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How to code Logistic Regression from scratch with NumPy


Let's first think of the underlying math that we want to use. In the above equations, X is the input matrix that contains observations on the row axis and features on the column axis; y is a column vector that contains the classification labels (0 or 1); f is the sum of squared errors loss function; h is the loss function for the MLE method. So, this is our goal: translate the above equations into code. We plan to use an object-oriented approach for implementation. We'll create a LogisticRegression class with 3 public methods: fit(), predict(), and accuracy().

Understanding Reinforcement Learning Hands-On: The Bellman Equation pt.1


Welcome to the fifth entry on a series on Reinforcement Learning. In the previous article, we presented the MDP Framework for describing complex environments. This allowed us to create a more robust and diverse scenario for the basic Multi-Armed Bandits problem, which we called the Casinos Environment. We then implemented this scenario using OpenAI's gym, and made a simple agent that acted randomly to showcase how an interaction is realized under the MDP Framework. Today, we're going to focus back on the agents, and show a way in which we can describe an agent's behavior in complex scenarios, where past actions determine future rewards.

Hash Tables in Data Structure and Algorithm


The above data structures all of these operations can be guaranteed to be in O(Logn) time. So can we perform it with O(1) time? this is why the hash table comes in. The simplest method to build Hash function is each key, we can perform sum of each key by add all character and then we can use Modulo for M. M is typically a prime number and it is the size of Hash array. I just suppose in a simple case of password but in real life, we must encode password (this is not the purpose of this article and apply a ton of algorithm for encoding password).

Moment Generating Function for Probability Distribution with Python


This tutorial's code is available on Github and its full implementation as well on Google Colab. Check out our editorial suggestions on the best data science books. We generally use moments in statistics, machine learning, mathematics, and other fields to describe the characteristics of a distribution. Let's say the variable of our interest is X then, moments are X's expected values. Now we are very familiar with the first moment(mean) and the second moment(variance).

An intuitive guide to differencing time series in Python


While working with time series, sooner or later you will encounter the term differencing. In this article, I will do my best to provide a simple and easy on the maths introduction to the theory. Then, I will also show two different approaches you can follow in Python. Before I actually explain what differencing is, I need to quickly introduce another concept which is crucial when working with time series data -- stationarity. There are quite a few great articles out there going deeply into what stationarity is, including the distinction between weak and strong variants, etc. However, for the sake of this article, we will focus on a very basic definition.

A Complete Anomaly Detection Algorithm From Scratch in Python: Step by Step Guide


Anomaly detection can be treated as a statistical task as an outlier analysis. But if we develop a machine learning model, it can be automated and as usual, can save a lot of time. There are so many use cases of anomaly detection. Credit card fraud detection, detection of faulty machines, or hardware systems detection based on their anomalous features, disease detection based on medical records are some good examples. There are many more use cases.

May attacks 'ill-conceived' planning reforms

BBC News

Theresa May has criticised the government's proposed changes to the planning system for being "ill-conceived" and "mechanistic". The former prime minister said the use of a formula to assess housing need in England "does not guarantee a single extra home being built". The Commons is debating a motion from another Tory MP, asking ministers to think again about its reforms. The government said the plan was "still part of a consultation". A Ministry of Housing, Communities and Local Government (MHCLG) spokeswoman added that the algorithm would be designed to "set up to deliver the new homes the country needs".

Logistic Regression Clearly Explained


Logistic Regression is the most widely used classification algorithm in machine learning. It is used in many real-world scenarios like spam detected, cancer detection, IRIS dataset, etc. Mostly it is used in binary classification problems. But it can also be used in multiclass classification. Logistic Regression predicts the probability that the given data point belongs to a certain class or not. In this article, I will be using the famous heart disease dataset from Kaggle.

Artificial intelligence - Jean-Christophe Hérault (IFF) - Nez le mouvement culturel olfactif


Artificial intelligence programs are gradually becoming part of the perfume development process. In what way does perfumers' work engage with these new methods? How can we reconcile this rational, mathematical approach with a creative process requiring sensitivity and subjectivity? Is the future of perfumers at risk? Jean-Christophe Hérault, senior perfumer at IFF, explains the implications of what is sometimes referred to as a revolution, while reminding us of the importance of human intuition. What do artificial intelligence programs used in fragrance creation consist of?

Learning Concepts Described by Weight Aggregation Logic Artificial Intelligence

We consider weighted structures, which extend ordinary relational structures by assigning weights, i.e. elements from a particular group or ring, to tuples present in the structure. We introduce an extension of first-order logic that allows to aggregate weights of tuples, compare such aggregates, and use them to build more complex formulas. We provide locality properties of fragments of this logic including Feferman-Vaught decompositions and a Gaifman normal form for a fragment called FOW1, as well as a localisation theorem for a larger fragment called FOWA1. This fragment can express concepts from various machine learning scenarios. Using the locality properties, we show that concepts definable in FOWA1 over a weighted background structure of at most polylogarithmic degree are agnostically PAC-learnable in polylogarithmic time after pseudo-linear time preprocessing.