new

The Support Vector Machines algorithms are well-known in the supervised learning domain. They are especially appropriate when we handle a dataset with a large number “p” of descriptors . But they are much less efficient when the number of instances “n” is very high. Indeed, a naive implementation is of complexity O(n^3) for the calculation time and O(n^2) for the storing of the values. In consequence, instead of the optimal solution, the learning algorithms often highlight the near-optimal solutions with a tractable computation time . I recently discovered the CVM (Core Vector Machine) and BVM (Ball Vector Machine) approaches. The idea of the authors is really clever: since only approximate best solutions can be highlighted, their approaches try to resolve an equivalent problem which is easier to handle - the minimum enclosing ball problem in computational geometry - to detect the support vectors. So, we have a classifier which is as efficient as those obtained by the other SVM learnin...

The R software is a fascinating project. It becomes a reference tool for the data mining process. With the R package system, we can extend its features potentially at the infinite. Almost all existing statistical / data mining techniques are available in R. But if there are many packages, there are very few projects which intend to improve the R core itself. The source code is freely available. In theory anyone can modify a part or even the whole software. Revolution Analytics proposes an improved version of R. It provides Revolution R Enterprise, it seems (according to their website) that: it improves dramatically the fastness of some calculations; it can handle very large database; it provides a visual development environment with a debugger. Unfortunately, this is a commercial tool. I could not check these features . Fortunately, a community version is available. Of course, I have downloaded the tool to study its behavior. Revolution R Community is a slightly improved version of the...

In my courses at the University, I use only free data mining tools (R, Tanagra, Sipina, Knime, Orange, etc.) and the spreadsheet applications (free or not). Sometimes, my students ask me if the commercial tools (e.g. SAS which is very popular in France) have different behavior, in terms of how to use, or for the reading of the results. I say them that some of these commercial tools are available on the computers of our department. They can learn how to use them by taking as a starting point the tutorials available on the Web. But unfortunately, especially in the French language, they are not numerous about the logistic regression. We need a didactic document with clear screenshots which show how to: (1) import a data file into a SAS bank; (2) define an analysis with the appropriate settings; (3) read and understand the results. In this tutorial, we describe the use of the SAS PROC LOGISTIC (SAS 9.3). We measure its quickness when we handle a moderate sized dataset. We compare the resul...

The connection between a data mining tool and a spreadsheet application such as Excel is a really valuable feature. We benefit from the powerful of the first one, and the popularity and the easy to use of the second one. Many people use a spreadsheet in their data preparation phase. Recently, I have presented an add-in for the connection between R and Excel. In this document, I describe a similar tool for the SAS software. SAS is a popular tool, well-known of the statisticians. But the use of SAS is not really simple for the non-specialist people. We must know the syntax of the commands before to perform a statistical analysis. With the SAS add-in for Excel, some of the SAS drawbacks are alleviated: we do not need to load and organize the dataset into a bank; we do not need to know the command syntax to perform an analysis and set the associated parameters (we use a menu and dialog boxes instead); the results are automatically incorporated in a new sheet of an Excel workbook (the post ...

New features for the principal component analysis (PCA). PRINCIPAL COMPONENT ANALYSIS. Additional outputs for the component: Scree plot and variance explained cumulative curve; PCA Correlation Matrix - Some outputs are provided for the detection of the significant factors (Kaiser-Guttman, Karlis-Saporta-Spinaki, Legendre-Legendre broken-stick test); PCA Correlation Matrix - Bartlett's sphericity test is performed and the Kaiser's measure of sampling adequacy (MSA) is calculated; PCA Correlation Matrix - The correlation matrix and the partial correlations between each pair of variables controlling for all other variables (the negative anti-image correlation) are produced. PARALLEL ANALYSIS. The component calculates the distribution of eigenvalues for a set of randomly generated data. It proceeds by randomization. It applies to the principal components analysis and te multiple correspondence analysis. A factor is considered significant if its observed eigenvalue is greater than t...

LIBSVM ( http://www.csie.ntu.edu.tw/~cjlin/libsvm/ ). Update of the LIBSVM library for support vector machine algorithms (version 3.12, April 2012) [C - SVC, Epsilon-SVR, nu - SVR]. The calculations are faster. The attributes can be normalized or not. They were automatically normalized previously. LIBCVM ( http://c2inet.sce.ntu.edu.sg/ivor/cvm.html ; version 2.2). Incorporation of the LIBCVM library. Two methods are available: CVM and BVM (Core Vector Machine and Ball Vector Machine). The dezscriptors can be normalized or not. TR-IRLS ( http://autonlab.org/autonweb/10538 ). Update of the TR-IRLS library, for the logistic regression on large dataset (large number of predictive attributes) [last available version – 2006/05/08]. The deviance is automatically provided. The display of the regression coefficients is more precise (higher number of decimals). The user can tune the learning algorithms, especially the stopping rules. SPARSE DATA FILE. Tanagra can handle sparse data file format n...

Model deployment is a crucial task of the data mining process. In the supervised learning, it can be the applying of the predictive model on new unlabeled cases. We have already described this task for various tools (e.g. Tanagra, Sipina, Spad, R). They have as common feature the use of the same tool for the model construction and the model deployment. In this tutorial, we describe a process where we do not use the same tool for the model construction and the model deployment. This is only possible if (1) the model is described in a standard format, (2) the tool which used for the deployment can handle both the database with unlabeled instances and the model. Here, we use the PMML standard description for the sharing of the model, and the PDI-CE ( Pentaho Data Integration Community Edition ) for the applying of the model on the unseen cases. We create a decision tree with various tools such as SIPINA, KNIME or RAPIDMINER; we export the model in the PMML format; then, we use PDI-CE for ...