Regression
How to do a linear regression in R
Now that we have the model, we can visualize it by overlaying it over the original training data. To do this, we'll extract the slope and intercept from the model object and then plot the line over the training data using ggplot2. As you look at this, remember what we're actually doing here. We took a training dataset and used lm() to compute the best fit line through those training data points. Ultimately, this yields a slope and intercept that enable us to draw a line of the form .
Python Regression Analysis: Statistics & Machine Learning
This hands-on, regression-analysis bootcamp will help you master practical statistical modeling and machine learning in Python. Regression analysis is one of the central aspects of both statistical and machine learning based analysis. This course will teach you regression analysis for both statistical data analysis and machine learning in Python in a practical hands-on manner. It explores the relevant concepts in a practical manner from basic to expert level. This course can help you achieve better grades, give you new analysis tools for your academic career, implement your knowledge in a work setting & make business forecasting related decisions...All of this while exploring the wisdom of an Oxford and Cambridge educated researcher. Most statistics and machine learning courses and books only touch upon the basic aspects of regression analysis.
Dimension-Free Average Treatment Effect Inference with Deep Neural Networks
Du, Xinze, Fan, Yingying, Lv, Jinchi, Sun, Tianshu, Vossler, Patrick
This paper investigates the estimation and inference of the average treatment effect (ATE) using deep neural networks (DNNs) in the potential outcomes framework. Under some regularity conditions, the observed response can be formulated as the response of a mean regression problem with both the confounding variables and the treatment indicator as the independent variables. Using such formulation, we investigate two methods for ATE estimation and inference based on the estimated mean regression function via DNN regression using a specific network architecture. We show that both DNN estimates of ATE are consistent with dimension-free consistency rates under some assumptions on the underlying true mean regression model. Our model assumptions accommodate the potentially complicated dependence structure of the observed response on the covariates, including latent factors and nonlinear interactions between the treatment indicator and confounding variables. We also establish the asymptotic normality of our estimators based on the idea of sample splitting, ensuring precise inference and uncertainty quantification. Simulation studies and real data application justify our theoretical findings and support our DNN estimation and inference methods.
A Novel Gaussian Process Based Ground Segmentation Algorithm with Local-Smoothness Estimation
Mehrabi, Pouria, Taghirad, Hamid D.
Autonomous Land Vehicles (ALV) shall efficiently recognize the ground in unknown environments. A novel $\mathcal{GP}$-based method is proposed for the ground segmentation task in rough driving scenarios. A non-stationary covariance function is utilized as the kernel for the $\mathcal{GP}$. The ground surface behavior is assumed to only demonstrate local-smoothness. Thus, point estimates of the kernel's length-scales are obtained. Thus, two Gaussian processes are introduced to separately model the observation and local characteristics of the data. While, the \textit{observation process} is used to model the ground, the \textit{latent process} is put on length-scale values to estimate point values of length-scales at each input location. Input locations for this latent process are chosen in a physically-motivated procedure to represent an intuition about ground condition. Furthermore, an intuitive guess of length-scale value is represented by assuming the existence of hypothetical surfaces in the environment that every bunch of data points may be assumed to be resulted from measurements from this surfaces. Bayesian inference is implemented using \textit{maximum a Posteriori} criterion. The log-marginal likelihood function is assumed to be a multi-task objective function, to represent a whole-frame unbiased view of the ground at each frame. Simulation results shows the effectiveness of the proposed method even in an uneven, rough scene which outperforms similar Gaussian process based ground segmentation methods. While adjacent segments do not have similar ground structure in an uneven scene, the proposed method gives an efficient ground estimation based on a whole-frame viewpoint instead of just estimating segment-wise probable ground surfaces.
Bayesian Modelling of Multivalued Power Curves from an Operational Wind Farm
Bull, L. A., Gardner, P. A., Rogers, T. J., Dervilis, N., Cross, E. J., Papatheou, E., Maguire, A. E., Campos, C., Worden, K.
