Category Archives: Data Science

Mean Squared Error or R-Squared – Which one to use?

Mean Squared Error Representation

As you embark on your journey to understand and evaluate the performance of regression models, it’s crucial to know when to use each of these metrics and what they reveal about your model’s accuracy. In this post, you will learn about the concepts of the mean-squared error (MSE) and R-squared, the difference between them, and which one to use when evaluating the linear regression models. You also learn Python examples to understand the concepts in a better manner What is Mean Squared Error (MSE)? The Mean squared error (MSE) represents the error of the estimator or predictive model created based on the given set of observations in the sample. It …

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Mean Squared Error vs Cross Entropy Loss Function

As a data scientist, understanding the nuances of various loss functions is critical for building effective machine learning models. Choosing the right loss function can significantly impact the performance of your model and determine how well it generalizes to unseen data. In this blog post, we will delve into two widely used loss functions: Mean Squared Error (MSE) and Cross Entropy Loss. By comparing their properties, applications, and trade-offs, we aim to provide you with a solid foundation for selecting the most suitable loss function for your specific problem. Loss functions play a pivotal role in training machine learning models as they quantify the difference between the model’s predictions and …

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Data Storytelling Explained with Examples

data storytelling key components

Have you ever told a story to someone, but they just didn’t seem to understand it? They might have been confused about the plot or why the characters acted in certain ways. If this has happened to you before, then you are not alone. Many people struggle with storytelling or rather data storytelling because they do not know how to communicate their data effectively to tell an engaging story. Data storytelling is a powerful tool that can be used to educate, inform or persuade an audience by using different kinds of narration. By using charts, graphs, images and other visuals, data can be made more interesting and engaging. Data storytelling …

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Quiz: Linear Regression & F-Statistics

Interview questions

Linear Regression is one of the most widely used statistical methods for predictive modeling in various fields such as finance, marketing, and engineering. It involves fitting a linear equation to a set of data points, which can be used to make predictions about new data. One important aspect of linear regression is the use of F-Statistics, which is a statistical test used to determine the significance of the regression model. If you’re looking to test your knowledge of Linear Regression and F-Statistics, you’ve come to the right place! It will also be helpful if you are preparing for data science interviews. In this capsule quiz, we’ve compiled 10 questions that …

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Mastering f-statistics in Linear Regression: Formula, Examples

linear regression R-squared concepts

In this blog post, we will take a look at the concepts and formula of f-statistics in linear regression models and understand with the help of examples. F-test and F-statistics are very important concepts to understand if you want to be able to properly interpret the summary results of training linear regression machine learning models. We will start by discussing the importance of f-statistics in building linear regression models and understand how they are calculated based on the formula of f-statistics. We will, then, understand the concept with some real-world examples. As data scientists, it is very important to understand both the f-statistics and t-statistics and how they help in …

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Dealing with Class Imbalance in Python: Techniques

As a data scientist, we are tasked with building machine learning (ML) models that can accurately predict outcomes based on input data. However, one of the biggest challenges in building ML models is dealing with class imbalance. Class imbalance occurs when the distribution of classes in your dataset is uneven, with one class significantly outnumbering one or more other classes. Class imbalance is a common problem in many industries, including fraud detection, medical diagnosis, and customer churn prediction, to name a few. Handling class imbalance correctly is crucial for data scientists, as it can have a significant impact on the performance of machine learning models. Failure to address class imbalance …

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Python – Draw Confusion Matrix using Matplotlib

Classification models are a fundamental part of machine learning and are used extensively in various industries. Evaluating the performance of these models is critical in determining their effectiveness and identifying areas for improvement. One of the most common tools used for evaluating classification models is the confusion matrix. It provides a visual representation of the model’s performance by displaying the number of true positives, false positives, true negatives, and false negatives. In this post, we will explore how to create and visualize confusion matrices in Python using Matplotlib. We will walk through the process step-by-step and provide examples that demonstrate the use of Matplotlib in creating clear and concise confusion …

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Degree of Freedom in Statistics: Meaning & Examples

degrees of freedom in statistics - meaning and examples

The degree of freedom (DOF) is a term that statisticians use to describe the degree of independence in statistical data. A degree of freedom can be thought of as the number of variables that are free to vary, given one or more constraints. When you have one degree, there is one variable that can be freely changed without affecting the value for any other variable. As a data scientist, it is important to understand the concept of degree of freedom, as it can help you do accurate statistical analysis and  validate the results. In this blog, we will explore the meaning of degree of freedom in statistics, its importance in …

