search for: misclassifi

Dear experts, I'm new in R and trying to learn by writing a version of the Perceptron Algorithm. How can I tell in the code below to stop the iteration when the condition in the "for loop" is not satisfied for all training examples? Thanks in advance for your help! ## Generate a linearly separable data set in R2 sample <- as.data.frame(cbind(runif(n=100),runif(n=100)))

...developed classifications models to help identify problem accounts. The logic is this, if the model classifies the record as including variable X and it turns out that record does not have X then it should be reviewed(ie i need the row number/ID saved to a database). Generally i want to look at the misclassified records. This is a little hack i know, anyone got a better idea please let me know. Here is an example library(rpart) # grow tree fit <- rpart(Kyphosis ~ Age + Number + Start, method="class", data=kyphosis) #predict prediction<-predict(fit, kyphosis) #misclassification index...

Hi, I have a bunch of data points x from two classes A & B, and I'm creating a classifier. So I have a function f(x) which estimates the probability that x is in class A. (I have an equal number of examples of each, so p(class) = 0.5.) One way of seeing how well this does is to compute the error rate on the test set, i.e. if f(x)>0.5 call it A, and see how many times I

...ROC function in package 'nonbinROC'. The documentation says that the values of the penalty matrix code the penalty function L[i,j] in which 0 <= L[i,j] <= 1 for j > i. It gives an example that if we have an ordered response with 4 categories, then we might wish to penalise larger misclassifications more - so there is (for example) 0 penalty for correct classifications, 0.25 penalty for misclassifying by one category, 0.5 penalty for misclassifying by two categories and 1.0 penalty for misclassifying by 3 categories. I wanted to use this sort of penalty - but with equal distances betwee...

Hello I want to build a classification tree for a binary response variable while the condition for the final tree should be : The total misclassification for each group (zero or one) will be less then 10% . for example: if I have in the root 100 observations, 90 from group 0 and 10 from group 1, I want that in the final tree a maximum of 9 and 1 observations out of group 0 and 1, respectively, will be misclassified. Does anyone know what code...

I use sieve-filter for postprocessing misclassified mail. For false positives I use the following script: require [ "variables", "include", "fileinto" ]; global [ "FORCENOSPAM", "ext", "ext1" ]; set "FORCENOSPAM" "YES"; fileinto "JUNK-PRENOUCE"; if...

Dear friends, I have several sets of points in a transformed environmental space. Each set of points can be represented as a cloud in the environmental space. This space is spanned by n coordinates, corresponding to the first n PCs of 36 PCs of some environmental variables (12 monthly minimum temperatures, 12 monthly maximum temperature, 12 monthly precipitations). I would like to calculate

Hello, When I plot or look at the error rate vector for a random forest (rf$err.rate) it looks like a descending function except for a few first points of the vector with error rates values lower(sometimes much lower) than the general level of error rates for a forest with such number of trees when the error rates stop descending. Does it mean that there is a tree(s) (that is built the first in

Op 8/13/2015 om 4:33 PM schreef Jost Krieger: > I use sieve-filter for postprocessing misclassified mail. > For false positives I use the following script: > > require [ "variables", "include", "fileinto" ]; > > global [ "FORCENOSPAM", "ext", "ext1" ]; > > set "FORCENOSPAM" "YES"; > >...

Now available on CRAN. Package: mspath Title: Multi-state Path-Dependent Models in Discrete Time Description: Functions for fitting path-dependent (non-Markov) multi-state models to categorical processes observed at arbitrary times, optionally with misclassified responses, and covariates on transition or misclassification rates. Uses discrete-time approximation. Based on the Jackson's msm package v 0.3.1, with an interface as compatible as possible. _______________________________________________ R-packages mailing list R-packages at r-projec...

