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The Mathematics of Machine Learning

#artificialintelligence

In the last few months, I have had several people contact me about their enthusiasm for venturing into the world of data science and using Machine Learning (ML) techniques to probe statistical regularities and build impeccable data-driven products. However, I've observed that some actually lack the necessary mathematical intuition and framework to get useful results. This is the main reason I decided to write this blog post. Recently, there has been an upsurge in the availability of many easy-to-use machine and deep learning packages such as scikit-learn, Weka, Tensorflow etc. Machine Learning theory is a field that intersects statistical, probabilistic, computer science and algorithmic aspects arising from learning iteratively from data and finding hidden insights which can be used to build intelligent applications. Despite the immense possibilities of Machine and Deep Learning, a thorough mathematical understanding of many of these techniques is necessary for a good grasp of the inner workings of the algorithms and getting good results.


24 Uses of Statistical Modeling (Part I)

@machinelearnbot

Here we discuss general applications of statistical models, whether they arise from data science, operations research, engineering, machine learning or statistics. We do not discuss specific algorithms such as decision trees, logistic regression, Bayesian modeling, Markov models, data reduction or feature selection. Instead, I discuss frameworks - each one using its own types of techniques and algorithms - to solve real life problems. Most of the entries below are found in Wikipedia, and I have used a few definitions or extracts from the relevant Wikipedia articles, in addition to personal contributions. Spatial dependency is the co-variation of properties within geographic space: characteristics at proximal locations appear to be correlated, either positively or negatively. Methods for time series analyses may be divided into two classes: frequency-domain methods and time-domain methods.


Top 10 Machine Learning Algorithms

@machinelearnbot

This was the subject of a question asked on Quora: What are the top 10 data mining or machine learning algorithms? Some modern algorithms such as collaborative filtering, recommendation engine, segmentation, or attribution modeling, are missing from the lists below. Algorithms from graph theory (to find the shortest path in a graph, or to detect connected components), from operations research (the simplex, to optimize the supply chain), or from time series, are not listed either. And I could not find MCM (Markov Chain Monte Carlo) and related algorithms used to process hierarchical, spatio-temporal and other Bayesian models. For the last one I'd let you pick one of the following: For the last one I'd let you pick one of the following: My point of view is of course biased, but I would like to also add some algorithms developed or re-developed at the Data Science Central's research lab: These algorithms are described in the article What you wont learn in statistics classes.


Bayesian Body Schema Estimation using Tactile Information obtained through Coordinated Random Movements

arXiv.org Artificial Intelligence

This paper describes a computational model, called the Dirichlet process Gaussian mixture model with latent joints (DPGMM-LJ), that can find latent tree structure embedded in data distribution in an unsupervised manner. By combining DPGMM-LJ and a pre-existing body map formation method, we propose a method that enables an agent having multi-link body structure to discover its kinematic structure, i.e., body schema, from tactile information alone. The DPGMM-LJ is a probabilistic model based on Bayesian nonparametrics and an extension of Dirichlet process Gaussian mixture model (DPGMM). In a simulation experiment, we used a simple fetus model that had five body parts and performed structured random movements in a womb-like environment. It was shown that the method could estimate the number of body parts and kinematic structures without any pre-existing knowledge in many cases. Another experiment showed that the degree of motor coordination in random movements affects the result of body schema formation strongly. It is confirmed that the accuracy rate for body schema estimation had the highest value 84.6% when the ratio of motor coordination was 0.9 in our setting. These results suggest that kinematic structure can be estimated from tactile information obtained by a fetus moving randomly in a womb without any visual information even though its accuracy was not so high. They also suggest that a certain degree of motor coordination in random movements and the sufficient dimension of state space that represents the body map are important to estimate body schema correctly.


A New Method for Classification of Datasets for Data Mining

arXiv.org Machine Learning

Humans have been manually extracting patterns from data for centuries, but the increasing volume of data in modern times has called for more automated approaches. Information leads to power and success, and thanks to sophisticated technologies such as computers, satellites, etc., we have been collecting tremendous amounts of information. Initially, with the advent of computers and means for mass digital storage, we started collecting and storing all sorts of data, counting on the power of computers to help sort through this amalgam of information. Unfortunately, these massive collections of data stored on disparate structures very rapidly became overwhelming. A variety of information collected in digital form in databases and in flat files.


Implementing your own k-nearest neighbour algorithm using Python

#artificialintelligence

In machine learning, you may often wish to build predictors that allows to classify things into categories based on some set of associated values. For example, it is possible to provide a diagnosis to a patient based on data from previous patients. Many algorithms have been developed for automated classification, and common ones include random forests, support vector machines, Naรฏve Bayes classifiers, and many types of neural networks. To get a feel for how classification works, we take a simple example of a classification algorithm โ€“ k-Nearest Neighbours (kNN) โ€“ and build it from scratch in Python 2. You can use a mostly imperative style of coding, rather than a declarative/functional one with lambda functions and list comprehensions to keep things simple if you are starting with Python. Here, we will provide an introduction to the latter approach.


k-nearest neighbor algorithm using Python

@machinelearnbot

The example used to illustrate the method in the source code is the famous iris data set, consisting of 3 clusters, 150 observations, and 4 variables, first analysed in 1936. How does the methodology perform on large data sets with many variables, or on unstructured data? Why was Python chosen to do this analysis? I think this is great, but I would be interested to know the motivation. The author mentioned other clustering techniques, such as SVM, Naive Bayes (issued from statistical science) or neural networks.


Machine learning PREDICTIVE ANALYTICS REPORT โ€“ The Art of Service

#artificialintelligence

Breakouts in the Machine learning predictive analytics are MATLAB, Regression analysis, Sentiment analysis. Seriously consider these technologies to gain a strategic advantage. The technologies who are at the peak of their interest are TensorFlow, Azure machine learning studio, KNIME. By far most employment needs are found in the MATLAB, Data science, Splunk technologies. These 3 fields have the most active practitioners who have the specific skill set or experience: Data science, Artificial Intelligence, learning management system.


How Bayesian Inference Works

#artificialintelligence

Bayesian inference is a way to get sharper predictions from your data. It's particularly useful when you don't have as much data as you would like and want to juice every last bit of predictive strength from it. Although it is sometimes described with reverence, Bayesian inference isn't magic or mystical. And even though the math under the hood can get dense, the concepts behind it are completely accessible. In brief, Bayesian inference lets you draw stronger conclusions from your data by folding in what you already know about the answer.


Deploying Predictive Models

@machinelearnbot

Over the last decade, we have seen tremendous interest in the application of data mining and statistical algorithms, first in research and science and, more recently across various industries, that has led to the development of myriad solutions by the data science community. Most of the times data science algorithms are built standalone on platforms like R or python etc. In order to build a data-driven product or use these algorithms for real-time predictions it's essential these algorithms get integrated or ported over to the application stack. Let's say your data Science team has built an amazingly accurate model in R using some package which has a built-in algorithm and we are ready to put it to work. However application servers run on Java, and this particular package is not available in Java.