de hacer una macro
de excel y aplicar unas reglas, y basicamente tengo que a partir de la
variacion del tiempo y la velocidad del barco obtengo diferentes
porcentajes de true positives (TP) y false positives (FP) y con eso deberia
de construir una curva ROC.
Dada mi ignorância en este tema, no se muy bien por donde empezar , estuve
2009 Feb 25
3
Using package ROCR
I am trying to use package ROCR to analyze classification accuracy,
unfortunately there are some problems right at the beginning.
Question 1)
When I try to run demo I am getting the following error message
> library(ROCR)
> demo(ROCR)
> if(dev.cur() <= 1) .... [TRUNCATED]
Error in get(getOption("device")) : wrong first argument
When I issue the command
> dev.cur()
it
2009 Sep 24
3
pipe data from plot(). was: ROCR.plot methods, cross validation averaging
All,
I'm trying again with a slightly more generic version of my first question. I can extract the
plotted values from hist(), boxplot(), and even plot.randomForest(). Observe:
# get some data
dat <- rnorm(100)
# grab histogram data
hdat <- hist(dat)
hdat #provides details of the hist output
#grab boxplot data
bdat <- boxplot(dat)
bdat #provides details of the boxplot
2012 Feb 09
2
ROCR crashes for simple recall plot
I'm trying to use ROCR to create a simple cutoff vs recall plot
(recall at p) on the example ROCR.simple dataset:
library(ROCR)
data(ROCR.simple)
pred <- prediction(ROCR.simple$predictions, ROCR.simple$labels)
perf <- performance(pred, "rec")
plot(perf)
But R crashes on me on the last line.
I'm using R 2.14.1, ROCR 1.0-4. ?Any ideas? Thanks in advance.
--
Yang Zhang
2008 May 22
1
Extracting slots from ROCR prediction objects
Hi,
I have an object from the prediction function from the ROCR package and I would like to extract one of the slots from the object, for example the cutoffs slot. However the usual techniques ($, [["name"]]) of subsetting don't work. How can I assess the lists in the slots?
Here is an example of what I am working with:
library(ROCR)
data(ROCR.simple)
pred <-
2012 Nov 22
2
ROCR package not installing
I have tried installing the package (ROCR) with this command:
Install.packages(ROCR)
And with this command on the command line
R CMD INSTALL ROCR_1.0-4.tar.gz
But both times I get exactly the same error shown below, I don't understand
what is wrong, is this an error in the package code?
Thank you
Philip
probinson@bioinform08:/tmp/RtmpO0rFbx/downloaded_packages$ R CMD
2006 Nov 24
1
How to find AUC in SVM (kernlab package)
Dear all,
I was wondering if someone can help me. I am learning SVM for
classification in my research with kernlab package. I want to know about
classification performance using Area Under Curve (AUC). I know ROCR
package can do this job but I found all example in ROCR package have
include prediction, for example, ROCR.hiv {ROCR}. My problem is how to
produce prediction in SVM and to find
2009 Jul 25
4
ROCR package question
I use ROCR to plot multiple runs' performance. Using the sample code
as example:
# plot ROC curves for several cross-validation runs (dotted
# in grey), overlaid by the vertical average curve and boxplots
# showing the vertical spread around the average.
data(ROCR.xval)
pred <- prediction(ROCR.xval$predictions, ROCR.xval$labels)
perf <- performance(pred,"tpr","fpr")
2012 Dec 19
2
pROC and ROCR give different values for AUC
Packages pROC and ROCR both calculate/approximate the Area Under (Receiver Operator) Curve. However the results are different.
I am computing a new variable as a predictor for a label. The new variable is a (non-linear) function of a set of input values, and I'm checking how different parameter settings contribute to prediction. All my settings are predictive, but some are better.