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Different types of Time-series Forecasting Models

different types of time-series forecasting

Forecasting is the process of predicting future events based on past and present data. Time-series forecasting is a type of forecasting that predicts future events based on time-stamped data points. Time-series forecasting models are an essential tool for any organization or individual who wants to make informed decisions based on future events or trends. From stock market predictions to weather forecasting, time-series models help us to understand and forecast changes over time. However, with so many different types of models available, it can be challenging to determine which one is best suited for a particular scenario. There are many different types of time-series forecasting models, each with its own strengths …

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Support Vector Machine (SVM) Python Example

support vector machine - SVM

Support Vector Machines (SVMs) are a powerful and versatile machine learning algorithm that has gained widespread popularity among data scientists in recent years. SVMs are widely used for classification, regression, and outlier detection (one-class SVM), and have proven to be highly effective in solving complex problems in various fields, including computer vision (image classification, object detection, etc.), natural language processing (sentiment analysis, text classification, etc.), and bioinformatics (gene expression analysis, protein classification, disease diagnosis, etc.). In this post, you will learn about the concepts of Support Vector Machine (SVM)  with the help of  Python code example for building a machine learning classification model. We will work with Python Sklearn package for building the …

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Fixed vs Random vs Mixed Effects Models – Examples

fixed and random effects models

Have you ever wondered what fixed effect, random effect and mixed effects models are? Or, more importantly, how they differ from one another?  In this post, you will learn about the concepts of fixed and random effects models along with when to use fixed effects models and when to go for fixed + random effects (mixed) models. The concepts will be explained with examples. As data scientists, you must get a good understanding of these concepts as it would help you build better linear models such as general linear mixed models or generalized linear mixed models (GLMM).  What are fixed, random & mixed effects models? First, we will take a real-world example and try and understand …

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CNN Basic Architecture for Classification & Segmentation

image classification object detection image segmentation

As data scientists, we are constantly exploring new techniques and algorithms to improve the accuracy and efficiency of our models. When it comes to image-related problems, convolutional neural networks (CNNs) are an essential tool in our arsenal. CNNs have proven to be highly effective for tasks such as image classification and segmentation, and have even been used in cutting-edge applications such as self-driving cars and medical imaging. Convolutional neural networks (CNNs) are deep neural networks that have the capability to classify and segment images. CNNs can be trained using supervised or unsupervised machine learning methods, depending on what you want them to do. CNN architectures for classification and segmentation include …

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Python – Replace Missing Values with Mean, Median & Mode

Boxplot for deciding whether to use mean, mode or median for imputation

Missing values are common in dealing with real-world problems when the data is aggregated over long time stretches from disparate sources, and reliable machine learning modeling demands for careful handling of missing data. One strategy is imputing the missing values, and a wide variety of algorithms exist spanning simple interpolation (mean. median, mode), matrix factorization methods like SVD, statistical models like Kalman filters, and deep learning methods. Missing value imputation or replacing techniques help machine learning models learn from incomplete data. There are three main missing value imputation techniques – mean, median and mode. Mean is the average of all values in a set, median is the middle number in …

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Histogram and Density Plots in Python & R

histogram with different bin widths

In the world of data science, visualizing data is crucial to make sense of the information at hand. One of the most popular ways to visualize data is by using histograms and density plots. These visualizations help us understand the distribution of data and identify patterns that may not be apparent from raw numbers alone. In this blog, we will explore how to create histograms and density plots in two popular programming languages, Python and R.   As a data scientist, it is important to have a good understanding of these visualizations because they allow you to communicate your findings effectively. Histograms and density plots can help you see the …

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Feature Selection vs Feature Extraction: Machine Learning

Feature extraction vs feature selection

Machine learning has become an increasingly important tool for businesses and researchers alike in recent years. From identifying patterns in data to making predictions about future outcomes, machine learning algorithms are now being used in a wide variety of fields. However, the success of these algorithms often depends on the quality of the features used to train them. This is where the concepts of feature selection and feature extraction come in. In this blog post, we’ll explore the difference between feature selection and feature extraction, two key techniques used in machine learning to optimize feature sets for better model performance. Both feature selection and feature extraction are used for dimensionality …

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Neural Network & Multi-layer Perceptron Examples

Single layer neural network

Neural networks are an important part of machine learning, so it is essential to understand how they work. A neural network is a computer system that has been modeled based on a biological neural network comprising neurons connected with each other. It can be built to solve machine learning tasks, like classification and regression problems. The perceptron algorithm is a representation of how neural networks work. The artificial neurons were first proposed by Frank Rosenblatt in 1957 as models for the human brain’s perception mechanism. This post will explain the basics of neural networks with a perceptron example. You will understand how a neural network is built using perceptrons. This …

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