Hello, I need to draw a vertical line on my plot, the uncertainty segment (which is a vertical segment on every point of my plot so I can have an idea about the probability that a point is misclassified.... clustering problem.....) I remember I have done it a long time ago in Splus using a function called "segment" to which we give the extrem point of the segment , I didn't find such function in R, does it exist in R and if yes what is the name please? Thank you so much Halim...

Hello again I've looked through ?rpart, Atkinson & Therneau (1997), Chap 10 of Venables and Ripley, Breman et al., and the r hgelp archives but haven't seen the answer to these two questions 1) How does rpart deal with asymmetric loss matrices? Breiman et al. suggest some possibilities, but, of course, do not say how rpart does it. 2) In the loss matrix, which direction (column or

Dear R users, Usually the variance-inflation factor, which is based on R^2, is used as a measure for multicollinearity. But, in contrast to OLS regression there is no robust R^2 available for MM-regressions in R. Do you know if an equivalent or an alternative nmeasure of multicollinearity is available for MM-regression in R? With best regards, Carsten Colombier Dr. Carsten Colombier Economist

...(from package kernlab) for a classification task (with RBF-Kernel). My data has dozens of variables and I need to identify which variables contribute most to the classification performance. What I did so far is comparing the classification performance (measured for example with the proportion of misclassified cases) of different sets of variables with cross-validation. Unfortunately this is very slow and doing, for example, a backward variable selection procedure will take half a day with my data. This raises 3 interrelated questions: Does someone know an alternative way to perform variable selectio...

Now available on CRAN. Package: mspath Title: Multi-state Path-Dependent Models in Discrete Time Description: Functions for fitting path-dependent (non-Markov) multi-state models to categorical processes observed at arbitrary times, optionally with misclassified responses, and covariates on transition or misclassification rates. Uses discrete-time approximation. Based on the Jackson's msm package v 0.3.1, with an interface as compatible as possible. _______________________________________________ R-packages mailing list R-packages at r-projec...

Hi, I am trying to model credit risk data using decision trees. Since the number of defaulters is less compared to non-defaulters (defaulters around 10%), we have the class imbalance problem. Consequently, the confusion matrix shows that the number of misclassified non-defaulters is large. Classifying a defaulter as non-defaulter is more expensive. How does one include this information (penalty matrix) into rpart function? Thanks and regards, Dr S Muralidharan Chief Scientist, Tata Consultancy Services 17, Cathedral Road, Chennai - 600 086,Tamil Nadu Ind...

...s the change in sodium concentration during the experiment, and as expected due to the character of the treatment this is larger in all the treated animals (n=10) as compared to the controls (n=6). This is also the case for 1000 replicated sets under the more complex model while quite a few of misclassifications (control animal change > treated animal change) occurs under the less complex model. To understand (a bit at least) what goes on I have tried to see the observed data under random group assignment in the hope to be able to compare directly and formally the results from the replicates...

I (finally) moved over to Maildir storage here and would like to implement some "scripts" to manage taking actions on emails manually identified as misclassified as spam/ham. After reading through the Dovecot 2 description of how it works to try to see how it interacts with other processes changing the files. I'm concerned that I would be corrupting the message indexes if I just go hog-wild and run the scripts on the filesystem, rather than throug...

...'s one minor twist: the "learn as ham" folder will need to be write-only for users. (I'll either create a fake user with read access to extract the mail for sa-learn, or do some local filesystem access, etc. A problem for a future day.) The issue is that some of the mail being misclassified might contain sensitive information. So users should be able to copy messages into that folder, but not list or read other messages. (Yes, they will be removed from the folder by the future sa-learn script, don't worry.) I can get normal operation with the ACL plugin and a global ACL file:...

Greetings list, We have an issue with call quality at 2 sites where the users (4 Elmeg IP290s at one site, 2 SPA942s at the other) do not have an asterisk box on-site. Each site has an 8mb down/448k up ADSL connection and the phones connect via SIP to an asterisk box in a datacentre using g729. The asterisk box in the datacentre connects to our other asterisk boxes providing pstn connectivity