014CSEARUNNACHALAMRS
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12 slides
Aug 04, 2024
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About This Presentation
This presentation on the Naive Bayes Algorithm offers an in-depth exploration of this simple yet powerful probabilistic classifier. It covers the fundamental principles, including the Bayes Theorem, and how Naive Bayes assumes independence between predictors. The PPT highlights various applications,...
This presentation on the Naive Bayes Algorithm offers an in-depth exploration of this simple yet powerful probabilistic classifier. It covers the fundamental principles, including the Bayes Theorem, and how Naive Bayes assumes independence between predictors. The PPT highlights various applications, such as spam detection, sentiment analysis, and medical diagnosis. Through practical examples and visual aids, the presentation elucidates the algorithm's efficiency and ease of implementation. It also addresses potential limitations and ways to overcome them, making it a valuable resource for both beginners and seasoned data scientists.
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Language: en
Added: Aug 04, 2024
Slides: 12 pages
Slide Content
Introduction to Naive Bayes Algorithm Naïve Bayes algorithm is a supervised learning algorithm, which is based on Bayes theorem and used for solving classification problems. It is a probabilistic classifier, which means it predicts on the basis of the probability of an object. Some popular examples of Naïve Bayes Algorithm are spam filtration, Sentimental analysis, and classifying articles. Contact me For PPT Making - -> https://www.fiverr.com/ppt
Mathematical Formulation of Naive Bayes P(A|B) is Posterior probability: Probability of hypothesis A on the observed event B. P(B|A) is Likelihood probability: Probability of the evidence given that the probability of a hypothesis is true. P(A) is Prior Probability: Probability of hypothesis before observing the evidence . P(B) is Marginal Probability: Probability of Evidence. Contact me For PPT Making - -> https://www.fiverr.com/ppt
Working of Naïve Bayes' Classifier: Working of Naïve Bayes' Classifier can be understood with the help of the below example: Suppose we have a dataset of weather conditions and corresponding target variable "Play". So using this dataset we need to decide that whether we should play or not on a particular day according to the weather conditions. So to solve this problem, we need to follow the below steps: Convert the given dataset into frequency tables. Generate Likelihood table by finding the probabilities of given features. Now, use Bayes theorem to calculate the posterior probability. Problem: If the weather is sunny, then the Player should play or not? Solution: To solve this, first consider the below dataset: Contact me For PPT Making - -> https://www.fiverr.com/ppt
Working of Naïve Bayes' Classifier:
Working of Naïve Bayes' Classifier: Contact me For PPT Making - -> https://www.fiverr.com/ppt
Working of Naïve Bayes' Classifier: Applying Bayes'theorem : P( Yes|Sunny )= P( Sunny|Yes )*P(Yes)/P(Sunny) P( Sunny|Yes )= 3/10= 0.3 P(Sunny)= 0.35 P(Yes)=0.71 So P( Yes|Sunny ) = 0.3*0.71/0.35= 0.60 P( No|Sunny )= P( Sunny|No )*P(No)/P(Sunny) P( Sunny|NO )= 2/4=0.5 P(No)= 0.29 P(Sunny)= 0.35 So P( No|Sunny )= 0.5*0.29/0.35 = 0.41 So as we can see from the above calculation that P( Yes|Sunny )>P( No|Sunny ) Hence on a Sunny day, Player can play the game.
Working of Naïve Bayes' Classifier Data Preprocessing The input data is cleaned, transformed, and organized to prepare it for the algorithm. Probability Calculation The algorithm calculates the conditional probabilities of each feature given the target class. Classification New instances are classified by applying Bayes' Theorem to determine the most likely class.
Types of Naïve Bayes Model Gaussian Naive Bayes Assumes that features follow a Gaussian (normal) distribution. Useful for continuous data like age, income, or test scores. Multinomial Naive Bayes Handles discrete features like word counts, making it suitable for text classification tasks like document categorization. Bernoulli Naive Bayes Treats features as binary (present or absent), making it ideal for problems like spam detection or medical diagnosis. Categorical Naive Bayes Manages categorical features with more than two possible values, such as product categories or movie genres. Contact me For PPT Making - -> https://www.fiverr.com/ppt
Projects Using Naive Bayes Spam Email Detection Naive Bayes is widely used to build spam email filtering systems that can accurately classify incoming messages as spam or ham based on content and header features. Sentiment Analysis The algorithm's ability to handle textual data makes it a popular choice for sentiment analysis tasks, such as classifying product reviews as positive, negative, or neutral. Medical Diagnosis Naive Bayes can be used in medical applications to assist with disease diagnosis by analyzing patient symptoms, test results, and other relevant factors. Document Classification Naive Bayes is often employed in text classification problems, like categorizing news articles, research papers, or legal documents based on their content.
Advantages and Disadvantages of Naive Bayes Advantages Naive Bayes is a simple yet powerful algorithm that can perform well on complex problems. It's easy to implement, computationally efficient, and can handle both continuous and categorical data. Flexibility The algorithm can be easily adapted to different types of classification problems, from spam detection to sentiment analysis and medical diagnosis. Robustness Naive Bayes is relatively robust to noisy or irrelevant features, making it suitable for real-world datasets with diverse variables. Disadvantages The independence assumption is often violated in real-world data, leading to suboptimal performance. Naive Bayes also struggles with highly correlated features and cannot model complex relationships between variables. Contact me For PPT Making - -> https://www.fiverr.com/ppt
Conclusion The Naive Bayes algorithm is a powerful and versatile machine learning technique with a wide range of applications. Despite its simplistic assumptions, it can deliver impressive performance in real-world scenarios, making it a go-to choice for many data scientists and researchers. Contact me For PPT Making - -> https://www.fiverr.com/ppt
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