search for: accuracy

...=1:40; 8^a %% 41 one obtains zeros which is not possible since 8 to any power is not a multiple of 41. In addition when working with numbers larger that this and with the mod operator R crashes randomly. I believe this is because R stores large integers as real numbers thus there may be lack of accuracy when applying the modulus operator and converting back to integers. So my question is this: Is it possible to increase the size of memory used for storing integers? Say from 32 bits to 512 bits (Typical size of integers in cryptography). Thank you, any help would be greatly appreciated. Ionut...

Hi all - I am trying to tune an SVM model by optimizing the cross-validation accuracy. Maximizing this value doesn't necessarily seem to minimize the number of misclassifications. Can anyone tell me how the cross-validation accuracy is defined? In the output below, for example, cross-validation accuracy is 92.2%, while the number of correctly classified samples is (1476+170)/(14...

Hi, This is my proposal to add floating point accuracy support to LLVM. The intention is that the frontend may provide metadata to signal to the backend that it may select a less accurate (i.e. more efficient) instruction to perform a given operation. This is primarily a requirement of OpenCL, which specifies that certain floating point operations may...

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...

Hi people, I need to prove the good quality of numerical accuracy of R. Anyone knows a paper or anything else comparing R to other statistical softwares in terms of numerical accuracy. I've made a long search about that but I found nothing. Please help me!! Thanx, Talita Leite ------------------------------------------------- Este e-mail foi enviado pelo W...

On 14 April 2012 20:34, Duncan Sands <baldrick at free.fr> wrote: > the verifier checks that the accuracy operand is either a floating point > number (ConstantFP) or the keyword "fast".  If "Accuracy" is zero here > then that means it wasn't ConstantFP.  Thus it must have been the keyword > "fast". I think it's assuming too much. If I write "foobar&q...

...nd 1.0 penalty for misclassifying by 3 categories. I wanted to use this sort of penalty - but with equal distances between the 4 categories (0, 1/3, 2/3, 1). But, I found that if I simply re-scale the penalty matrix, while maintaining equal distances between categories, then the estimate of overall accuracy increases. In effect I can achieve any value for accuracy - including unity - by re-scaling the penalty matrix. So, I'd like to ask what, if any are the contraints on the scaling process? Here is a working code that illustrates my difficulty:- set.seed(1); gldstd=round(runif(200)*4); gldstd[g...

Hi Renato, > I'm not sure about this: > > + if (!Accuracy) > + // If it's not a floating point number then it must be 'fast'. > + return getFastAccuracy(); > > Since you allow accuracies bigger than 1 in setFPAccuracy(), integers > should be treated as float. Or at least assert. the verifier checks that the accuracy opera...

We've made a little change that changed the output of vorbis is there a way to check the accuracy of the output against the original output? I also asked this question in the irc ... Thanks, Tal.

I was wandering if anybody ever tried to compare the classification accuracy of nnet to other (rpart, tree, bagging) models. From what I know, there is no reason to expect a significant difference in classification accuracy between these models, yet in my particular case I get about 10% error rate for tree, rpart and bagging model and 80% error rate for nnet, applied to t...

Hi, I want to use a more accurate value of exp(1).  The value given by R is 2.718282. I want a value which has more than 15 decimal places. Can anyone let me know how can I increase the accuracy level. Actually there are some large multipliers of exp(1) in my whole expression, and I want a more accurate result at the last step of my program, and for that I need to use highly accurate value of exp(1).  Can anyone help me out? Thanks. Shant [[alternative HTML version deleted]...

Hi All, We have all had to face skeptical colleagues asking if software made by volunteers could match the quality and accuracy of commercially written software. Thanks to the prompting of a recent R-help thread, I read, "R: Regulatory Compliance and Validation Issues, A Guidance Document for the Use of R in Regulated Clinical Trial Environments (http://www.r-project.org/doc/R-FDA.pdf). This is an important document, o...

...l as: model <- train(dat.dts, dat.dts.class, method='ctree', tuneLength=8, trControl=trainControl(number = 5, workers=1), metric='Kappa') I get the following puzzling numbers: mincriterion Accuracy Kappa Accuracy SD Kappa SD 0.01 0.961 0.0609 0.00151 0.0264 0.15 0.962 0.049 0.00116 0.0248 0.29 0.963 0.0405 0.00227 0.035 0.43 0.964 0.0349 0.00257 0.0247 0.57 0.964 0.0382 0.0022 0.0199...

I am using machine learning for one researching. I am using some classifiers with 5-fold CV . I would like to know how it is possible to extract the accuracy, for example, for KNN,neural networks and J48, for each one of 5-fold because when I apply CV to my classifier, I obtain the "mean accuracy" of 5-fold but each accuracy/error of each fold is not returned. Any help is welcome and grateful. Thanks in advance! Regards!! [[alternative...

...e than 2.5 ULPs of error. The first observation is that !fpmath can be extended with additional operands in the future: operands that say things like whether it is OK to assume that there are no NaNs and so forth. This patch doesn't add additional operands though. It just allows the existing accuracy operand to be the special keyword "fast" instead of a number: %z = fmul float %x, %y, !fpmath !0 ... !0 = metadata !{!metadata "fast"} This indicates that accuracy loss is acceptable (just how much is unspecified) for the sake of speed. Thanks to Chandler for pushi...

Hi R-Helpers , am working on nnet package.Multinom() has an option for finding the goodness of fit by giving the AIC value. Does nnet also gives some value to determine the accuracy. If not, can you guide me with some procedure to figure out the accuracy/goodness of fit of nnet model? Thanks in advance. -- View this message in context: http://r.789695.n4.nabble.com/Accuracy-Goodness-of-fit-of-nnet-tp3004978p3004978.html Sent from the R help mailing list archive at Nabble.com...

Hello, I have been playing around with the statistical distributions in R, and overall I think the accuracy is very good. However, it seems that for the Student's t distribution, the CDF loses accuracy when evaluated at values close to zero. For instance, I did the following in R ---------------------------------- df<-seq(1,100,by=1) z<-c(0.50003183098839799,0.50003535533895194,0.5000367552599...

...beta <- 0 ystar <- intercept+beta*x z <- rbinom(n,1,plogis(ystar)) xerr <- x + rnorm(n,0,tau) model<-glm(z ~ xerr, family=binomial(logit)) int<-coef(model)[1] slope<-coef(model)[2] pred<-predict(model) result<-ifelse(pred>.5,1,0) accuracy<-length(which(result==z))/length(z) accuracy rocpreds<-prediction(result,z) auc<-performance(rocpreds,"auc")@y.values sentiv<-performance(rocpreds,"sens")@y.values sentiv<-slot(fp,"y.values")[[1]] sentiv<-sentiv[2] sentiv...

...due to the non-linearity of the model I do not have a clue which equation to use. I am thinking of starting with a very general equation including ^3 terms and interactions between the variables however this will lead to a very long equation. Is there a way to assess the effect of each term to the accuracy of the regression model in order to discard the terms with the least importance? Something like a sensitivity analysis of the effect of each term to the accuracy regression model. I know one possible solution to my problem is simply 'trial and error' however before going down that road I wa...

...ning, and find the "e1071" pakage an excellent tool in doing data mining work! what frustrated me recently is that when I using the function "svm" and using the "cross=10" parameters, I got all the "accuracies" of the model greater than 1. Isn't that the accuracy should be smaller than 1? so I wander how, the accuracy of the cross validation is calculated, and what's the meaning of the accuracy? summary of the trained svm model as follows: > summary(model) Call: svm(formula = y ~ x, cachesize = 100, gamma = obj$best.parameters$gamma, cost = o...