search for: obatin

...ue does the R utilize such that the eigen are obtained? For example, A=matrix(c(1,2,4,3),2,2) we can define the eigenvalue lamda, such as det | 1-lamda 4 | =0 | 2 3-lamda | then we can obtain the lamda=5 and -1 however, i am interesting in that how does the R to obatin lamda? By the way, how does the R also obtain the eigenvector? Basically, i must to know those definition in the R because i have to utilize eigenvalue and eigenvector to develope SVD (single value decomposition) by myself. Furthermore, i want to obtain the bi-plot about my data. Although someone...

Hi, I have a dataset that has 2 groups of samples. For each sample, then response measured is the number of success (no.success) obatined with the number of trials (no.trials). So a porportion of success (prpop.success) can be computed as no.success/no.trials. Now the objective is to test if there is a statistical significant difference in the proportion of success between the 2 groups of samples (say n1=20, n2=30). I can thin...

Hi, I initially posted this to the general R mailing list, but Bert Gunter thought this may be a mixed model issue, so suggested me to post here. I have a dataset that has 2 groups of subjects. For each subject in each group, the response measured is the number of success (no.success) obatined with the number of trials (no.trials). So a probability of success (prop.success) can be computed as no.success/no.trials for each subject in each group. The data may look like: for group 1: subject 1: 5 success, 10 trials subject 2: 3 success, 8 trials : : for group 2: subject a: 7 success,...

...defined split functions. As Terry Therneau suggested, one can use the xpred.rpart function and then summarize the matrix of the predicted values into a single "goodness" value. I need only a confirmation: set for example xval=10, if I correctly understood a single column of the matrix obatined by xpred.rpart gives (for a cp level), for each of the 10 groups of obs, the value predicted by the tree obtained with the other 9 groups. Am I right ? One more question: I want to compare the results obtained with a tree, say A, obtained with "class" method with the one, say B, I ge...