Displaying 20 results from an estimated 2000 matches similar to: "installing ROCR/gplots packages blows up memory"
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
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
2009 Feb 27
4
Optimize for loop / find last record for each person
I want to find the last record for each person_id in a data frame
(from a SQL database) ordered by date. Is there a better way than
this for loop?
for (i in 2:length(history[,1])) {
if (history[i, "person_id"] == history[i - 1, "person_id"])
history[i, "order"] = history[i - 1, "order"] + 1 # same person
else
history[i,
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
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
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 ($, [["name"]]) of subsetting don't work. How can I assess the lists in the slots?
Here is an example of what I am working with:
library(ROCR)
data(ROCR.simple)
pred <-
2009 Sep 24
3
pipe data from plot(). was: ROCR.plot methods, cross validation averaging
All,
I'm trying again with a slightly more generic version of my first question. I can extract the
plotted values from hist(), boxplot(), and even plot.randomForest(). Observe:
# get some data
dat <- rnorm(100)
# grab histogram data
hdat <- hist(dat)
hdat #provides details of the hist output
#grab boxplot data
bdat <- boxplot(dat)
bdat #provides details of the boxplot
2012 Dec 19
2
pROC and ROCR give different values for AUC
Packages pROC and ROCR both calculate/approximate the Area Under (Receiver Operator) Curve. However the results are different.
I am computing a new variable as a predictor for a label. The new variable is a (non-linear) function of a set of input values, and I'm checking how different parameter settings contribute to prediction. All my settings are predictive, but some are better.
The AUC i
2009 Jul 23
1
ROCR - confidence interval for Sens and Spec
Dear List,
I am new to ROC analysis and the package ROCR. I want to compute the confidence intervals of sensitivity and specificity for a given cutoff value. I have used the following to calculate sensitivity and specificity:
data(ROCR.simple)
pred <- prediction(ROCR.simple$predictions, ROCR.simple$labels)
se.sp <- function (cutoff, performance) {
sens <-
2009 Jul 25
4
ROCR package question
I use ROCR to plot multiple runs' performance. Using the sample code
as example:
# plot ROC curves for several cross-validation runs (dotted
# in grey), overlaid by the vertical average curve and boxplots
# showing the vertical spread around the average.
data(ROCR.xval)
pred <- prediction(ROCR.xval$predictions, ROCR.xval$labels)
perf <- performance(pred,"tpr","fpr")
2009 Mar 27
1
ROCR package finding maximum accuracy and optimal cutoff point
If we use the ROCR package to find the accuracy of a classifier
pred <- prediction(svm.pred, testset[,2])
perf.acc <- performance(pred,"acc")
Do we?find the maximum accuracy?as follows?(is there a simplier way?):
> max(perf.acc at x.values[[1]])
Then to find the cutoff point that maximizes the accuracy?do we do the
following?(is there a simpler way):
> cutoff.list <-
2010 Aug 17
1
ROCR predictions
Hi everybody,
I am having a problem building a ROC curve with my data using the ROCR
package.
I have 10 lists of proteins such as attached (proteinlist.xls). each of the
lists was calculated with a different p-value.
The goal is to find the optimal p-value for the highest number of true
positives as well as lowaest number of false positives.
As far as I understood the explanations from the
2012 Jul 13
1
ROC curves with ROCR
Hi,
I don't really understand how ROCR works. Here's another example with a
randomforest model: I have the training dataset(bank_training) and testing
dataset(bank_testing) and I ran a randomForest as below:
bankrf<-randomForest(y~., bank_training, mtry=4, ntree=2,
keep.forest=TRUE,importance=TRUE)
bankrf.pred<-predict(bankrf, bank_testing)
2009 Mar 19
1
Prediction-class ROCR
Hi,
I'm involved in a bioinformatics project at my university, and we're doing a comparison paper between some methods of classification of nc-RNA. I've been encharged of ploting the ROC curves' graphs. But I'm new on working with R and I'm having some difficulty with the prediction-class. I don't get where the values of ROCR.simple$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
2010 Aug 17
1
ROCR data input
Hi there,
I'm having some difficulty with the ROCR package. I've installed it fine,
and the sample data works (ROCR.simple), however when I try to load my own
data it complains that there is an error in prediction as the number of
classes is not equal to 2. I read the data from a text file which contains
one column of probabilities and one column of binary 0 and 1. I then put it
into a
2007 Jun 16
1
selecting cut-off in Logistic regression using ROCR package
Hi,
I am using logistic regression to classify a binary psychometric data. using
glm() and then predict.glm() i got the predicted odds ratio of the testing
data. Next i am going to plot ROC curve for the analysis of my study.
Now what i will do:
1. first select a cut-off (say 0.4) and classify the output of predict.glm()
into {0,1} segment and then use it to draw ROC curve using ROCR package
2009 May 12
1
ROCR: auc and logarithm plot
Hi,
I am quite new to R and I have two questions regarding ROCR.
1. I have tried to understand how to extract area-under-curve value by looking at the ROCR document and googling. Still I am not sure if I am doing the right thing. Here is my code, is "auc1" the auc value?
"
pred1 <- prediction(resp1,label1)
perf1 <- performance(pred1,"tpr","fpr")
plot(
2007 Jan 24
1
Probabilities calibration error & ROCR
Hello,
I'd need to compute the calibration error of posterior class
probabilities p(y|x) estimated by using rpart as classification tree.
Namely, I train rpart on a dataset D and then use predict(...
type="prob") to estimate p(y|x).
I've found the possibility to do that in the ROCR package, but I
cannot find a link to a paper/book which explains the details of the