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You might be wondering what motivates me spending countless weekend hours on the MOB package. The answer is plain and simple. It is users that are driving the development work. After I published the wts_bin() function last week showing the impact of two-value weights on the monotonic binning outcome (... [Read more...]

After working on the MOB package, I received requests from multiple users if I can write a binning function that takes the weighting scheme into consideration. It is a legitimate request from the practical standpoint. For instance, in the development of fraud detection models, we often would sample down non-fraud ... [Read more...]

After wrapping up the function batch_woe() today with the purpose to allow users to apply WoE transformations to many independent variables simultaneously, I have completed the development of major functions in the MOB package that can be usable for the model development in a production setting. The function batch_... [Read more...]

In my GitHub repository (https://github.com/statcompute/MonotonicBinning), multiple R functions have been developed to implement the monotonic binning by using either iterative discretization or isotonic regression. With these functions, we can run the monotonic binning for one independent variable at a time. However, in a real-world production environment, ... [Read more...]

In addition to monotonic binning algorithms introduced in my previous post (https://statcompute.wordpress.com/2019/03/10/a-summary-of-my-home-brew-binning-algorithms-for-scorecard-development), two more functions based on Generalized Boosted Regression Models have been added to my GitHub repository, gbm_bin() and gbmcv_bin(). The function gbm_bin() estimates a GBM model without the cross validation and ... [Read more...]

In my previous post (https://statcompute.wordpress.com/2019/03/10/a-summary-of-my-home-brew-binning-algorithms-for-scorecard-development), I’ve shown different monotonic binning algorithm that I developed over time. However, these binning functions are all useless without a deployment vehicle in production. During the weekend, I finally had time to draft a R function (https://github.com/statcompute/... [Read more...]

Thus far, I have published four different monotonic binning algorithms for the scorecard development and think that it might be a right timing to do a quick summary. R functions for these binning algorithms are also available on https://github.com/statcompute/MonotonicBinning. The first one was posted back in 2017 (... [Read more...]

In past several weeks, I spent a tremendous amount of time on reading literature about automatic parameter tuning in the context of Machine Learning (ML), most of which can be classified into two major categories, e.g. search and optimization. Searching mechanisms, such as grid search, random search, and Sobol ... [Read more...]

In the post https://statcompute.wordpress.com/2017/09/03/variable-selection-with-elastic-net, it was shown how to optimize hyper-parameters, namely alpha and gamma, of the glmnet by using the built-in cv.glmnet() function. However, following a similar logic of hyper-parameter optimization shown in the post https://statcompute.wordpress.com/2019/02/10/direct-optimization-of-hyper-parameter, we can directly optimize ... [Read more...]

In the previous post (https://statcompute.wordpress.com/2019/02/03/sobol-sequence-vs-uniform-random-in-hyper-parameter-optimization), it is shown how to identify the optimal hyper-parameter in a General Regression Neural Network by using the Sobol sequence and the uniform random generator respectively through the N-fold cross validation. While the Sobol sequence yields a slightly better performance, outcomes ... [Read more...]

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In the previous post https://statcompute.wordpress.com/2018/07/29/co-integration-and-pairs-trading, it was shown how to identify two co-integrated stocks in the pair trade. In the example below, I will show how to form a mean reverting portfolio with three or more stocks, e.g. stocks with co-integration, and also how to ... [Read more...]

In the scorecard development, the area under ROC curve, also known as AUC, has been widely used to measure the performance of a risk scorecard. Given everything else equal, the scorecard with a higher AUC is considered more predictive than the one with a lower AUC. However, little attention has ... [Read more...]

In a project of developing PPNR balance projection models, I tried to use the Phillips-Ouliaris (PO) test to investigate the cointegration between the historical balance and a set of macro-economic variables and noticed that implementation routines of PO test in various R packages, e.g. urca and tseries, would give ... [Read more...]

In all monotonic algorithms that I posted before, I heavily relied on the smbinning::smbinning.custom() function contributed by Herman Jopia as the utility function generating the binning output and therefore feel deeply indebted to his excellent work. However, the availability of smbinning::smbinning.custom() function shouldn’t become my ... [Read more...]

In the post (https://statcompute.wordpress.com/2018/11/23/more-robust-monotonic-binning-based-on-isotonic-regression), a more robust version of monotonic binning based on the isotonic regression was introduced. Nonetheless, due to the loss of granularity, the predictability has been somewhat compromised, which is a typical dilemma in the data science. On one hand, we don’t ... [Read more...]

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In the post (https://statcompute.wordpress.com/2018/11/17/growing-list-vs-growing-queue), it is shown how to grow a list or a list-like queue based upon a dataframe. In the example, the code snippet was heavily relied on the FOR loop to do the assignment item by item, which I can’t help thinking ... [Read more...]

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