Power curves capture the relationship between wind speed and output power for a specific wind turbine. Accurate regression models of this function prove useful in monitoring, maintenance, design, and planning. In practice, however, the measurements do not always correspond to the ideal curve: power curtailments will appear as (additional) functional components. Such multivalued relationships cannot be modelled by conventional regression, and the associated data are usually removed during pre-processing. The current work suggests an alternative method to infer multivalued relationships in curtailed power data. Using a population-based approach, an overlapping mixture of probabilistic regression models is applied to signals recorded from turbines within an operational wind farm. The model is shown to provide an accurate representation of practical power data across the population.
The Essence of Logistic Regression
Logistic Regression aim is to assign a probability to an event occuring or a sample belonging to a certain class given some features. This is analogous to a boolean valued output. An example problem is determining whether a student passes an exam or not. Let's assign a pass (success) as 1 and a fail as 0. Now, let's assume we know how long they have spent studying for their exam, call this X_1, and whether they passed their previous exam, X_2. Where Y is the target, that should take values between 0 and 1, and the ฮฒ values are the unknown coefficients that we need to compute to fit the model.
Automated Benchmark-Driven Design and Explanation of Hyperparameter Optimizers
Moosbauer, Julia, Binder, Martin, Schneider, Lennart, Pfisterer, Florian, Becker, Marc, Lang, Michel, Kotthoff, Lars, Bischl, Bernd
Automated hyperparameter optimization (HPO) has gained great popularity and is an important ingredient of most automated machine learning frameworks. The process of designing HPO algorithms, however, is still an unsystematic and manual process: Limitations of prior work are identified and the improvements proposed are -- even though guided by expert knowledge -- still somewhat arbitrary. This rarely allows for gaining a holistic understanding of which algorithmic components are driving performance, and carries the risk of overlooking good algorithmic design choices. We present a principled approach to automated benchmark-driven algorithm design applied to multifidelity HPO (MF-HPO): First, we formalize a rich space of MF-HPO candidates that includes, but is not limited to common HPO algorithms, and then present a configurable framework covering this space. To find the best candidate automatically and systematically, we follow a programming-by-optimization approach and search over the space of algorithm candidates via Bayesian optimization. We challenge whether the found design choices are necessary or could be replaced by more naive and simpler ones by performing an ablation analysis. We observe that using a relatively simple configuration, in some ways simpler than established methods, performs very well as long as some critical configuration parameters have the right value.
From Kepler to Newton: Explainable AI for Science Discovery
Li, Zelong, Ji, Jianchao, Zhang, Yongfeng
The Observation--Hypothesis--Prediction--Experimentation loop paradigm for scientific research has been practiced by researchers for years towards scientific discoveries. However, with data explosion in both mega-scale and milli-scale scientific research, it has been sometimes very difficult to manually analyze the data and propose new hypothesis to drive the cycle for scientific discovery. In this paper, we discuss the role of Explainable AI in scientific discovery process by demonstrating an Explainable AI-based paradigm for science discovery. The key is to use Explainable AI to help derive data or model interpretations as well as scientific discoveries or insights. We show how computational and data-intensive methodology -- together with experimental and theoretical methodology -- can be seamlessly integrated for scientific research. To demonstrate the AI-based science discovery process, and to pay our respect to some of the greatest minds in human history, we show how Kepler's laws of planetary motion and the Newton's law of universal gravitation can be rediscovered by (Explainable) AI based on Tycho Brahe's astronomical observation data, whose works were leading the scientific revolution in the 16-17th century. This work also highlights the important role of Explainable AI (as compared to Blackbox AI) in science discovery to help humans prevent or better prepare for the possible technological singularity that may happen in the future.
How Can Regression Models Help Us in Making Better Predictions?
You'd probably enjoy being able to make predictions about something important to you, right? In this post, I'll show you how to use regression information to analyze predictions and see if they're both unbiased and accurate. In these best data analytics courses online, you will have a better understanding of data analytics. Predictions can be made using regression equations. After fitting a model, regression equations are an important part of the statistical output.
The 'How' Behind Machine Learning: An Overview of ML Algorithms
Now, we get into the more technical part of this article: ML Algorithms. I'll include a TL;DR, although I encourage you to browse through the different algorithms. I'll also include a really helpful AI course video that I personally used to learn and write this article at the very end. Without further wait, let's start going in-depth on the different algorithms used in machine learning. Linear regression is a supervised learning model used for regression that predicts a dependent variable (Y) based on the independent variable(s) (X) by fitting a line linearly.