Displaying 20 results from an estimated 4000 matches similar to: "[Classification] lifting score in R"
2007 Jul 26
5
ROC curve in R
Hi,
I need to build ROC curve in R, can you please provide data steps / code
or guide me through it.
Thanks and Regards
Rithesh M Mohan
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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$predictions, for example, came from
2007 Nov 21
1
Calculating AUC from ROCR
Dear R-helper,
I am working with ROCR of Tobias Sing et. al. to compare the performances of
logistic and nnet models on a binary response.
I had the performance plots, but I have problem finding out other
performance statistics (eg. MSE/ASE, AUC). Any help on this?
Thanks
Ilham
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2009 May 12
1
ROCR: auc and logarithm plot
Hi,
I am quite new to R and I have two questions regarding ROCR.
1. I have tried to understand how to extract area-under-curve value by looking at the ROCR document and googling. Still I am not sure if I am doing the right thing. Here is my code, is "auc1" the auc value?
"
pred1 <- prediction(resp1,label1)
perf1 <- performance(pred1,"tpr","fpr")
plot(
2009 Aug 21
1
ROC curve and gains/lift chart
What is the difference between ROC curve and gains/lift chart?
how to do them in R?
Thanks.
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2008 May 22
1
Extracting slots from ROCR prediction objects
Hi,
I have an object from the prediction function from the ROCR package and I would like to extract one of the slots from the object, for example the cutoffs slot. However the usual techniques ($, [["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 <-
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 Jan 17
2
net classification improvement?
Greetings,
I have generated several ROC curves and would like to compare the AUCs.
The data are cross sectional and the outcomes are binary. I am testing
which of several models provide the best discrimination. Would it be most
appropriate to report AUC with 95% CI's?
I have been looking in to the "net reclassification improvement" (see
below for reference) but thus far I can only
2015 Mar 13
2
[LLVMdev] Lifting ASM to IR
Does there exist a tool that could lift a binary (assembly for some
supported target) to LLVM IR? If there isn't, does this seem like
something that would be feasible?
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2007 Oct 03
2
Speeding up simulation of mean nearest neighbor distances
I've written the function below to simulate the mean 1st through nth
nearest neighbor distances for a random spatial pattern using the
functions nndist() and runifpoint() from spatsat. It works, but runs
relatively slowly - would appreciate suggestions on how to speed up
this function. Thanks. --Dale
library(spatstat)
sim.nth.mdist <- function(nth,nsim) {
D <- matrix(ncol=nth,
2012 Mar 13
7
ROC Analysis
Hi everybody,
I have a data set with a value and a status (positive or negative case) and
I want make a ROC Analysis. So, with ROCR Package, I have got the ROC curve
(True Positive Fraction [tpf] according 1-True Negative Fraction [1-tnf]).
http://r.789695.n4.nabble.com/file/n4469203/01.png
But, now I want a new graphic which show the sum of true positive fraction
and true negative fraction
2015 Mar 13
2
[LLVMdev] Lifting ASM to IR
> On Thu, Mar 12, 2015 at 05:44:02PM -0700, Daniel Dilts wrote:
>> Does there exist a tool that could lift a binary (assembly for some
>> supported target) to LLVM IR? If there isn't, does this seem like
>> something that would be feasible?
There's plenty of variations on the idea: Revgen/S2E, Fracture, Dagger
(my own), libcpu, several closed-source ones used by
2008 Nov 20
1
classification accuracy in logistic regression
Hi all,
I'm looking for a program that will take the predicted probabilities
from a logistic regression using glm{stats}, dichotomize them according
to a threshold that I can control, and then use them to form
sensitivity, specificity, false pos and false neg rates.
Thanks in advance.
David
--
=======================================================================
David Kaplan, Ph.D.
2007 Dec 13
2
Function for AUC?
Hello
Is there an easy way, i.e. a function in a package, to calculate the
area under the curve (AUC) for drug serum levels?
Thanks for any advice
--
Armin Goralczyk, M.D.
--
Universit?tsmedizin G?ttingen
Abteilung Allgemein- und Viszeralchirurgie
Rudolf-Koch-Str. 40
39099 G?ttingen
--
Dept. of General Surgery
University of G?ttingen
G?ttingen, Germany
--
http://www.chirurgie-goettingen.de
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
2010 Jul 01
5
ROC curve in R
Hi,
i have a fairly large amount of genomic data. I have created a dataframe
which has "Reference" as one column and "Variation" as another. I want to
plot a ROC curve based on these 2 columns. I have serached the R manual but
I could not understand. Can anybody help me with the R code for plotting ROC
curve.
Thnx
ashu6886
--
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2004 Jul 26
5
installing problems repeated.tgz linux
Hi,
i try several possibilities adn looking in the archive,
but didn't getting success to install j.lindsey's usefuel "library
repeated" on my linux (suse9.0 with kernel 2.6.7,R.1.9.1)
P.S. Windows, works fine
Many thanks for help
Christian
chris at linux:/space/downs> R CMD INSTALL - l /usr/lib/R/library repeated
WARNING: invalid package '-'
WARNING:
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 <-