Regression
Performance Comparison of Different Machine Learning Algorithms on the Prediction of Wind Turbine Power Generation
Eyecioglu, Onder, Hangun, Batuhan, Kayisli, Korhan, Yesilbudak, Mehmet
Over the past decade, wind energy has gained more attention in the world. However, owing to its indirectness and volatility properties, wind power penetration has increased the difficulty and complexity in dispatching and planning of electric power systems. Therefore, it is needed to make the high-precision wind power prediction in order to balance the electrical power. For this purpose, in this study, the prediction performance of linear regression, k-nearest neighbor regression and decision tree regression algorithms is compared in detail. k-nearest neighbor regression algorithm provides lower coefficient of determination values, while decision tree regression algorithm produces lower mean absolute error values. In addition, the meteorological parameters of wind speed, wind direction, barometric pressure and air temperature are evaluated in terms of their importance on the wind power parameter. The biggest importance factor is achieved by wind speed parameter. In consequence, many useful assessments are made for wind power predictions.
Stock Price Prediction Using Python & Machine Learning
In this tutorial will show you how to write a Python program that predicts the price of stocks using two different Machine Learning Algorithms, one is called a Support Vector Regression (SVR) and the other is Linear Regression. So you can start trading and making money! Actually this program is really simple and I doubt any major profit will be made from this program, but it's slightly better than guessing! In this video will show you how to write a Python program that predicts the price of stocks using two different Machine Learning Algorithms, one is called a Support Vector Regression (SVR) and the other is Linear Regression. So you can start trading and making money!
Pairwise Fairness for Ordinal Regression
Kleindessner, Matthรคus, Samadi, Samira, Zafar, Muhammad Bilal, Kenthapadi, Krishnaram, Russell, Chris
We initiate the study of fairness for ordinal regression, or ordinal classification. We adapt two fairness notions previously considered in fair ranking and propose a strategy for training a predictor that is approximately fair according to either notion. Our predictor consists of a threshold model, composed of a scoring function and a set of thresholds, and our strategy is based on a reduction to fair binary classification for learning the scoring function and local search for choosing the thresholds. We can control the extent to which we care about the accuracy vs the fairness of the predictor via a parameter. In extensive experiments we show that our strategy allows us to effectively explore the accuracy-vs-fairness trade-off and that it often compares favorably to "unfair" state-of-the-art methods for ordinal regression in that it yields predictors that are only slightly less accurate, but significantly more fair.
The $r$-value: evaluating stability with respect to distributional shifts
Gupta, Suyash, Rothenhรคusler, Dominik
Common statistical measures of uncertainty like $p$-values and confidence intervals quantify the uncertainty due to sampling, that is, the uncertainty due to not observing the full population. In practice, populations change between locations and across time. This makes it difficult to gather knowledge that transfers across data sets. We propose a measure of uncertainty that quantifies the distributional uncertainty of a statistical estimand with respect to Kullback-Liebler divergence, that is, the sensitivity of the parameter under general distributional perturbations within a Kullback-Liebler divergence ball. If the signal-to-noise ratio is small, distributional uncertainty is a monotonous transformation of the signal-to-noise ratio. In general, however, it is a different concept and corresponds to a different research question. Further, we propose measures to estimate the stability of parameters with respect to directional or variable-specific shifts. We also demonstrate how the measure of distributional uncertainty can be used to prioritize data collection for better estimation of statistical parameters under shifted distribution. We evaluate the performance of the proposed measure in simulations and real data and show that it can elucidate the distributional (in-)stability of an estimator with respect to certain shifts and give more accurate estimates of parameters under shifted distribution only requiring to collect limited information from the shifted distribution.
Universal Consistency of Decision Trees in High Dimensions
This paper shows that decision trees constructed with Classification and Regression Trees (CART) methodology are universally consistent in an additive model context, even when the number of predictor variables scales exponentially with the sample size, under certain $1$-norm sparsity constraints. The consistency is universal in the sense that there are no a priori assumptions on the distribution of the predictor variables. Amazingly, this adaptivity to (approximate or exact) sparsity is achieved with a single tree, as opposed to what might be expected for an ensemble. Finally, we show that these qualitative properties of individual trees are inherited by Breiman's random forests. Another surprise is that consistency holds even when the "mtry" tuning parameter vanishes as a fraction of the number of predictor variables, thus speeding up computation of the forest. A key step in the analysis is the establishment of an oracle inequality, which precisely characterizes the goodness-of-fit and complexity tradeoff for a misspecified model.
