search for: auc1

Displaying 8 results from an estimated 8 matches for "auc1".

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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( perf1, type="l",col=1 ) auc1 <- performance(pred1,"auc") auc1 <- auc1@y.values[[2]] " 2. I have to compare two models that have ver...
2010 Oct 22
2
Random Forest AUC
...),] iris$Species <- factor(iris$Species) fit <- glm(Species~.,iris,family=binomial) train.predict <- predict(fit,newdata = iris,type="response") library(ROCR) plot(performance(prediction(train.predict,iris$Species),"tpr","fpr"),col = "red") auc1 <- performance(prediction(train.predict,iris$Species),"auc")@y.values[[1]] legend("bottomright",legend=c(paste("Logistic Regression (AUC=",formatC(auc1,digits=4,format="f"),")",sep="")), col=c("red"), lty=1) library(rand...
2008 Jun 12
1
About Mcneil Hanley test for a portion of AUC!
...the function cROC. I can only find the value of "r" for the whole AUC's . > seROC<-function(AUC,na,nn){ > a<-AUC > q1<-a/(2-a) > q2<-(2*a^2)/(1+a) > se<-sqrt((a*(1-a)+(na-1)*(q1-a^2)+(nn-1)*(q2-a^2))/(nn*na)) > se > } > > cROC<-function(AUC1,na1,nn1,AUC2,na2,nn2,r){ > se1<-seROC(AUC1,na1,nn1) > se2<-seROC(AUC2,na2,nn2) > > sed<-sqrt(se1^2+se2^2-2*r*se1*se2) > zad<-(AUC1-AUC2)/sed > p<-dnorm(zad) > a<-list(zad,p) > a Could somebody kindly suggest me how to calculate the value of "r" o...
2006 Mar 15
1
How to compare areas under ROC curves calculated with ROCR package
...e the AUC. I used the following program I found on R-help archives : From: Bernardo Rangel Tura Date: Thu 16 Dec 2004 - 07:30:37 EST seROC<-function(AUC,na,nn){ a<-AUC q1<-a/(2-a) q2<-(2*a^2)/(1+a) se<-sqrt((a*(1-a)+(na-1)*(q1-a^2)+(nn-1)*(q2-a^2))/(nn*na)) se } cROC<-function(AUC1,na1,nn1,AUC2,na2,nn2,r){ se1<-seROC(AUC1,na1,nn1) se2<-seROC(AUC2,na2,nn2) sed<-sqrt(se1^2+se2^2-2*r*se1*se2) zad<-(AUC1-AUC2)/sed p<-dnorm(zad) a<-list(zad,p) a } The author of this script says: "The first function (seROC) calculate the standard error of ROC curve, the se...
2006 Mar 20
1
How to compare areas under ROC curves calculated with ROC R package
...e the AUC. I used the following program I found on R-help archives : From: Bernardo Rangel Tura Date: Thu 16 Dec 2004 - 07:30:37 EST seROC<-function(AUC,na,nn){ a<-AUC q1<-a/(2-a) q2<-(2*a^2)/(1+a) se<-sqrt((a*(1-a)+(na-1)*(q1-a^2)+(nn-1)*(q2-a^2))/(nn*na)) se } cROC<-function(AUC1,na1,nn1,AUC2,na2,nn2,r){ se1<-seROC(AUC1,na1,nn1) se2<-seROC(AUC2,na2,nn2) sed<-sqrt(se1^2+se2^2-2*r*se1*se2) zad<-(AUC1-AUC2)/sed p<-dnorm(zad) a<-list(zad,p) a } The author of this script says: "The first function (seROC) calculate the standard error of ROC curve, the se...
2009 Oct 28
1
need help explain the routine input parameters for seROC and cROC found in the R archive
...in advance. > From: Bernardo Rangel Tura > Date: Thu 16 Dec 2004 - 07:30:37 EST > > seROC<-function(AUC,na,nn){ > a<-AUC > q1<-a/(2-a) > q2<-(2*a^2)/(1+a) > se<-sqrt((a*(1-a)+(na-1)*(q1-a^2)+(nn-1)*(q2-a^2))/(nn*na)) > se > } > > cROC<-function(AUC1,na1,nn1,AUC2,na2,nn2,r){ > se1<-seROC(AUC1,na1,nn1) > se2<-seROC(AUC2,na2,nn2) > > sed<-sqrt(se1^2+se2^2-2*r*se1*se2) > zad<-(AUC1-AUC2)/sed > p<-dnorm(zad) > a<-list(zad,p) > a > } > -- Waverley @ Palo Alto
2004 Dec 15
3
(no subject)
Dear R-helper, I would like to compare the AUC of two logistic regression models (same population). Is it possible with R ? Thank you Roman Rouzier [[alternative HTML version deleted]]
2011 Dec 22
0
randomforest and AUC using 10 fold CV - Plotting results
...(factor(Species) ~ ., data=iris, ntree=50) train.predict <- predict(fit,iris,type="prob")[,2] plot(performance(prediction(train.predict,factor(iris$Species)),"tpr","fpr"),col = "red") #As expected AUC is 1 because we are using the same dataset to validate auc1 <- performance(prediction(train.predict,factor(iris$Species)),"auc")@y.values[[1]] legend("bottomright",legend=c(paste("Random Forests (AUC=",formatC(auc1,digits=4,format="f"),")",sep="")), col=c("red"), lty...