The AUC i
2009 Jul 23
1
ROCR - confidence interval for Sens and Spec
Dear List,
I am new to ROC analysis and the package ROCR. I want to compute the confidence intervals of sensitivity and specificity for a given cutoff value. I have used the following to calculate sensitivity and specificity:
data(ROCR.simple)
pred <- prediction(ROCR.simple$predictions, ROCR.simple$labels)
se.sp <- function (cutoff, performance) {
sens <-
2009 Mar 27
1
ROCR package finding maximum accuracy and optimal cutoff point
If we use the ROCR package to find the accuracy of a classifier
pred <- prediction(svm.pred, testset[,2])
perf.acc <- performance(pred,"acc")
Do we?find the maximum accuracy?as follows?(is there a simplier way?):
> max(perf.acc at x.values[[1]])
Then to find the cutoff point that maximizes the accuracy?do we do the
following?(is there a simpler way):
> cutoff.list <-
2012 Jun 08
1
Problems when install ROCR
I meet lots of problem when installing the package ROCR, do you have meet such problems?
1, biocLite("ROCR")
2, biocLite("gplots")
3, biocLite("Rgraphviz")
4, sudo apt-get install graphviz
oh, no, unlimited question, what's wrong with R in ROCR or gplots or et al
Error : object ‘nobs’ is not exported by 'namespace:gdata'
installation of package
2010 Aug 17
1
ROCR predictions
Hi everybody,
I am having a problem building a ROC curve with my data using the ROCR
package.
I have 10 lists of proteins such as attached (proteinlist.xls). each of the
lists was calculated with a different p-value.
The goal is to find the optimal p-value for the highest number of true
positives as well as lowaest number of false positives.
As far as I understood the explanations from the
2010 Feb 23
1
installing ROCR/gplots packages blows up memory
When I try to install the ROCR package (which requires gplots) on
Ubuntu 9.10 (Xubuntu Karmic Koala) 64-bit on R version 2.9.2
(2009-08-24), it eats up all my RAM (2GB) and swap (4GB) and keeps
allocating more memory until Linux's out of memory (OOM) killer kills
the perl process. This problem is special to Ubuntu because I can
install other packages (such as party) on this Ubuntu system, and
2012 Jul 13
1
ROC curves with ROCR
Hi,
I don't really understand how ROCR works. Here's another example with a
randomforest model: I have the training dataset(bank_training) and testing
dataset(bank_testing) and I ran a randomForest as below:
bankrf<-randomForest(y~., bank_training, mtry=4, ntree=2,
keep.forest=TRUE,importance=TRUE)
bankrf.pred<-predict(bankrf, bank_testing)
1999 Jul 06
0
Force Group and NFS mounted dir problems
Hi!
I hope you can assist me with this one.
We are using version Samba 2.0.3 and are having troubles making the "force
group" config option work as expected. To make matters more interesting the
file system being samba-shared is mounted from another unix server.
To explain:
Machine "marvin" (Solaris 2.7) exports /mnt/anthias using (/etc/dfs/dfstab):
share -F nfs -o
2009 Mar 19
1
Prediction-class ROCR
Hi,
I'm involved in a bioinformatics project at my university, and we're doing a comparison paper between some methods of classification of nc-RNA. I've been encharged of ploting the ROC curves' graphs. But I'm new on working with R and I'm having some difficulty with the prediction-class. I don't get where the values of ROCR.simple$predictions, for example, came from
2011 Apr 06
3
ROCR - best sensitivity/specificity tradeoff?
Hi,
My questions concerns the ROCR package and I hope somebody here on the list can help - or point me to some better place.
When evaluating a model's performane, like this:
pred1 <- predict(model, ..., type="response")
pred2 <- prediction(pred1, binary_classifier_vector)
perf <- performance(pred, "sens", "spec")
(Where "prediction" and
2011 Apr 15
2
prediction error in ROCR package when sampled y consists of only one class
Dear R users,
Hi. I am using prediction function in ROCR package.
y consists of two classes 0 and 1.
However, since I am using cross-validation, a sampled small number of
y may consist of only one class
>y
[1] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
In this case, prediction function gives an error:
Error in prediction(predic, y) : Number of classes is not equal to 2.
ROCR currently supports