Building 10 Classifier Models in Machine Learning + Notebook
In the last tutorial, we completed the Data Pre-Processing step. We saw preprocessing techniques applied in transformation and variable selection, dimensionality reduction, and sampling for machine learning throughout this previous tutorial. Now we can move on to the next steps within the Data Science process, where we'll apply the rest of the model building process with various classification algorithms to understand what it is and how to use machine learning with python language. In the next moment, we will discuss the Regression algorithms. We will not go into detail about the algorithms. The purpose here will be to understand the detailed process of building the Machine Learning model, machine learning, model evaluation, and prediction scans. See The Jupyter Notebook for the concepts we'll cover on building machine learning models and my LinkedIn profile for other Data Science articles and tutorials. The metrics chosen to evaluate model performance will influence how performance is measured and compared to models created with other algorithms. We need to find a metric to measure performance between models solidly and coherently, a metric comparable to the models analyzed. Let's use the same algorithm, but with different metrics, and so compare the results.
Build a machine learning regression model using Findability Platform Predict Plus
This developer code pattern uses Findability Platform (FP) Predict Plus operator from Red Hat Marketplace to predict customer spending using historical data and demonstrates the automated process of building models. Machine learning is a large field of study that overlaps with and inherits ideas from many related fields, such as artificial intelligence. The focus of the field is learning -- that is, acquiring skills or knowledge from experience. Most commonly, this means synthesizing useful concepts from historical data. As such, there are many types of learning you may encounter as a practitioner in the field of machine learning from whole fields of study to specific techniques.
A unifying tutorial on Approximate Message Passing
Feng, Oliver Y., Venkataramanan, Ramji, Rush, Cynthia, Samworth, Richard J.
AMP algorithms have two features that make them particularly attractive. First, they can easily be tailored to take advantage of prior information on the structure of the signal, such as sparsity or other constraints. Second, under suitable assumptions on a design or data matrix, AMP theory provides precise asymptotic guarantees for statistical procedures in the high-dimensional regime where the ratio of the number of observations n to dimensions p converges to a constant (Bayati and Montanari, 2012; Donoho et al., 2013; Sur et al., 2017). More generally, AMP has been also used to obtain lower bounds on the estimation error of first-order methods (Celentano et al., 2020), and in linear regression and low rank matrix estimation, it plays a fundamental role in understanding the performance gap between information-theoretically optimal and computationally feasible estimators (Reeves and Pfister, 2019; Barbier et al., 2019; Lelarge and Miolane, 2019). In these settings, it is conjectured that AMP achieves the optimal asymptotic estimation error among all polynomial-time algorithms (cf.
How Fine-Tuning Allows for Effective Meta-Learning
Chua, Kurtland, Lei, Qi, Lee, Jason D.
Representation learning has been widely studied in the context of meta-learning, enabling rapid learning of new tasks through shared representations. Recent works such as MAML have explored using fine-tuning-based metrics, which measure the ease by which fine-tuning can achieve good performance, as proxies for obtaining representations. We present a theoretical framework for analyzing representations derived from a MAML-like algorithm, assuming the available tasks use approximately the same underlying representation. We then provide risk bounds on the best predictor found by fine-tuning via gradient descent, demonstrating that the algorithm can provably leverage the shared structure. The upper bound applies to general function classes, which we demonstrate by instantiating the guarantees of our framework in the logistic regression and neural network settings. In contrast, we establish the existence of settings where any algorithm, using a representation trained with no consideration for task-specific fine-tuning, performs as well as a learner with no access to source tasks in the worst case. This separation result underscores the benefit of fine-tuning-based methods, such as MAML, over methods with "frozen representation" objectives in few-shot learning.
Nonparametric Trace Regression in High Dimensions via Sign Series Representation
Lee, Chanwoo, Li, Lexin, Zhang, Hao Helen, Wang, Miaoyan
Learning of matrix-valued data has recently surged in a range of scientific and business applications. Trace regression is a widely used method to model effects of matrix predictors and has shown great success in matrix learning. However, nearly all existing trace regression solutions rely on two assumptions: (i) a known functional form of the conditional mean, and (ii) a global low-rank structure in the entire range of the regression function, both of which may be violated in practice. In this article, we relax these assumptions by developing a general framework for nonparametric trace regression models via structured sign series representations of high dimensional functions. The new model embraces both linear and nonlinear trace effects, and enjoys rank invariance to order-preserving transformations of the response. In the context of matrix completion, our framework leads to a substantially richer model based on what we coin as the "sign rank" of a matrix. We show that the sign series can be statistically characterized by weighted classification tasks. Based on this connection, we propose a learning reduction approach to learn the regression model via a series of classifiers, and develop a parallelable computation algorithm to implement sign series aggregations. We establish the excess risk bounds, estimation error rates, and sample complexities. Our proposal provides a broad nonparametric paradigm to many important matrix learning problems, including matrix regression, matrix completion, multi-task learning, and compressed sensing. We demonstrate the advantages of our method through simulations and two applications, one on brain connectivity study and the other on high-rank image completion.