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Dear users, I'm working on binary classification problem using Support Vector Machines (SVM). My objective is to train a series of SVM models on a grid of hyperparameters and then select those that maximize the AUC based on an independent validation sample. My attempted code is shown below. It runs well on "small" data sets but when I use it on a slightly larger sample (e.g., my

...on using R for data analysis, statistical modeling, visualization, data mining, predictive analytics, statistical computing, exploratory data analysis, etc. Users from all levels are welcome. Special thanks to Revolution Analytics to help us get started and sponsor the group. Kind Regards, Leo Guelman. _______________________________________________________________________ This e-mail may be privileged and/or confidential, and the sender does not waive any related rights and obligations. Any distribution, use or copying of this e-mail or the information it contains by other than an intended rec...

Hi, Is there a way I can specify linear contrasts in glm? I'm looking for something equivalent to SAS' contrast statement. I'd like to do the following, suppose I have a categorical input with 4 levels (a,b,c,d), I'd like to test something like: (i) a+b=c+d, (ii) a=b, (iii) a=b+d, etc... Thanks in advance for your help! Leo. [[alternative HTML version deleted]]

I'm using R 2.11.1 on Win XP (32-bit) with 3 GB of RAM. My data has (only) 16.0 MB. I want to create a VCorpus object using the Corpus function in the tm package but I'm running into Memory allocation issues: "Error: cannot allocate vector of size 372 Kb". My data is stored in a csv file which I've imported with "read.csv" and then used the following to create

Dear List, I'm trying to create a formula method, allowing for a "special" character in the formula (i.e., similar to for example the gam package with the character "s" in y ~ s(x)). I've checked and it seems this is done through attr(,"specials"). However, the section of code below (as an example extracted from the gam package) gives me an error as shown at