Regression
Machine Learning Simplified
As we discussed previously, Machine Learning refers to algorithms that are used to identify patterns within data. But what exactly do we mean by "patterns", what all can we do with ML, and what is all this jargon about "models" and "training" them. In this article, I'll try to explain all this without getting too technical, and what you, as a business-user, should know about Machine Learning. Supervised Learning implies use-cases where we have a target we're trying to predict given the data. Supervised algorithms enable us to predict the target (for example the estimated credit limit, tractor sales, if the customer will churn, or the mail category) using the input data (customer's credit history, weather and macroeconomic conditions, customer's activity on the platform, mail specifications). There are models both for Regression and Classification problems, i.e. algorithms which can solve these types of problems.
Handling Missing Data For Advanced Machine Learning
Throughout this article, you will become good at spotting, understanding, and imputing missing data. We demonstrate various imputation techniques on a real-world logistic regression task using Python. Properly handling missing data has an improving effect on inferences and predictions. This is not to be ignored. The first part of this article presents the framework for understanding missing data.
Advantages and Disadvantages of Logistic Regression
Logistic Regression is one of the supervised Machine Learning algorithms used for classification i.e. to predict discrete valued outcome. It is a statistical approach that is used to predict the outcome of a dependent variable based on observations given in the training set. Logistic Regression is one of the simplest machine learning algorithms and is easy to implement yet provides great training efficiency in some cases. Also due to these reasons, training a model with this algorithm doesn't require high computation power. The predicted parameters (trained weights) give inference about the importance of each feature.
Reducibility and Statistical-Computational Gaps from Secret Leakage
Brennan, Matthew, Bresler, Guy
Inference problems with conjectured statistical-computational gaps are ubiquitous throughout modern statistics, computer science and statistical physics. While there has been success evidencing these gaps from the failure of restricted classes of algorithms, progress towards a more traditional reduction-based approach to computational complexity in statistical inference has been limited. Existing reductions have largely been limited to inference problems with similar structure -- primarily mapping among problems representable as a sparse submatrix signal plus a noise matrix, which are similar to the common hardness assumption of planted clique. The insight in this work is that a slight generalization of the planted clique conjecture -- secret leakage planted clique -- gives rise to a variety of new average-case reduction techniques, yielding a web of reductions among problems with very different structure. Using variants of the planted clique conjecture for specific forms of secret leakage planted clique, we deduce tight statistical-computational tradeoffs for a diverse range of problems including robust sparse mean estimation, mixtures of sparse linear regressions, robust sparse linear regression, tensor PCA, variants of dense $k$-block stochastic block models, negatively correlated sparse PCA, semirandom planted dense subgraph, detection in hidden partition models and a universality principle for learning sparse mixtures. In particular, a $k$-partite hypergraph variant of the planted clique conjecture is sufficient to establish all of our computational lower bounds. Our techniques also reveal novel connections to combinatorial designs and to random matrix theory. This work gives the first evidence that an expanded set of hardness assumptions, such as for secret leakage planted clique, may be a key first step towards a more complete theory of reductions among statistical problems.
How Much Math do you need in Data Science? - KDnuggets
Can I become a data scientist with little or no math background? What essential math skills are important in data science? There are so many good packages that can be used for building predictive models or for producing data visualizations. Thanks to these packages, anyone can build a model or produce a data visualization. However, very solid background knowledge in mathematics is essential for fine-tuning your models to produce reliable models with optimal performance.
Machine Learning Regression Masterclass in Python
Artificial Intelligence (AI) revolution is here! The technology is progressing at a massive scale and is being widely adopted in the Healthcare, defense, banking, gaming, transportation and robotics industries. Machine Learning is a subfield of Artificial Intelligence that enables machines to improve at a given task with experience. Machine Learning is an extremely hot topic; the demand for experienced machine learning engineers and data scientists has been steadily growing in the past 5 years. According to a report released by Research and Markets, the global AI and machine learning technology sectors are expected to grow from $1.4B to $8.8B by 2022 and it is predicted that AI tech sector will create around 2.3 million jobs by 2020.
The flare Package for High Dimensional Linear Regression and Precision Matrix Estimation in R
Li, Xingguo, Zhao, Tuo, Yuan, Xiaoming, Liu, Han
This paper describes an R package named flare, which implements a family of new high dimensional regression methods (LAD Lasso, SQRT Lasso, $\ell_q$ Lasso, and Dantzig selector) and their extensions to sparse precision matrix estimation (TIGER and CLIME). These methods exploit different nonsmooth loss functions to gain modeling flexibility, estimation robustness, and tuning insensitiveness. The developed solver is based on the alternating direction method of multipliers (ADMM). The package flare is coded in double precision C, and called from R by a user-friendly interface. The memory usage is optimized by using the sparse matrix output. The experiments show that flare is efficient and can scale up to large problems.
Normal Equation in Linear Regression
Gradient descent is a very popular and first-order iterative optimization algorithm for finding a local minimum over a differential function. Similarly, the Normal Equation is another way of doing minimization. It does minimization without restoring to an iterative algorithm. Here, the relationship between the Number of Rooms, and the Price of the House, appears to be Linear. Here, the predictions from the Normal Equation and Linear Equation are the same.
The STATA OMNIBUS: Regression and Modelling with STATA
The STATA OMNIBUS: Regression and Modelling with STATA 4.5 (5 ratings) Course Ratings are calculated from individual students' ratings and a variety of other signals, like age of rating and reliability, to ensure that they reflect course quality fairly and accurately. Learn everything you need to know about linear regression, non-linear regression, regression modelling and STATA in one package. Learning and applying new statistical techniques can often be a daunting experience. "Easy Statistics" is designed to provide you with a compact, and easy to understand, course that focuses on the basic principles of statistical methodology. This course will focus on the concept of linear regression and non-linear regression.
Stochastic Online Optimization using Kalman Recursion
de Vilmarest, Joseph, Wintenberger, Olivier
We study the Extended Kalman Filter in constant dynamics, offering a bayesian perspective of stochastic optimization. We obtain high probability bounds on the cumulative excess risk in an unconstrained setting. In order to avoid any projection step we propose a two-phase analysis. First, for linear and logistic regressions, we prove that the algorithm enters a local phase where the estimate stays in a small region around the optimum. We provide explicit bounds with high probability on this convergence time. Second, for generalized linear regressions, we provide a martingale analysis of the excess risk in the local phase, improving existing ones in bounded stochastic optimization. The EKF appears as a parameter-free online algorithm with O(d^2) cost per iteration that optimally solves some unconstrained optimization problems.